2024-04-12 19:18:02 +08:00
<!DOCTYPE html>
< html lang = "en" >
< head >
< meta charset = "utf-8" >
< meta name = "viewport" content = "width=device-width, initial-scale=1.0" >
< meta name = "generator" content = "rustdoc" >
< title > Rust Custom Target for QEMU RISC-V on Apache NuttX RTOS< / title >
<!-- Begin scripts/articles/* - header.html: Article Header for Custom Markdown files processed by rustdoc, like chip8.md -->
< meta property = "og:title"
content="Rust Custom Target for QEMU RISC-V on Apache NuttX RTOS"
data-rh="true">
< meta property = "og:description"
2024-04-18 23:36:42 +08:00
content="Our Rust App compiles for Software Floating-Point, but Apache NuttX RTOS expects Hardware Floating-Point... Let's fix this with a Rust Custom Target for QEMU RISC-V"
2024-04-12 19:18:02 +08:00
data-rh="true">
< meta name = "description"
2024-04-18 23:36:42 +08:00
content="Our Rust App compiles for Software Floating-Point, but Apache NuttX RTOS expects Hardware Floating-Point... Let's fix this with a Rust Custom Target for QEMU RISC-V">
2024-04-12 19:18:02 +08:00
< meta property = "og:image"
content="https://lupyuen.github.io/images/rust4-title.jpg">
< meta property = "og:type"
content="article" data-rh="true">
< link rel = "canonical"
href="https://lupyuen.codeberg.page/articles/rust4.html" />
<!-- End scripts/articles/* - header.html -->
<!-- Begin scripts/rustdoc - header.html: Header for Custom Markdown files processed by rustdoc, like chip8.md -->
< link rel = "alternate" type = "application/rss+xml" title = "RSS Feed for lupyuen" href = "/rss.xml" / >
< link rel = "stylesheet" type = "text/css" href = "../normalize.css" >
< link rel = "stylesheet" type = "text/css" href = "../rustdoc.css" id = "mainThemeStyle" >
< link rel = "stylesheet" type = "text/css" href = "../dark.css" >
< link rel = "stylesheet" type = "text/css" href = "../light.css" id = "themeStyle" >
< link rel = "stylesheet" type = "text/css" href = "../prism.css" >
< script src = "../storage.js" > < / script > < noscript >
< link rel = "stylesheet" href = "../noscript.css" > < / noscript >
< link rel = "shortcut icon" href = "../favicon.ico" >
< style type = "text/css" >
#crate-search {
background-image: url("../down-arrow.svg");
}
< / style >
<!-- End scripts/rustdoc - header.html -->
< / head >
< body class = "rustdoc" >
<!-- [if lte IE 8]>
< div class = "warning" >
This old browser is unsupported and will most likely display funky
things.
< / div >
<![endif]-->
<!-- Begin scripts/rustdoc - before.html: Pre - HTML for Custom Markdown files processed by rustdoc, like chip8.md -->
<!-- Begin Theme Picker -->
< div class = "theme-picker" style = "left: 0" > < button id = "theme-picker" aria-label = "Pick another theme!" > < img src = "../brush.svg"
width="18" alt="Pick another theme!">< / button >
< div id = "theme-choices" > < / div >
< / div >
<!-- Theme Picker -->
<!-- End scripts/rustdoc - before.html -->
< h1 class = "title" > Rust Custom Target for QEMU RISC-V on Apache NuttX RTOS< / h1 >
< nav id = "TOC" > < ul >
2024-04-13 00:51:30 +08:00
< li > < a href = "#software-vs-hardware-floating-point" > 1 Software vs Hardware Floating-Point< / a > < ul > < / ul > < / li >
2024-04-15 08:44:59 +08:00
< li > < a href = "#rust-wont-double-float" > 2 Rust Won’ < / a > < ul > < / ul > < / li >
2024-04-13 23:25:52 +08:00
< li > < a href = "#custom-target-for-rust" > 3 Custom Target for Rust< / a > < ul > < / ul > < / li >
< li > < a href = "#build-the-rust-core-library" > 4 Build the Rust Core Library< / a > < ul > < / ul > < / li >
< li > < a href = "#nuttx-links-ok-with-rust" > 5 NuttX Links OK with Rust< / a > < ul > < / ul > < / li >
< li > < a href = "#rust-build-for-64-bit-risc-v" > 6 Rust Build for 64-bit RISC-V< / a > < ul > < / ul > < / li >
2024-04-15 07:36:02 +08:00
< li > < a href = "#whats-next" > 7 What’ < / a > < ul > < / ul > < / li >
2024-07-23 10:59:58 +08:00
< li > < a href = "#appendix-build-nuttx-for-qemu" > 8 Appendix: Build NuttX for QEMU< / a > < ul > < / ul > < / li >
< li > < a href = "#appendix-rust-compiler-options" > 9 Appendix: Rust Compiler Options< / a > < ul > < / ul > < / li > < / ul > < / nav > < p > 📝 < em > 21 Apr 2024< / em > < / p >
2024-04-12 19:18:02 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-title.jpg" alt = "Rust Apps on Apache NuttX RTOS and QEMU RISC-V" / > < / p >
2024-04-12 19:40:46 +08:00
< div style = "text-align: center" >
< p > < a href = "https://github.com/Swordfish90/cool-retro-term" > < em > Thanks to cool-retro-term!< / em > < / a > < / p >
< / div >
2024-04-19 14:03:39 +08:00
< p > Last article we were compiling < a href = "https://lupyuen.github.io/articles/rust3" > < strong > Rust Apps< / strong > < / a > for < a href = "https://nuttx.apache.org/docs/latest/index.html" > < strong > Apache NuttX RTOS< / strong > < / a > (QEMU Emulator, RISC-V 32-bit). And we hit a < strong > baffling error< / strong > …< / p >
2024-04-13 00:51:30 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > $ make
riscv64-unknown-elf-ld: libapps.a
hello_rust_1.o:
can' t link soft-float modules with double-float modules
< / code > < / pre > < / div >
< p > Let’ < strong > C-to-Rust Interop< / strong > …< / p >
< ul >
< li >
2024-04-18 18:55:16 +08:00
< p > Rust compiles for < strong > Soft-Float< / strong > , NuttX expects < strong > Double-Float< / strong > < / p >
2024-04-13 00:51:30 +08:00
< p > (Software vs Hardware Floating-Point)< / p >
< / li >
< li >
< p > But Rust < strong > doesn’ < / strong > (by default)< / p >
< / li >
< li >
< p > So we create a < strong > Rust Custom Target< / strong > for Double-Float< / p >
< / li >
< li >
< p > Rebuild the < strong > Rust Core Library< / strong > for Double-Float< / p >
< / li >
< li >
< p > And our Rust App < strong > builds OK with NuttX< / strong > !< / p >
< / li >
< / ul >
2024-04-17 22:56:36 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-flow2a.jpg" alt = "Double-Float vs Soft-Float: GCC Linker won’ / > < / p >
2024-04-13 00:51:30 +08:00
< h1 id = "software-vs-hardware-floating-point" > < a class = "doc-anchor" href = "#software-vs-hardware-floating-point" > §< / a > 1 Software vs Hardware Floating-Point< / h1 >
2024-04-18 23:36:42 +08:00
< p > < em > Why did our NuttX Build fail? (Pic above)< / em > < / p >
2024-04-18 14:50:16 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Download the NuttX Source Code
$ mkdir nuttx
$ cd nuttx
$ git clone https://github.com/apache/nuttx nuttx
$ git clone https://github.com/apache/nuttx-apps apps
2024-04-18 23:36:42 +08:00
## Configure NuttX for QEMU RISC-V 32-bit
2024-04-18 14:50:16 +08:00
$ cd nuttx
$ tools/configure.sh rv-virt:nsh
$ make menuconfig
## TODO: Enable " Hello Rust Example"
## Build NuttX bundled with the Rust App
2024-04-18 00:38:42 +08:00
$ make
2024-04-16 03:01:04 +08:00
riscv64-unknown-elf-ld: libapps.a
hello_rust_1.o:
can' t link soft-float modules with double-float modules
< / code > < / pre > < / div >
2024-04-18 23:36:42 +08:00
< p > < a href = "https://lupyuen.github.io/articles/rust3#build-nuttx-for-qemu-risc-v" > (See the < strong > Complete Steps< / strong > )< / a > < / p >
2024-04-18 00:38:42 +08:00
< p > < strong > GCC Linker< / strong > failed because it couldn’ < / p >
< p > Here’ < strong > GCC Compiler< / strong > to compile our C Modules…< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Build NuttX Firmware with Tracing Enabled
$ make --trace
2024-04-12 19:40:46 +08:00
...
2024-04-16 03:01:04 +08:00
## GCC compiles `hello_main.c` to `hello.o`
2024-04-18 00:38:42 +08:00
## for RISC-V 32-bit with Double-Float
2024-04-12 19:40:46 +08:00
riscv64-unknown-elf-gcc \
2024-04-16 23:00:41 +08:00
-march=rv32imafdc \
-mabi=ilp32d \
2024-04-12 19:40:46 +08:00
-c \
hello_main.c \
2024-04-18 00:38:42 +08:00
-o ...hello.o \
...
2024-04-15 10:45:47 +08:00
< / code > < / pre > < / div >
2024-04-18 00:38:42 +08:00
< p > < a href = "https://gist.github.com/lupyuen/7e68b69d0d5879f77b1404ae2db6fb9d" > (See the < strong > GCC Options< / strong > )< / a > < / p >
2024-04-16 03:21:05 +08:00
< p > Then NuttX Build calls < strong > Rust Compiler< / strong > to compile our Rust App…< / p >
2024-04-18 00:38:42 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Build NuttX Firmware with Tracing Enabled
$ make --trace
2024-04-16 03:01:04 +08:00
...
## Rust Compiler compiles `hello_rust_main.rs` to `hello_rust.o`
2024-04-18 00:38:42 +08:00
## for RISC-V 32-bit with Soft-Float
2024-04-15 10:45:47 +08:00
rustc \
2024-04-16 23:00:41 +08:00
--target riscv32i-unknown-none-elf \
2024-04-15 10:45:47 +08:00
--edition 2021 \
--emit obj \
-g \
-C panic=abort \
-O \
hello_rust_main.rs \
2024-04-18 00:38:42 +08:00
-o ...hello_rust.o
2024-04-15 10:45:47 +08:00
< / code > < / pre > < / div >
2024-04-18 00:38:42 +08:00
< p > Which looks like this…< / p >
2024-04-17 23:16:58 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-flow2b.jpg" alt = "Double-Float vs Soft-Float: GCC Linker won’ / > < / p >
2024-04-16 03:21:05 +08:00
< p > < em > Is there a problem?< / em > < / p >
2024-04-17 23:16:58 +08:00
< p > Watch closely as we compare < strong > GCC Compiler< / strong > with < strong > Rust Compiler< / strong > (pic above)…< / p >
2024-04-15 11:32:01 +08:00
< span style = "font-size:90%" >
2024-04-18 00:38:42 +08:00
< div > < table > < thead > < tr > < th style = "text-align: left" > GCC Compiler< / th > < th style = "text-align: left" > Rust Compiler< / th > < / tr > < / thead > < tbody >
< tr > < td style = "text-align: left" > < em > riscv64-unknown-elf-gcc< / em > < br > < em > hello_main.c< / em > < / td > < td style = "text-align: left" > < em > rustc< / em > < br > < em > hello_rust_main.rs< / em > < / td > < / tr >
< tr > < td style = "text-align: left" > < em > -march< / em > < br > < strong > rv32imafdc< / strong > < / td > < td style = "text-align: left" > < em > – < / em > < br > < strong > riscv32i-unknown-none-elf< / strong > < / td > < / tr >
< tr > < td style = "text-align: left" > < em > -mabi< / em > < br > < strong > ilp32d< / strong > < / td > < td style = "text-align: left" > < / td > < / tr >
2024-04-15 10:45:47 +08:00
< / tbody > < / table >
2024-04-15 11:32:01 +08:00
< / div > < / span >
2024-04-18 15:24:37 +08:00
< p > < em > Hmmm the Floats look different…< / em > < / p >
2024-04-18 23:36:42 +08:00
< p > GCC compiles for (Double-Precision) < strong > Hardware Floating-Point< / strong > …< / p >
2024-04-19 14:03:39 +08:00
< p > But Rust Compiler emits < strong > Software Floating-Point< / strong > .< / p >
< p > That’ < strong > won’ < / strong > : Hard-Float vs Soft-Float!< / p >
2024-04-15 11:32:01 +08:00
< span style = "font-size:90%" >
2024-04-18 00:38:42 +08:00
< div > < table > < thead > < tr > < th style = "text-align: left" > GCC Compiler< / th > < th style = "text-align: left" > Rust Compiler< / th > < / tr > < / thead > < tbody >
< tr > < td style = "text-align: left" > < strong > rv32imafdc< / strong > < / td > < td style = "text-align: left" > < strong > riscv32i< / strong > < / td > < / tr >
< tr > < td style = "text-align: left" > - < strong > I< / strong > : Integer< / td > < td style = "text-align: left" > - < strong > I< / strong > : Integer< / td > < / tr >
< tr > < td style = "text-align: left" > - < strong > F< / strong > : Single Hard-Float< / td > < td style = "text-align: left" > < em > (Default is Soft-Float)< / em > < / td > < / tr >
< tr > < td style = "text-align: left" > - < strong > D< / strong > : Double Hard-Float< / td > < td style = "text-align: left" > < em > (Default is Soft-Float)< / em > < / td > < / tr >
2024-04-15 11:32:01 +08:00
< / tbody > < / table >
< / div > < / span >
2024-04-16 16:51:10 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-flow2.jpg" alt = "Double-Float vs Soft-Float: GCC Linker won’ / > < / p >
2024-04-19 14:03:39 +08:00
< p > To verify, we dump the < a href = "https://en.wikipedia.org/wiki/Executable_and_Linkable_Format#File_header" > < strong > ELF Header< / strong > < / a > for < strong > GCC Compiler Output< / strong > …< / p >
2024-04-18 00:38:42 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Dump the ELF Header for GCC Output
2024-04-15 10:45:47 +08:00
$ riscv64-unknown-elf-readelf \
--file-header --arch-specific \
../apps/examples/hello/*hello.o
2024-04-19 14:03:39 +08:00
## GCC Compiler Output is
## Double-Precision Hardware Floating-Point
2024-04-18 00:38:42 +08:00
Flags: 0x5, RVC, double-float ABI
< / code > < / pre > < / div >
< p > < a href = "https://gist.github.com/lupyuen/d8b4f793cd463230393326cef7dbedbe" > (See the < strong > GCC ELF Header< / strong > )< / a > < / p >
< p > And the ELF Header for < strong > Rust Compiler Output< / strong > …< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Dump the ELF Header for Rust Compiler Output
2024-04-15 10:45:47 +08:00
$ riscv64-unknown-elf-readelf \
--file-header --arch-specific \
../apps/examples/hello_rust/*hello_rust.o
2024-04-19 14:03:39 +08:00
## Rust Compiler Output is
## Software Floating-Point
2024-04-18 00:38:42 +08:00
Flags: 0x0
2024-04-15 10:45:47 +08:00
< / code > < / pre > < / div >
2024-04-18 00:38:42 +08:00
< p > < a href = "https://gist.github.com/lupyuen/413830fed9cdb2b02d5f9d0d062beb3e" > (See the < strong > Rust ELF Header< / strong > )< / a > < / p >
2024-04-16 23:00:41 +08:00
< p > Indeed we have a problem: Double-Float and Soft-Float won’ ’ < / p >
2024-04-17 22:35:27 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-flow3.jpg" alt = "Rust Won’ / > < / p >
2024-04-15 08:44:59 +08:00
< h1 id = "rust-wont-double-float" > < a class = "doc-anchor" href = "#rust-wont-double-float" > §< / a > 2 Rust Won’ < / h1 >
2024-04-17 22:35:27 +08:00
< p > < em > What if we ask Rust Compiler to compile for Double-Float? RV32IMAFDC (Pic above)< / em > < / p >
2024-04-18 11:53:04 +08:00
< p > Let’ < / p >
< ul >
< li >
2024-04-20 00:10:31 +08:00
< p > Our Build Target is < a href = "https://www.qemu.org/docs/master/system/riscv/virt.html" > < strong > QEMU Emulator< / strong > < / a > < / p >
< / li >
< li >
< p > Which offically supports < a href = "https://www.qemu.org/docs/master/system/riscv/virt.html#supported-devices" > < strong > < code > riscv32gc< / code > < / strong > < / a > < / p >
2024-04-18 11:53:04 +08:00
< / li >
< li >
< p > “< strong > < code > gc< / code > < / strong > ” in “< strong > < code > riscv32gc< / code > < / strong > ” denotes < a href = "https://en.wikipedia.org/wiki/RISC-V#ISA_base_and_extensions" > < strong > IMAFDC< / strong > < / a > < / p >
< / li >
< / ul >
2024-04-18 15:24:37 +08:00
< p > Hence we could do this…< / p >
2024-04-16 23:00:41 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Compile `hello_rust_main.rs` to `hello_rust.o`
## for Double-Precision Hardware Floating-Point
rustc \
--target riscv32gc-unknown-none-elf \
--edition 2021 \
--emit obj \
-g \
-C panic=abort \
-O \
hello_rust_main.rs \
-o hello_rust.o
< / code > < / pre > < / div >
2024-04-18 15:24:37 +08:00
< p > Sorry nope it < strong > won’ < / strong > …< / p >
2024-04-16 23:00:41 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > Error loading target specification:
Could not find specification for target " riscv32gc-unknown-none-elf" .
Run `rustc --print target-list` for a list of built-in targets
< / code > < / pre > < / div >
2024-04-17 22:56:36 +08:00
< p > That’ < strong > < code > riscv32gc< / code > < / strong > isn’ < strong > Built-In Rust Target< / strong > …< / p >
2024-04-19 14:03:39 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## List the Built-In Rust Targets for RISC-V
2024-04-16 23:00:41 +08:00
$ rustup target list | grep riscv
2024-04-19 14:03:39 +08:00
## Nope no riscv32gc!
2024-04-12 19:40:46 +08:00
riscv32i-unknown-none-elf
riscv32imac-unknown-none-elf
riscv32imc-unknown-none-elf
riscv64gc-unknown-linux-gnu
riscv64gc-unknown-none-elf
riscv64imac-unknown-none-elf
< / code > < / pre > < / div >
2024-04-19 15:32:50 +08:00
< p > But we can create a < a href = "https://docs.rust-embedded.org/embedonomicon/custom-target.html" > < strong > Custom Rust Target< / strong > < / a > for < strong > < code > riscv32gc< / code > < / strong > .< / p >
2024-04-18 15:24:37 +08:00
< p > (Coming up next section)< / p >
2024-04-16 23:00:41 +08:00
< p > < em > Won’ < / em > < / p >
2024-04-17 22:56:36 +08:00
< p > When we list the < strong > Built-In GCC Targets< / strong > …< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## List the Built-In Targets for GCC RISC-V.
2024-04-16 23:00:41 +08:00
## ABI means Application Binary Interface
$ riscv64-unknown-elf-gcc --target-help
Supported ABIs (for use with the -mabi= option):
ilp32 ilp32d ilp32e ilp32f lp64 lp64d lp64f
< / code > < / pre > < / div >
< p > We see that < strong > GCC supports Double-Float< / strong > : < strong > < code > ilp32d< / code > < / strong > < / p >
2024-04-12 19:40:46 +08:00
< ul >
2024-04-16 23:00:41 +08:00
< li > < strong > < code > ilp32< / code > < / strong > : < strong > 32-bit< / strong > Int, Long and Pointer< / li >
< li > < strong > < code > d< / code > < / strong > : < strong > Double-Precision< / strong > Hardware Floating-Point< / li >
2024-04-12 19:40:46 +08:00
< / ul >
2024-04-16 23:00:41 +08:00
< p > That’ < strong > < code > ilp32d< / code > < / strong > earlier…< / p >
2024-04-16 23:55:48 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## GCC compiles for RISC-V 32-bit (Double-Float)
2024-04-16 23:00:41 +08:00
riscv64-unknown-elf-gcc \
-march=rv32imafdc \
-mabi=ilp32d \
...
2024-04-15 07:36:02 +08:00
< / code > < / pre > < / div >
2024-04-18 15:24:37 +08:00
< p > We’ < / p >
2024-04-19 14:03:39 +08:00
< p > < a href = "https://gcc.gnu.org/onlinedocs/gcc/RISC-V-Options.html#index-mabi-5" > (More about < strong > Application Binary Interface< / strong > )< / a > < / p >
2024-04-17 22:56:36 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-flow1a.jpg" alt = "Custom Target for Rust" / > < / p >
2024-04-15 07:36:02 +08:00
< h1 id = "custom-target-for-rust" > < a class = "doc-anchor" href = "#custom-target-for-rust" > §< / a > 3 Custom Target for Rust< / h1 >
2024-04-16 23:55:48 +08:00
< p > < em > To compile Rust for Double-Float, we need a Custom Target: riscv32gc< / em > < / p >
< p > < em > How to create the Custom Target?< / em > < / p >
2024-04-17 08:49:53 +08:00
< p > According to the < a href = "https://docs.rust-embedded.org/embedonomicon/custom-target.html" > < strong > Official Rust Docs< / strong > < / a > , we shall…< / p >
< ul >
< li >
2024-04-17 22:56:36 +08:00
< p > Copy from a < strong > Built-In Rust Target< / strong > < / p >
2024-04-17 08:49:53 +08:00
< p > (Like < strong > < code > riscv32i< / code > < / strong > )< / p >
< / li >
< li >
< p > Tweak it to fit our < strong > Custom Rust Target< / strong > < / p >
< p > (Which becomes < strong > < code > riscv32gc< / code > < / strong > )< / p >
< / li >
< / ul >
2024-04-18 23:36:42 +08:00
< p > This is how we dump a Built-In Rust Target: < a href = "https://gist.github.com/lupyuen/dd6a2ee58902e7925efd2a889bc0a833" > < strong > < code > riscv32i< / code > < / strong > < / a > < / p >
2024-04-17 22:56:36 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Dump the Built-In Rust Target:
2024-04-16 23:55:48 +08:00
## riscv32i (32-bit RISC-V with Soft-Float)
$ rustc \
2024-04-12 19:40:46 +08:00
+nightly \
-Z unstable-options \
--print target-spec-json \
--target riscv32i-unknown-none-elf
{
2024-04-16 23:55:48 +08:00
" arch" : " riscv32" ,
" atomic-cas" : false,
" cpu" : " generic-rv32" ,
2024-04-12 19:40:46 +08:00
" data-layout" : " e-m:e-p:32:32-i64:64-n32-S128" ,
2024-04-16 23:55:48 +08:00
" eh-frame-header" : false,
2024-04-12 19:40:46 +08:00
" emit-debug-gdb-scripts" : false,
2024-04-16 23:55:48 +08:00
" is-builtin" : true,
" linker" : " rust-lld" ,
" linker-flavor" : " ld.lld" ,
" llvm-target" : " riscv32" ,
" max-atomic-width" : 0,
" panic-strategy" : " abort" ,
" relocation-model" : " static" ,
2024-04-12 19:40:46 +08:00
" target-pointer-width" : " 32"
}
2024-04-16 23:55:48 +08:00
< / code > < / pre > < / div >
2024-04-18 23:36:42 +08:00
< p > That’ < a href = "https://gist.github.com/lupyuen/dd6a2ee58902e7925efd2a889bc0a833" > < strong > < code > riscv32i< / code > < / strong > < / a > : < strong > 32-bit< / strong > RISC-V with < strong > Soft-Float< / strong > .< / p >
< p > We do the same for < a href = "https://gist.github.com/lupyuen/9f269598bda11215832bd91a592d00a2" > < strong > < code > riscv64gc< / code > < / strong > < / a > : < strong > 64-bit< / strong > RISC-V with < strong > Double-Float< / strong > …< / p >
2024-04-17 22:56:36 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Dump the Built-In Rust Target:
2024-04-18 23:36:42 +08:00
## riscv64gc (64-bit RISC-V with Double-Float)
2024-04-12 19:40:46 +08:00
$ rustc \
+nightly \
-Z unstable-options \
--print target-spec-json \
--target riscv64gc-unknown-none-elf
{
2024-04-16 23:55:48 +08:00
" arch" : " riscv64" ,
" code-model" : " medium" ,
" cpu" : " generic-rv64" ,
2024-04-12 19:40:46 +08:00
" data-layout" : " e-m:e-p:64:64-i64:64-i128:128-n32:64-S128" ,
2024-04-16 23:55:48 +08:00
" eh-frame-header" : false,
2024-04-12 19:40:46 +08:00
" emit-debug-gdb-scripts" : false,
2024-04-16 23:55:48 +08:00
" features" : " +m,+a,+f,+d,+c" ,
" is-builtin" : true,
" linker" : " rust-lld" ,
2024-04-12 19:40:46 +08:00
" linker-flavor" : " ld.lld" ,
2024-04-16 23:55:48 +08:00
" llvm-abiname" : " lp64d" ,
" llvm-target" : " riscv64" ,
" max-atomic-width" : 64,
" panic-strategy" : " abort" ,
" relocation-model" : " static" ,
" supported-sanitizers" : [ " kernel-address" ],
2024-04-12 19:40:46 +08:00
" target-pointer-width" : " 64"
}
< / code > < / pre > < / div >
2024-04-20 00:07:45 +08:00
< p > Which has more goodies inside: features, llvm-abiname, …< / p >
2024-04-19 15:32:50 +08:00
< p > < em > We’ < / em > < / p >
2024-04-16 23:55:48 +08:00
< p > Exactly! Based on the above, we create our < strong > Rust Custom Target< / strong > : < a href = "https://github.com/lupyuen/nuttx-rust-app/blob/main/riscv32gc-unknown-none-elf.json" > < em > riscv32gc-unknown-none-elf.json< / em > < / a > < / p >
2024-04-12 19:40:46 +08:00
< div class = "example-wrap" > < pre class = "language-json" > < code > {
2024-04-16 23:55:48 +08:00
" arch" : " riscv32" ,
" cpu" : " generic-rv32" ,
2024-04-12 19:40:46 +08:00
" data-layout" : " e-m:e-p:32:32-i64:64-n32-S128" ,
2024-04-16 23:55:48 +08:00
" eh-frame-header" : false,
2024-04-12 19:40:46 +08:00
" emit-debug-gdb-scripts" : false,
2024-04-16 23:55:48 +08:00
" features" : " +m,+a,+f,+d,+c" ,
" linker" : " rust-lld" ,
2024-04-12 19:40:46 +08:00
" linker-flavor" : " ld.lld" ,
2024-04-16 23:55:48 +08:00
" llvm-abiname" : " ilp32d" ,
" llvm-target" : " riscv32" ,
" max-atomic-width" : 0,
" panic-strategy" : " abort" ,
" relocation-model" : " static" ,
2024-04-12 19:40:46 +08:00
" target-pointer-width" : " 32"
}
< / code > < / pre > < / div >
2024-04-18 23:36:42 +08:00
< p > Which is < a href = "https://gist.github.com/lupyuen/dd6a2ee58902e7925efd2a889bc0a833" > < strong > < code > riscv32i< / code > < / strong > < / a > plus these changes…< / p >
2024-04-12 19:40:46 +08:00
< ul >
< li >
2024-04-17 13:08:40 +08:00
< p > Remove < em > “is-builtin”: true< / em > < / p >
2024-04-17 22:56:36 +08:00
< p > (It’ < strong > Custom Target< / strong > , not Built-In)< / p >
2024-04-12 19:40:46 +08:00
< / li >
< li >
2024-04-17 13:08:40 +08:00
< p > Remove < em > “atomic-cas”: false< / em > < / p >
2024-04-18 14:50:16 +08:00
< p > < a href = "https://en.m.wikipedia.org/wiki/Compare-and-swap" > (Enable < strong > Atomic Compare-And-Swap< / strong > )< / a > < / p >
2024-04-12 19:40:46 +08:00
< / li >
< li >
2024-04-17 13:08:40 +08:00
< p > Add < em > “features”: “+m,+a,+f,+d,+c”< / em > < / p >
2024-04-19 12:39:45 +08:00
< p > < a href = "https://lupyuen.github.io/articles/rust4#software-vs-hardware-floating-point" > (Because we need < strong > IMAFDC< / strong > )< / a > < / p >
2024-04-12 19:40:46 +08:00
< / li >
< li >
2024-04-17 13:08:40 +08:00
< p > Add < em > “llvm-abiname”: “ilp32d”< / em > < / p >
2024-04-20 00:07:45 +08:00
< p > < a href = "https://lupyuen.github.io/articles/rust4#software-vs-hardware-floating-point" > (< strong > < code > ilp32d< / code > < / strong > comes from < strong > < code > make< / code > < code > --trace< / code > < / strong > )< / a > < / p >
2024-04-16 23:55:48 +08:00
< p > < a href = "https://lupyuen.github.io/articles/rust#custom-rust-target-for-bl602" > (More about < strong > < code > llvm-abiname< / code > < / strong > )< / a > < / p >
2024-04-12 19:40:46 +08:00
< / li >
< / ul >
2024-04-19 15:32:50 +08:00
< p > In Summary: We spliced Two Built-In Targets into Custom Target < strong > < code > riscv32gc< / code > < / strong > …< / p >
2024-04-17 10:28:26 +08:00
< span style = "font-size:80%" >
2024-04-18 23:36:42 +08:00
< div > < table > < thead > < tr > < th > < / th > < th style = "text-align: center" > < a href = "https://gist.github.com/lupyuen/dd6a2ee58902e7925efd2a889bc0a833" > riscv32i< / a > < br > < em > (Built-In)< / em > < / th > < th style = "text-align: center" > < a href = "https://gist.github.com/lupyuen/9f269598bda11215832bd91a592d00a2" > riscv64gc< / a > < br > < em > (Built-In)< / em > < / th > < th style = "text-align: center" > < a href = "https://github.com/lupyuen/nuttx-rust-app/blob/main/riscv32gc-unknown-none-elf.json" > riscv32gc< / a > < br > < em > (Custom)< / em > < / th > < / tr > < / thead > < tbody >
2024-04-17 08:49:53 +08:00
< tr > < td > < em > arch< / em > < / td > < td style = "text-align: center" > < strong > riscv32< / strong > < / td > < td style = "text-align: center" > riscv64< / td > < td style = "text-align: center" > < strong > riscv32< / strong > < / td > < / tr >
< tr > < td > < em > atomic-cas< / em > < / td > < td style = "text-align: center" > false< / td > < td style = "text-align: center" > < / td > < td style = "text-align: center" > < / td > < / tr >
< tr > < td > < em > cpu< / em > < / td > < td style = "text-align: center" > < strong > generic-rv32< / strong > < / td > < td style = "text-align: center" > generic-rv64< / td > < td style = "text-align: center" > < strong > generic-rv32< / strong > < / td > < / tr >
< tr > < td > < em > data-layout< / em > < / td > < td style = "text-align: center" > < strong > e-m:e-p:32…< / strong > < / td > < td style = "text-align: center" > e-m:e-p:64…< / td > < td style = "text-align: center" > < strong > e-m:e-p:32…< / strong > < / td > < / tr >
< tr > < td > < em > features< / em > < / td > < td style = "text-align: center" > < / td > < td style = "text-align: center" > < strong > +m,+a,+f,+d,+c< / strong > < / td > < td style = "text-align: center" > < strong > +m,+a,+f,+d,+c< / strong > < / td > < / tr >
< tr > < td > < em > is-builtin< / em > < / td > < td style = "text-align: center" > true< / td > < td style = "text-align: center" > true< / td > < td style = "text-align: center" > < / td > < / tr >
< tr > < td > < em > llvm-abiname< / em > < / td > < td style = "text-align: center" > < / td > < td style = "text-align: center" > lp64d< / td > < td style = "text-align: center" > ilp32d< / td > < / tr >
< tr > < td > < em > llvm-target< / em > < / td > < td style = "text-align: center" > < strong > riscv32< / strong > < / td > < td style = "text-align: center" > riscv64< / td > < td style = "text-align: center" > < strong > riscv32< / strong > < / td > < / tr >
< tr > < td > < em > max-atomic-width< / em > < / td > < td style = "text-align: center" > < / td > < td style = "text-align: center" > 64< / td > < td style = "text-align: center" > 0< / td > < / tr >
< tr > < td > < em > target-pointer-width< / em > < / td > < td style = "text-align: center" > < strong > 32< / strong > < / td > < td style = "text-align: center" > 64< / td > < td style = "text-align: center" > < strong > 32< / strong > < / td > < / tr >
2024-04-16 23:55:48 +08:00
< / tbody > < / table >
< / div > < / span >
2024-04-17 22:56:36 +08:00
< blockquote >
< p > < img src = "https://lupyuen.github.io/images/rust4-flow1b.jpg" alt = "Build the Rust Core Library" / > < / p >
< / blockquote >
2024-04-15 07:36:02 +08:00
< h1 id = "build-the-rust-core-library" > < a class = "doc-anchor" href = "#build-the-rust-core-library" > §< / a > 4 Build the Rust Core Library< / h1 >
2024-04-18 15:24:37 +08:00
< p > < em > Are we ready to rebuild with Double-Float?< / em > < / p >
< p > Not quite, we’ < strong > System Library< / strong > …< / p >
2024-04-17 13:51:00 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Rust Compiler fails to compile with our Custom Target `riscv32gc`
2024-04-17 13:33:17 +08:00
$ rustc \
2024-04-17 13:08:40 +08:00
--target riscv32gc-unknown-none-elf.json \
--edition 2021 \
--emit obj \
-g \
-C panic=abort \
-O \
hello_rust_main.rs \
-o hello_rust.o
2024-04-17 13:51:00 +08:00
## That' s because Rust Core Library for `riscv32gc` is missing
2024-04-17 13:08:40 +08:00
error[E0463]: can' t find crate for `core`
< / code > < / pre > < / div >
< p > Why? Remember…< / p >
2024-04-17 08:49:53 +08:00
< ul >
< li >
< p > < strong > GCC Compiler< / strong > supports Double-Float…< / p >
2024-04-18 15:24:37 +08:00
< p > Because it’ < strong > C Standard Library< / strong > for Double-Float< / p >
2024-04-17 08:49:53 +08:00
< / li >
< li >
2024-04-18 15:24:37 +08:00
< p > Thus < strong > Rust Compiler< / strong > will support Double-Float…< / p >
2024-04-18 23:36:42 +08:00
< p > Only when it has the < a href = "https://lupyuen.github.io/articles/rust3#standard-vs-embedded-rust" > < strong > Rust Core Library< / strong > < / a > for Double-Float< / p >
2024-04-17 08:49:53 +08:00
< / li >
< / ul >
2024-04-17 10:28:26 +08:00
< p > < em > And the Rust Core Library comes from?< / em > < / p >
< p > We call Rust Compiler to build the < strong > Rust Core Library< / strong > for Double-Float < strong > < code > riscv32gc< / code > < / strong > …< / p >
2024-04-17 13:08:40 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Download our Custom Target for `riscv32gc`
2024-04-18 18:55:16 +08:00
rm -f riscv32gc-unknown-none-elf.json
2024-04-17 13:08:40 +08:00
wget https://raw.githubusercontent.com/lupyuen/nuttx-rust-app/main/riscv32gc-unknown-none-elf.json
2024-04-17 10:28:26 +08:00
2024-07-23 11:07:45 +08:00
## Custom Target needs Nightly Build of Rust Compiler
rustup override set nightly
rustup component add rust-src --toolchain nightly
2024-04-17 10:28:26 +08:00
## Verify our Custom Target, make sure it' s OK
2024-04-12 19:40:46 +08:00
rustc \
--print cfg \
--target riscv32gc-unknown-none-elf.json
2024-04-17 17:19:16 +08:00
## `cargo build` requires a Rust Project, so we create an empty one.
2024-04-12 19:40:46 +08:00
## Ignore the error: `app already exists`
2024-07-23 11:07:45 +08:00
cargo new app || true
2024-04-17 10:28:26 +08:00
## Build the Rust Core Library for `riscv32gc`
2024-04-17 13:08:40 +08:00
## Include the `alloc` library, which will support Heap Memory in future.
2024-04-12 19:40:46 +08:00
## Ignore the error: `can' t find crate for std`
2024-07-23 11:07:45 +08:00
pushd app
2024-04-12 19:40:46 +08:00
cargo build \
-Zbuild-std=core,alloc \
2024-07-23 11:07:45 +08:00
--target ../riscv32gc-unknown-none-elf.json \
|| true
2024-04-12 19:40:46 +08:00
popd
< / code > < / pre > < / div >
2024-07-23 11:07:45 +08:00
< p > < a href = "https://lupyuen.github.io/articles/rust4#appendix-build-nuttx-for-qemu" > (See the < strong > Build Script< / strong > )< / a > < / p >
2024-04-17 13:08:40 +08:00
< p > < strong > Rust Core Library< / strong > for Double-Float < strong > < code > riscv32gc< / code > < / strong > is done!< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Show the Rust Core Library for `riscv32gc`
$ ls app/target/riscv32gc-unknown-none-elf/debug/deps
alloc-254848389e7e2c53.d
app-cf88b81a5fca23b3.d
compiler_builtins-d5922d64507adf16.d
core-ec2ec78e26b8c830.d
liballoc-254848389e7e2c53.rlib
liballoc-254848389e7e2c53.rmeta
libcompiler_builtins-d5922d64507adf16.rlib
libcompiler_builtins-d5922d64507adf16.rmeta
libcore-ec2ec78e26b8c830.rlib
libcore-ec2ec78e26b8c830.rmeta
librustc_std_workspace_core-3cc5bcc9f701a6e7.rlib
librustc_std_workspace_core-3cc5bcc9f701a6e7.rmeta
rustc_std_workspace_core-3cc5bcc9f701a6e7.d
< / code > < / pre > < / div >
2024-04-18 15:24:37 +08:00
< p > Now we < strong > rebuild our Rust App< / strong > with the Custom Target (linked to our Rust Core Library)…< / p >
2024-04-17 18:55:50 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Compile our Rust App with Rust Core Library for `riscv32gc`
2024-04-17 13:08:40 +08:00
## We changed the Target to `riscv32gc-unknown-none-elf.json`
## TODO: Change `../apps` to the NuttX Apps Folder
2024-04-12 19:40:46 +08:00
rustc \
2024-04-16 23:00:41 +08:00
--target riscv32gc-unknown-none-elf.json \
2024-04-12 19:40:46 +08:00
--edition 2021 \
--emit obj \
-g \
-C panic=abort \
-O \
../apps/examples/hello_rust/hello_rust_main.rs \
-o ../apps/examples/hello_rust/*hello_rust.o \
\
-C incremental=app/target/riscv32gc-unknown-none-elf/debug/incremental \
-L dependency=app/target/riscv32gc-unknown-none-elf/debug/deps \
-L dependency=app/target/debug/deps \
--extern noprelude:alloc=`ls app/target/riscv32gc-unknown-none-elf/debug/deps/liballoc-*.rlib` \
--extern noprelude:compiler_builtins=`ls app/target/riscv32gc-unknown-none-elf/debug/deps/libcompiler_builtins-*.rlib` \
--extern noprelude:core=`ls app/target/riscv32gc-unknown-none-elf/debug/deps/libcore-*.rlib` \
-Z unstable-options
2024-04-17 13:08:40 +08:00
< / code > < / pre > < / div >
2024-07-23 11:07:45 +08:00
< p > < a href = "https://lupyuen.github.io/articles/rust4#appendix-build-nuttx-for-qemu" > (See the < strong > Build Script< / strong > )< / a > < / p >
2024-04-17 13:28:53 +08:00
< p > (We’ < / p >
< p > < em > Are we Double-Floating yet?< / em > < / p >
2024-04-18 15:24:37 +08:00
< p > Yep we have a < strong > Yummy Double-Float< / strong > with 2 scoops of ice cream…< / p >
2024-04-17 13:28:53 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Dump the ELF Header of our Compiled Rust App
2024-04-17 13:08:40 +08:00
## TODO: Change `../apps` to the NuttX Apps Folder
2024-04-17 13:28:53 +08:00
$ riscv64-unknown-elf-readelf \
2024-04-15 10:45:47 +08:00
--file-header --arch-specific \
2024-04-12 19:40:46 +08:00
../apps/examples/hello_rust/*hello_rust.o
2024-04-17 13:28:53 +08:00
## We have Double-Float `riscv32gc` yay!
Flags: 0x5, RVC, double-float ABI
2024-04-17 13:08:40 +08:00
< / code > < / pre > < / div >
2024-04-18 00:38:42 +08:00
< p > < a href = "https://gist.github.com/lupyuen/e7cdef603bdb16fbc82c2bf940b5d2d8" > (See the < strong > ELF Header< / strong > )< / a > < / p >
2024-04-18 11:31:42 +08:00
< p > < em > How did we get the Rust Compiler Options?< / em > < / p >
2024-04-19 15:37:50 +08:00
< p > We copied the above options from < strong > < code > cargo< / code > < code > build< / code > < code > -v< / code > < / strong > …< / p >
2024-04-18 11:31:42 +08:00
< ul >
2024-04-19 12:39:45 +08:00
< li > < a href = "https://lupyuen.github.io/articles/rust4#appendix-rust-compiler-options" > < strong > “Rust Compiler Options”< / strong > < / a > < / li >
2024-04-18 11:31:42 +08:00
< / ul >
2024-04-18 10:21:21 +08:00
< p > < em > rustc vs cargo build: What’ < / em > < / p >
< ul >
< li >
< p > < strong > < code > rustc< / code > < / strong > is the Rust Compiler that compiles Rust Programs to Rust Binaries< / p >
< p > (Works like GCC Compiler)< / p >
< / li >
< li >
2024-04-19 15:37:50 +08:00
< p > < strong > < code > cargo< / code > < code > build< / code > < / strong > wraps around < strong > < code > rustc< / code > < / strong > for Multi-Step Builds< / p >
2024-04-18 23:36:42 +08:00
< p > < a href = "https://lupyuen.github.io/articles/rust3#standard-vs-embedded-rust" > (Like for < strong > Rust Core Library< / strong > )< / a > < / p >
2024-04-18 10:21:21 +08:00
< / li >
< / ul >
2024-04-19 12:39:45 +08:00
< p > We could have called < strong > < code > rustc< / code > < / strong > for building the Rust Core Library. But it will be a bunch of steps with < a href = "https://lupyuen.github.io/articles/rust4#appendix-rust-compiler-options" > < strong > many many options< / strong > < / a > .< / p >
2024-04-17 17:19:16 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-flow.jpg" alt = "NuttX Links OK with Rust" / > < / p >
< h1 id = "nuttx-links-ok-with-rust" > < a class = "doc-anchor" href = "#nuttx-links-ok-with-rust" > §< / a > 5 NuttX Links OK with Rust< / h1 >
2024-04-18 14:50:16 +08:00
< p > < em > We compiled our Rust App with Double-Float riscv32gc…< / em > < / p >
2024-04-17 17:19:16 +08:00
< p > < em > Is our NuttX Build hunky dory now?< / em > < / p >
2024-04-17 18:55:50 +08:00
< p > Yep < strong > NuttX builds OK now< / strong > ! GCC Compiler and Rust Compiler are harmonised to Double-Float…< / p >
2024-04-17 17:19:16 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Copy the Rust Binary that will be linked with NuttX
## TODO: Change `../apps` to the NuttX Apps Folder
cp \
../apps/examples/hello_rust/*hello_rust.o \
../apps/examples/hello_rust/*hello_rust_1.o
## NuttX should link correctly now.
## TODO: Change `../nuttx` to the NuttX Kernel Folder
pushd ../nuttx
make
popd
< / code > < / pre > < / div >
2024-07-23 11:07:45 +08:00
< p > < a href = "https://lupyuen.github.io/articles/rust4#appendix-build-nuttx-for-qemu" > (See the < strong > Build Script< / strong > )< / a > < / p >
2024-04-17 17:19:16 +08:00
< p > We boot < strong > NuttX in QEMU Emulator< / strong > for 32-bit RISC-V…< / p >
2024-04-19 15:32:50 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## For macOS:
brew install qemu
## For Debian and Ubuntu:
sudo apt install qemu-system-riscv32
## Boot NuttX in QEMU RISC-V (32-bit)
2024-04-17 17:19:16 +08:00
## TODO: Change `../nuttx` to the NuttX Kernel Folder
pushd ../nuttx
qemu-system-riscv32 \
-semihosting \
-M virt,aclint=on \
-cpu rv32 \
-bios none \
-kernel nuttx \
-nographic
popd
< / code > < / pre > < / div >
< p > Our < strong > Rust App< / strong > works wonderfully on NuttX! (Pic below)< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > NuttShell (NSH) NuttX-12.4.0-RC0
nsh> hello_rust
Hello, Rust!!
## Exit QEMU: Press `Ctrl-A` then `x`
< / code > < / pre > < / div >
< p > < a href = "https://gist.github.com/lupyuen/31c78de72ade71bbdf63372b44749cd4#file-rust-on-nuttx-build-log-L356-L384" > (See the < strong > NuttX Log< / strong > )< / a > < / p >
2024-04-18 17:04:05 +08:00
< p > < em > Phew so much work to build a tiny Rust App?< / em > < / p >
2024-04-17 17:44:28 +08:00
< p > Yeah. And integrating this into the < strong > NuttX Makefiles< / strong > will be challenging.< / p >
2024-04-18 23:36:42 +08:00
< p > (How would < a href = "https://rust-for-linux.com/" > < strong > Linux Kernel< / strong > < / a > handle Custom Rust Targets?)< / p >
2024-04-20 09:24:36 +08:00
< p > < a href = "https://github.com/rust-lang/rust/issues/65024" > (More about < strong > Hard-Float Targets< / strong > in RISC-V)< / a > < / p >
2024-04-17 17:19:16 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-title.jpg" alt = "Rust Apps on Apache NuttX RTOS and QEMU RISC-V" / > < / p >
2024-04-15 07:36:02 +08:00
< h1 id = "rust-build-for-64-bit-risc-v" > < a class = "doc-anchor" href = "#rust-build-for-64-bit-risc-v" > §< / a > 6 Rust Build for 64-bit RISC-V< / h1 >
2024-04-19 15:32:50 +08:00
< p > From 32-bit to 64-bit: We tried compiling our Rust App for < strong > 64-bit RISC-V QEMU< / strong > …< / p >
2024-04-18 14:50:16 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Build NuttX for QEMU RISC-V 64-bit
$ tools/configure.sh rv-virt:nsh64
2024-04-15 07:36:02 +08:00
$ make menuconfig
## TODO: Enable " Hello Rust Example"
$ make
RUSTC: hello_rust_main.rs error: Error loading target specification:
Could not find specification for target " riscv64i-unknown-none-elf" .
Run `rustc --print target-list` for a list of built-in targets
< / code > < / pre > < / div >
2024-04-18 14:50:16 +08:00
< p > But Rust Compiler says that < strong > < code > riscv64i< / code > < / strong > isn’ < / p >
< p > < strong > Exercise for the Reader:< / strong > < / p >
< ol >
< li >
< p > Is < strong > < code > riscv64i< / code > < / strong > the correct target for QEMU?< / p >
2024-04-19 12:39:45 +08:00
< p > < a href = "https://www.qemu.org/docs/master/system/riscv/virt.html#supported-devices" > (< strong > Hint:< / strong > See this)< / a > < / p >
2024-04-18 14:50:16 +08:00
< p > < em > [10 points]< / em > < / p >
2024-04-18 17:04:05 +08:00
< hr >
2024-04-18 14:50:16 +08:00
< / li >
< li >
< p > How should we < strong > Fix the Build< / strong > ?< / p >
< p > < em > [10 points]< / em > < / p >
2024-04-18 17:04:05 +08:00
< hr >
2024-04-18 14:50:16 +08:00
< / li >
< li >
< p > Do we need a < strong > Custom Target< / strong > ?< / p >
< p > (< strong > Hint:< / strong > Answer is printed in this article somewhere)< / p >
< p > < em > [10 points]< / em > < / p >
2024-04-18 17:04:05 +08:00
< hr >
2024-04-18 14:50:16 +08:00
< / li >
< li >
2024-04-18 23:36:42 +08:00
< p > Will it run on < a href = "https://www.hackster.io/lupyuen/8-risc-v-sbc-on-a-real-time-operating-system-ox64-nuttx-474358" > < strong > Ox64 BL808 SBC< / strong > < / a > ?< / p >
2024-04-18 14:50:16 +08:00
< p > < em > [10 points]< / em > < / p >
2024-04-18 17:04:05 +08:00
< hr >
2024-04-18 14:50:16 +08:00
< / li >
< / ol >
2024-04-18 17:06:07 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-flow.jpg" alt = "NuttX Links OK with Rust" / > < / p >
2024-04-15 07:36:02 +08:00
< h1 id = "whats-next" > < a class = "doc-anchor" href = "#whats-next" > §< / a > 7 What’ < / h1 >
2024-04-20 00:07:45 +08:00
< p > Today we learnt a bit more about < strong > C-to-Rust Interop< / strong > (pic above)…< / p >
< ul >
< li >
2024-04-20 09:22:20 +08:00
< p > NuttX failed to link our Rust App because Rust compiles for < strong > Soft-Float< / strong > , NuttX expects < strong > Double-Float< / strong > < / p >
2024-04-20 00:07:45 +08:00
< p > (Software vs Hardware Floating-Point)< / p >
< / li >
< li >
2024-04-20 09:22:20 +08:00
< p > But Rust < strong > doesn’ < / strong > < / p >
< p > (Built-In Target doesn’ < / p >
2024-04-20 00:07:45 +08:00
< / li >
< li >
2024-04-20 09:22:20 +08:00
< p > So we created a < strong > Rust Custom Target< / strong > for Double-Float: RISCV32GC< / p >
< p > (By mashing up RISCV32I and RISCV64GC)< / p >
2024-04-20 00:07:45 +08:00
< / li >
< li >
2024-04-20 09:22:20 +08:00
< p > We rebuilt the < strong > Rust Core Library< / strong > for Double-Float< / p >
< p > (With < strong > < code > cargo< / code > < code > build< / code > < / strong > )< / p >
2024-04-20 00:07:45 +08:00
< / li >
< li >
2024-04-20 09:22:20 +08:00
< p > And our Rust App < strong > builds OK with NuttX< / strong > < / p >
< p > (Runs perfectly on QEMU Emulator for RISC-V)< / p >
2024-04-20 00:07:45 +08:00
< / li >
< / ul >
2024-04-15 07:36:02 +08:00
< p > Many Thanks to my < a href = "https://github.com/sponsors/lupyuen" > < strong > GitHub Sponsors< / strong > < / a > (and the awesome NuttX Community) for supporting my work! This article wouldn’ < / p >
< ul >
< li >
< p > < a href = "https://github.com/sponsors/lupyuen" > < strong > Sponsor me a coffee< / strong > < / a > < / p >
< / li >
< li >
2024-04-21 06:36:48 +08:00
< p > < a href = "https://news.ycombinator.com/item?id=40101628" > < strong > Discuss this article on Hacker News< / strong > < / a > < / p >
< / li >
< li >
2024-04-15 07:36:02 +08:00
< p > < a href = "https://github.com/lupyuen/nuttx-ox64" > < strong > My Current Project: “Apache NuttX RTOS for Ox64 BL808”< / strong > < / a > < / p >
< / li >
< li >
< p > < a href = "https://github.com/lupyuen/nuttx-star64" > < strong > My Other Project: “NuttX for Star64 JH7110”< / strong > < / a > < / p >
< / li >
< li >
< p > < a href = "https://github.com/lupyuen/pinephone-nuttx" > < strong > Older Project: “NuttX for PinePhone”< / strong > < / a > < / p >
< / li >
< li >
< p > < a href = "https://lupyuen.github.io" > < strong > Check out my articles< / strong > < / a > < / p >
< / li >
< li >
< p > < a href = "https://lupyuen.github.io/rss.xml" > < strong > RSS Feed< / strong > < / a > < / p >
< / li >
< / ul >
< p > < em > Got a question, comment or suggestion? Create an Issue or submit a Pull Request here…< / em > < / p >
< p > < a href = "https://github.com/lupyuen/lupyuen.github.io/blob/master/src/rust4.md" > < strong > lupyuen.github.io/src/rust4.md< / strong > < / a > < / p >
2024-07-23 10:59:58 +08:00
< p > < img src = "https://lupyuen.github.io/images/rust4-flow.jpg" alt = "Build NuttX for QEMU with Rust App" / > < / p >
< h1 id = "appendix-build-nuttx-for-qemu" > < a class = "doc-anchor" href = "#appendix-build-nuttx-for-qemu" > §< / a > 8 Appendix: Build NuttX for QEMU< / h1 >
< p > Follow these steps to build < strong > NuttX for QEMU Emulator< / strong > (32-bit RISC-V) bundled with our < strong > Rust App< / strong > (pic above)…< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > #!/usr/bin/env bash
# Build NuttX for QEMU RISC-V 32-bit with Rust App
## TODO: Set PATH
export PATH=" $HOME/xpack-riscv-none-elf-gcc-13.2.0-2/bin:$PATH"
set -e # Exit when any command fails
set -x # Echo commands
## Build NuttX
function build_nuttx {
## Go to NuttX Folder
pushd ../nuttx
## Build NuttX
make -j 8
## Return to previous folder
popd
}
## Build Rust App for QEMU RISC-V 32-bit with Rust Custom Target
function build_rust_riscv32 {
## Go to NuttX Folder
pushd ../nuttx
## Download our Custom Target for `riscv32gc`
rm -f riscv32gc-unknown-none-elf.json
wget https://raw.githubusercontent.com/lupyuen/nuttx-rust-app/main/riscv32gc-unknown-none-elf.json
## Custom Target needs Nightly Build of Rust Compiler
rustup override set nightly
rustup component add rust-src --toolchain nightly
## Verify our Custom Target, make sure it' s OK
rustc \
--print cfg \
--target riscv32gc-unknown-none-elf.json
## `cargo build` requires a Rust Project, so we create an empty one.
## Ignore the error: `app already exists`
cargo new app || true
## Build the Rust Core Library for `riscv32gc`
## Include the `alloc` library, which will support Heap Memory in future.
## Ignore the error: `can' t find crate for std`
pushd app
cargo build \
-Zbuild-std=core,alloc \
--target ../riscv32gc-unknown-none-elf.json \
|| true
popd
## Compile our Rust App with Rust Core Library for `riscv32gc`
## We changed the Target to `riscv32gc-unknown-none-elf.json`
rustc \
--target riscv32gc-unknown-none-elf.json \
--edition 2021 \
--emit obj \
-g \
-C panic=abort \
-O \
../apps/examples/hello_rust/hello_rust_main.rs \
-o ../apps/examples/hello_rust/*hello_rust.o \
\
-C incremental=app/target/riscv32gc-unknown-none-elf/debug/incremental \
-L dependency=app/target/riscv32gc-unknown-none-elf/debug/deps \
-L dependency=app/target/debug/deps \
--extern noprelude:alloc=`ls app/target/riscv32gc-unknown-none-elf/debug/deps/liballoc-*.rlib` \
--extern noprelude:compiler_builtins=`ls app/target/riscv32gc-unknown-none-elf/debug/deps/libcompiler_builtins-*.rlib` \
--extern noprelude:core=`ls app/target/riscv32gc-unknown-none-elf/debug/deps/libcore-*.rlib` \
-Z unstable-options
## NuttX Build need us to copy hello_rust.o to hello_rust_1.o
cp \
../apps/examples/hello_rust/*hello_rust.o \
../apps/examples/hello_rust/*hello_rust_1.o
## Return to previous folder
popd
}
2024-07-23 11:07:45 +08:00
## Configure the NuttX Build
make distclean
tools/configure.sh rv-virt:nsh
2024-07-23 10:59:58 +08:00
2024-07-23 11:07:45 +08:00
## Enable the Hello Rust App
2024-07-23 10:59:58 +08:00
kconfig-tweak --enable CONFIG_EXAMPLES_HELLO_RUST
## Update the Kconfig Dependencies
make olddefconfig
2024-07-23 12:14:42 +08:00
## Build NuttX. Ignore the error: `can' t link soft-float modules with double-float modules`
2024-07-23 10:59:58 +08:00
build_nuttx || true
2024-07-23 12:14:42 +08:00
## Build the Rust App with Custom Target
2024-07-23 10:59:58 +08:00
build_rust_riscv32
2024-07-23 12:14:42 +08:00
## Link the Rust App with NuttX
2024-07-23 10:59:58 +08:00
build_nuttx
## Show the size
riscv-none-elf-size nuttx
## Export the Binary Image to nuttx.bin
riscv-none-elf-objcopy \
-O binary \
nuttx \
nuttx.bin
## Copy the config
cp .config nuttx.config
## Dump the NuttX Kernel Disassembly to nuttx.S
riscv-none-elf-objdump \
--syms --source --reloc --demangle --line-numbers --wide \
--debugging \
nuttx \
> nuttx.S \
2> & 1
## Dump the Rust App Disassembly to hello_rust_1.S
riscv-none-elf-objdump \
--syms --source --reloc --demangle --line-numbers --wide \
--debugging \
../apps/examples/hello_rust/*1.o \
> hello_rust_1.S \
2> & 1
## Start the emulator
qemu-system-riscv32 \
-semihosting \
-M virt,aclint=on \
-cpu rv32 \
-kernel nuttx \
-nographic \
2024-07-23 11:11:57 +08:00
-bios none
2024-07-23 10:59:58 +08:00
< / code > < / pre > < / div >
< p > < a href = "https://gist.github.com/lupyuen/69da35a027cf780680944010b4a85fe7" > (See the < strong > Build Script< / strong > )< / a > < / p >
2024-04-17 23:16:58 +08:00
< blockquote >
< p > < img src = "https://lupyuen.github.io/images/rust4-flow1b.jpg" alt = "Building our Rust App" / > < / p >
< / blockquote >
2024-07-23 10:59:58 +08:00
< h1 id = "appendix-rust-compiler-options" > < a class = "doc-anchor" href = "#appendix-rust-compiler-options" > §< / a > 9 Appendix: Rust Compiler Options< / h1 >
2024-04-18 10:21:21 +08:00
< p > < em > How did we get the Rust Compiler Options for riscv32gc?< / em > < / p >
< p > Earlier we compiled our Rust App with Rust Core Library for < strong > < code > riscv32gc< / code > < / strong > …< / p >
< ul >
2024-04-19 12:39:45 +08:00
< li > < a href = "https://lupyuen.github.io/articles/rust4#build-the-rust-core-library" > < strong > “Build the Rust Core Library”< / strong > < / a > < / li >
2024-04-18 10:21:21 +08:00
< / ul >
< p > And we saw these < strong > Rust Compiler Options< / strong > …< / p >
2024-04-17 18:55:50 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Compile our Rust App with Rust Core Library for `riscv32gc`
## We changed the Target to `riscv32gc-unknown-none-elf.json`
## TODO: Change `../apps` to the NuttX Apps Folder
rustc \
--target riscv32gc-unknown-none-elf.json \
--edition 2021 \
--emit obj \
-g \
-C panic=abort \
-O \
../apps/examples/hello_rust/hello_rust_main.rs \
-o ../apps/examples/hello_rust/*hello_rust.o \
\
-C incremental=app/target/riscv32gc-unknown-none-elf/debug/incremental \
-L dependency=app/target/riscv32gc-unknown-none-elf/debug/deps \
-L dependency=app/target/debug/deps \
--extern noprelude:alloc=`ls app/target/riscv32gc-unknown-none-elf/debug/deps/liballoc-*.rlib` \
--extern noprelude:compiler_builtins=`ls app/target/riscv32gc-unknown-none-elf/debug/deps/libcompiler_builtins-*.rlib` \
--extern noprelude:core=`ls app/target/riscv32gc-unknown-none-elf/debug/deps/libcore-*.rlib` \
-Z unstable-options
< / code > < / pre > < / div >
2024-04-19 15:37:50 +08:00
< p > The above options were copied from < strong > < code > cargo< / code > < code > build< / code > < code > -v< / code > < / strong > , here’ < / p >
< p > Remember we ran < a href = "https://lupyuen.github.io/articles/rust4#build-the-rust-core-library" > < strong > < code > cargo< / code > < code > build< / code > < / strong > < / a > to compile the < a href = "https://lupyuen.github.io/articles/rust3#standard-vs-embedded-rust" > < strong > Rust Core Library< / strong > < / a > ?< / p >
2024-04-18 18:55:16 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Download our Custom Target for `riscv32gc`
rm -f riscv32gc-unknown-none-elf.json
wget https://raw.githubusercontent.com/lupyuen/nuttx-rust-app/main/riscv32gc-unknown-none-elf.json
2024-07-23 11:11:57 +08:00
## Custom Target needs Nightly Build of Rust Compiler
rustup override set nightly
rustup component add rust-src --toolchain nightly
2024-04-18 18:55:16 +08:00
## Verify our Custom Target, make sure it' s OK
rustc \
--print cfg \
--target riscv32gc-unknown-none-elf.json
## `cargo build` requires a Rust Project, so we create an empty one.
## Ignore the error: `app already exists`
2024-07-23 11:11:57 +08:00
cargo new app || true
2024-04-18 18:55:16 +08:00
## Build the Rust Core Library for `riscv32gc`
## Include the `alloc` library, which will support Heap Memory in future.
## Ignore the error: `can' t find crate for std`
2024-07-23 11:11:57 +08:00
pushd app
2024-04-18 18:55:16 +08:00
cargo build \
2024-04-17 18:55:50 +08:00
-Zbuild-std=core,alloc \
2024-07-23 11:11:57 +08:00
--target ../riscv32gc-unknown-none-elf.json \
|| true
2024-04-18 18:55:16 +08:00
popd
2024-04-17 18:55:50 +08:00
< / code > < / pre > < / div >
2024-04-18 18:55:16 +08:00
< ul >
< li >
2024-04-19 15:37:50 +08:00
< p > < strong > < code > cargo< / code > < code > build< / code > < / strong > will call < strong > < code > rustc< / code > < / strong > with a whole bunch of options.< / p >
2024-04-18 18:55:16 +08:00
< / li >
< li >
2024-04-19 15:37:50 +08:00
< p > We switched it to < strong > < code > cargo< / code > < code > build< / code > < code > -v< / code > < / strong > , which will dump the < strong > < code > rustc< / code > < / strong > options.< / p >
2024-04-18 18:55:16 +08:00
< / li >
< li >
2024-04-17 18:55:50 +08:00
< p > Hence we see the options that will compile a Rust App with our Rust Core Library for < strong > < code > riscv32gc< / code > < / strong > …< / p >
2024-04-17 22:56:36 +08:00
< p > (TODO: Will these options change in future versions of < strong > < code > cargo< / code > < / strong > ?)< / p >
2024-04-18 18:55:16 +08:00
< / li >
< / ul >
2024-04-17 18:55:50 +08:00
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Build the Rust Core Library for `riscv32gc`
## And the Empty Rust Project for `riscv32gc`
## `-v` will dump the `rustc` options
$ cargo build -v \
2024-04-12 19:40:46 +08:00
-Zbuild-std=core,alloc \
--target ../riscv32gc-unknown-none-elf.json
Compiling compiler_builtins v0.1.101
Compiling core v0.0.0 ($HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core)
2024-04-17 18:55:50 +08:00
## Generate the Rust Build Script for `riscv32gc`
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc
--crate-name build_script_build
2024-04-17 22:56:36 +08:00
--edition=2018
$HOME/.cargo/registry/src/index.crates.io-6f17d22bba15001f/compiler_builtins-0.1.101/build.rs
2024-04-17 18:55:50 +08:00
--error-format=json
--json=diagnostic-rendered-ansi,artifacts,future-incompat
--diagnostic-width=94
--crate-type bin
--emit=dep-info,link
-C embed-bitcode=no
-C debuginfo=2
-C split-debuginfo=unpacked
--cfg ' feature=" compiler-builtins" '
--cfg ' feature=" core" '
--cfg ' feature=" default" '
--cfg ' feature=" rustc-dep-of-std" '
-C metadata=9bd0bac7535b33a8
-C extra-filename=-9bd0bac7535b33a8
--out-dir $HOME/riscv/nuttx-rust-app/app/target/debug/build/compiler_builtins-9bd0bac7535b33a8
-Z force-unstable-if-unmarked
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/debug/deps
--cap-lints allow`
## Build the Rust Core Library for `riscv32gc`
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc
--crate-name core
2024-04-17 22:56:36 +08:00
--edition=2021
$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/lib.rs
2024-04-17 18:55:50 +08:00
--error-format=json
--json=diagnostic-rendered-ansi,artifacts,future-incompat
--diagnostic-width=94
--crate-type lib
--emit=dep-info,metadata,link
-C embed-bitcode=no
-C debuginfo=2
-C metadata=d271c6ebb87f9b41
-C extra-filename=-d271c6ebb87f9b41
--out-dir $HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
--target $HOME/riscv/nuttx-rust-app/riscv32gc-unknown-none-elf.json
-Z force-unstable-if-unmarked
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/debug/deps
--cap-lints allow`
2024-04-12 19:40:46 +08:00
Running `$HOME/riscv/nuttx-rust-app/app/target/debug/build/compiler_builtins-9bd0bac7535b33a8/build-script-build`
2024-04-17 18:55:50 +08:00
2024-04-12 19:40:46 +08:00
Compiling rustc-std-workspace-core v1.99.0 ($HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/rustc-std-workspace-core)
2024-04-17 18:55:50 +08:00
## Build the Rust Workspace Core for `riscv32gc`
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc
--crate-name rustc_std_workspace_core
2024-04-17 22:56:36 +08:00
--edition=2021
$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/rustc-std-workspace-core/lib.rs
2024-04-17 18:55:50 +08:00
--error-format=json
--json=diagnostic-rendered-ansi,artifacts,future-incompat
--diagnostic-width=94
--crate-type lib
--emit=dep-info,metadata,link
-C embed-bitcode=no
-C debuginfo=2
-C metadata=52e0df2b2cc19b6e
-C extra-filename=-52e0df2b2cc19b6e
--out-dir $HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
--target $HOME/riscv/nuttx-rust-app/riscv32gc-unknown-none-elf.json
-Z force-unstable-if-unmarked
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/debug/deps
--extern core=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/libcore-d271c6ebb87f9b41.rmeta
--cap-lints allow`
## Build the Rust Compiler Builtins for `riscv32gc`
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc
--crate-name compiler_builtins
2024-04-17 22:56:36 +08:00
--edition=2018
$HOME/.cargo/registry/src/index.crates.io-6f17d22bba15001f/compiler_builtins-0.1.101/src/lib.rs
2024-04-17 18:55:50 +08:00
--error-format=json
--json=diagnostic-rendered-ansi,artifacts,future-incompat
--diagnostic-width=94
--crate-type lib
--emit=dep-info,metadata,link
-C embed-bitcode=no
-C debuginfo=2
--cfg ' feature=" compiler-builtins" '
--cfg ' feature=" core" '
--cfg ' feature=" default" '
--cfg ' feature=" rustc-dep-of-std" '
-C metadata=cd0d33c2bd30ca51
-C extra-filename=-cd0d33c2bd30ca51
--out-dir $HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
--target $HOME/riscv/nuttx-rust-app/riscv32gc-unknown-none-elf.json
-Z force-unstable-if-unmarked
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/debug/deps
--extern core=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/librustc_std_workspace_core-52e0df2b2cc19b6e.rmeta
--cap-lints allow
--cfg ' feature=" unstable" '
--cfg ' feature=" mem" ' `
2024-04-12 19:40:46 +08:00
Compiling alloc v0.0.0 ($HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc)
2024-04-17 18:55:50 +08:00
## Build the Rust Alloc Library for `riscv32gc`
## Which will support Heap Memory in future
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc
--crate-name alloc
2024-04-17 22:56:36 +08:00
--edition=2021
$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/lib.rs
2024-04-17 18:55:50 +08:00
--error-format=json
--json=diagnostic-rendered-ansi,artifacts,future-incompat
--diagnostic-width=94
--crate-type lib
--emit=dep-info,metadata,link
-C embed-bitcode=no
-C debuginfo=2
-C metadata=5d7bc2e4f3c29e08
-C extra-filename=-5d7bc2e4f3c29e08
--out-dir $HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
--target $HOME/riscv/nuttx-rust-app/riscv32gc-unknown-none-elf.json
-Z force-unstable-if-unmarked
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/debug/deps
--extern compiler_builtins=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/libcompiler_builtins-cd0d33c2bd30ca51.rmeta
--extern core=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/libcore-d271c6ebb87f9b41.rmeta
--cap-lints allow`
2024-04-12 19:40:46 +08:00
Compiling app v0.1.0 ($HOME/riscv/nuttx-rust-app/app)
2024-04-17 18:55:50 +08:00
## Compile our Empty Rust Project with Rust Core Library for `riscv32gc`
2024-04-19 15:32:50 +08:00
## These are the options that we copied into NuttX Build...
2024-04-17 18:55:50 +08:00
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc
--crate-name app
2024-04-17 22:56:36 +08:00
--edition=2021
src/main.rs
2024-04-17 18:55:50 +08:00
--error-format=json
--json=diagnostic-rendered-ansi,artifacts,future-incompat
--diagnostic-width=94
--crate-type bin
--emit=dep-info,link
-C embed-bitcode=no
-C debuginfo=2
-C metadata=1ff442e6481e1397
-C extra-filename=-1ff442e6481e1397
--out-dir $HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
--target $HOME/riscv/nuttx-rust-app/riscv32gc-unknown-none-elf.json
-C incremental=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/incremental
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps
-L dependency=$HOME/riscv/nuttx-rust-app/app/target/debug/deps
--extern ' noprelude:alloc=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/liballoc-5d7bc2e4f3c29e08.rlib'
--extern ' noprelude:compiler_builtins=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/libcompiler_builtins-cd0d33c2bd30ca51.rlib'
--extern ' noprelude:core=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/libcore-d271c6ebb87f9b41.rlib'
-Z unstable-options`
## Ignore this error. Rust Standard Library and `println` won' t work for `riscv32gc`
2024-04-12 19:40:46 +08:00
error[E0463]: can' t find crate for `std`
|
= note: the `riscv32gc-unknown-none-elf` target may not support the standard library
= note: `std` is required by `app` because it does not declare `#![no_std]`
= help: consider building the standard library from source with `cargo build -Zbuild-std`
error: cannot find macro `println` in this scope
--> src/main.rs:2:5
|
2 | println!(" Hello, world!" );
| ^^^^^^^
error: `#[panic_handler]` function required, but not found
For more information about this error, try `rustc --explain E0463`.
error: could not compile `app` (bin " app" ) due to 3 previous errors
Caused by:
process didn' t exit successfully: `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc --crate-name app --edition=2021 src/main.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=94 --crate-type bin --emit=dep-info,link -C embed-bitcode=no -C debuginfo=2 -C metadata=1ff442e6481e1397 -C extra-filename=-1ff442e6481e1397 --out-dir $HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps --target $HOME/riscv/nuttx-rust-app/riscv32gc-unknown-none-elf.json -C incremental=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/incremental -L dependency=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps -L dependency=$HOME/riscv/nuttx-rust-app/app/target/debug/deps --extern ' noprelude:alloc=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/liballoc-5d7bc2e4f3c29e08.rlib' --extern ' noprelude:compiler_builtins=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/libcompiler_builtins-cd0d33c2bd30ca51.rlib' --extern ' noprelude:core=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/libcore-d271c6ebb87f9b41.rlib' -Z unstable-options` (exit status: 1)
< / code > < / pre > < / div >
2024-04-12 19:18:02 +08:00
<!-- Begin scripts/rustdoc - after.html: Post - HTML for Custom Markdown files processed by rustdoc, like chip8.md -->
<!-- Begin Theme Picker and Prism Theme -->
< script src = "../theme.js" > < / script >
< script src = "../prism.js" > < / script >
<!-- Theme Picker and Prism Theme -->
<!-- End scripts/rustdoc - after.html -->
< / body >
< / html >
