2024-04-12 19:18:02 +08:00
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< 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 >
< li > < a href = "#appendix-rust-compiler-options" > 8 Appendix: Rust Compiler Options< / a > < ul > < / ul > < / li > < / ul > < / nav > < p > 📝 < em > 22 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 >
2024-04-13 00:51:30 +08:00
< p > Last article we were compiling < a href = "TODO" > < strong > Rust Apps< / strong > < / a > for < a href = "TODO" > < strong > Apache NuttX RTOS< / strong > < / a > (QEMU RISC-V 32-bit). And we hit a < strong > baffling error< / strong > …< / p >
< 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 >
< p > Rust compiles for < strong > Soft-Float< / strong > , but NuttX expects < strong > Double-Float< / strong > < / p >
< 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 >
< p > TODO: Pic of double float vs soft float < / p >
< 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 >
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< p > TODO< / p >
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< p > TODO: Compile nuttx, Hello.c< / p >
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< p > But the rest of NuttX is Double-Precision Hardware Floating-Point!< / p >
< p > (< code > -march=rv32imafdc -mabi=ilp32d< / code > )< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > $ make --trace
...
riscv64-unknown-elf-gcc \
-c \
-fno-common \
-Wall \
-Wstrict-prototypes \
-Wshadow \
-Wundef \
-Wno-attributes \
-Wno-unknown-pragmas \
-Wno-psabi \
-Os \
-fno-strict-aliasing \
-fomit-frame-pointer \
-ffunction-sections \
-fdata-sections \
-g \
-march=rv32imafdc \
-mabi=ilp32d \
-isystem nuttx/include \
-D__NuttX__ \
-DNDEBUG \
-pipe \
-I " apps/include" \
-Dmain=hello_main \
hello_main.c \
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-o hello_main.c...apps.examples.hello.o
< / code > < / pre > < / div >
< p > TODO: Target, Rustc< / p >
< p > That’ < a href = "https://lupyuen.github.io/articles/rust3#how-nuttx-compiles-rust-apps" > NuttX builds Rust Apps< / a > for < code > riscv32i-unknown-none-elf< / code > (Software Floating-Point)…< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Compile `hello_rust_main.rs` to `hello_rust.o`
## for Rust Target: RISC-V 32-bit (Soft-Float)
rustc \
--edition 2021 \
--emit obj \
-g \
--target riscv32i-unknown-none-elf \
-C panic=abort \
-O \
hello_rust_main.rs \
-o hello_rust_main.rs...apps.examples.hello_rust.o
< / code > < / pre > < / div >
< p > Watch closely as we compare < strong > GCC Compiler< / strong > with < strong > Rust Compiler< / strong > …< / p >
2024-04-15 11:32:01 +08:00
< span style = "font-size:90%" >
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< div > < table > < thead > < tr > < th > GCC Compiler< / th > < th > Rust Compiler< / th > < / tr > < / thead > < tbody >
2024-04-15 10:58:04 +08:00
< tr > < td > < em > riscv64-unknown-elf-gcc< / em > < br > < em > hello_main.c< / em > < / td > < td > < em > rustc< / em > < br > < em > hello_rust_main.rs< / em > < / td > < / tr >
< tr > < td > < em > -march< / em > < br > < strong > rv32imafdc< / strong > < / td > < td > < em > – < / em > < br > < strong > riscv32i-unknown-none-elf< / strong > < / td > < / tr >
< tr > < td > < em > -mabi< / em > < br > < strong > ilp32d< / strong > < / td > < td > < / td > < / tr >
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< / tbody > < / table >
2024-04-15 11:32:01 +08:00
< / div > < / span >
< p > < em > Hmmm something different about the Floats…< / em > < / p >
< p > Yep GCC supports (Double-Precision) < strong > Hardware Floating-Point< / strong > …< / p >
< p > Rust Compiler only supports < strong > Software Floating-Point< / strong > !< / p >
< span style = "font-size:90%" >
< div > < table > < thead > < tr > < th > GCC Compiler< / th > < th > Rust Compiler< / th > < / tr > < / thead > < tbody >
< tr > < td > < strong > rv32imafdc< / strong > < / td > < td > < strong > riscv32i< / strong > < / td > < / tr >
< tr > < td > - < strong > I< / strong > : Integer< / td > < td > - < strong > I< / strong > : Integer< / td > < / tr >
< tr > < td > - < strong > F< / strong > : Single Hard-Float< / td > < td > < em > (Soft-Float)< / em > < / td > < / tr >
< tr > < td > - < strong > D< / strong > : Double Hard-Float< / td > < td > < em > (Soft-Float)< / em > < / td > < / tr >
< / tbody > < / table >
< / div > < / span >
2024-04-15 11:53:07 +08:00
< p > And that’ ’ < / p >
2024-04-15 11:32:01 +08:00
< p > To verify, we dump the < strong > ELF Headers< / strong > for GCC and Rust Compiler Outputs…< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## ELF Header for GCC Output:
## Double-Precision Hardware Floating-Point
2024-04-15 10:45:47 +08:00
$ riscv64-unknown-elf-readelf \
--file-header --arch-specific \
../apps/examples/hello/*hello.o
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2' s complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: REL (Relocatable file)
Machine: RISC-V
Version: 0x1
Entry point address: 0x0
Start of program headers: 0 (bytes into file)
Start of section headers: 3776 (bytes into file)
Flags: 0x5, RVC, double-float ABI
Size of this header: 52 (bytes)
Size of program headers: 0 (bytes)
Number of program headers: 0
Size of section headers: 40 (bytes)
Number of section headers: 26
Section header string table index: 25
Attribute Section: riscv
File Attributes
Tag_RISCV_stack_align: 16-bytes
Tag_RISCV_arch: " rv32i2p0_m2p0_a2p0_f2p0_d2p0_c2p0"
2024-04-15 11:32:01 +08:00
## ELF Header for Rust Compiler Output
## Software Floating-Point
2024-04-15 10:45:47 +08:00
$ riscv64-unknown-elf-readelf \
--file-header --arch-specific \
../apps/examples/hello_rust/*hello_rust.o
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2' s complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: REL (Relocatable file)
Machine: RISC-V
Version: 0x1
Entry point address: 0x0
Start of program headers: 0 (bytes into file)
Start of section headers: 10240 (bytes into file)
Flags: 0x0
Size of this header: 52 (bytes)
Size of program headers: 0 (bytes)
Number of program headers: 0
Size of section headers: 40 (bytes)
Number of section headers: 29
Section header string table index: 1
Attribute Section: riscv
File Attributes
Tag_RISCV_stack_align: 16-bytes
Tag_RISCV_arch: " rv32i2p1"
< / code > < / pre > < / div >
< p > Change rust to double float < / p >
< p > We have a problem compiling < a href = "https://lupyuen.github.io/articles/rust3#software-vs-hardware-floating-point" > Rust Apps for QEMU RISC-V 32-bit< / a > …< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > $ make
LD: nuttx
riscv64-unknown-elf-ld: nuttx/nuttx/staging/libapps.a
(hello_rust_main.rs...nuttx.apps.examples.hello_rust_1.o):
can' t link soft-float modules with double-float modules
riscv64-unknown-elf-ld: failed to merge target specific data of file
nuttx/staging/libapps.a
(hello_rust_main.rs...nuttx.apps.examples.hello_rust_1.o)
2024-04-15 08:44:59 +08:00
< / code > < / pre > < / div >
< p > TODO: Pic of Rust Won’ < / p >
< h1 id = "rust-wont-double-float" > < a class = "doc-anchor" href = "#rust-wont-double-float" > §< / a > 2 Rust Won’ < / h1 >
2024-04-15 07:36:02 +08:00
< p > TODO< / p >
< p > Change Rust target< / p >
< p > Nope doesn’ < / p >
< p > Here are the targets< / p >
< p > Need custom target< / p >
< p > Gcc targets< / p >
2024-04-12 19:40:46 +08:00
< p > < em > Does Rust support Double-Precision Hardware Floating-Point?< / em > < / p >
< p > We’ < code > riscv32gc-unknown-none-elf< / code > …< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > $ rustup target list | grep riscv
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 >
< p > But nope it’ < code > riscv32gc-unknown-none-elf< / code > …< / p >
< ul >
< li > < a href = "https://docs.rust-embedded.org/embedonomicon/custom-target.html" > Custom Target for Rust< / a > < / li >
< / ul >
2024-04-15 07:36:02 +08:00
< p > < em > How to see the Targets supported by GCC?< / em > < / p >
< p > Like this…< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > $ 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 > < a href = "https://gcc.gnu.org/onlinedocs/gcc/RISC-V-Options.html#index-mabi-5" > (As explained here)< / a > < / p >
2024-04-15 11:53:07 +08:00
< p > TODO: Pic of 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 >
< p > TODO< / p >
2024-04-12 19:40:46 +08:00
< p > Let’ < code > riscv32i< / code > and < code > riscv64gc< / code > to compare…< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > $ rustc \
+nightly \
-Z unstable-options \
--print target-spec-json \
--target riscv32i-unknown-none-elf
{
" arch" : " riscv32" ,
" atomic-cas" : false,
" cpu" : " generic-rv32" ,
" data-layout" : " e-m:e-p:32:32-i64:64-n32-S128" ,
" eh-frame-header" : false,
" emit-debug-gdb-scripts" : false,
" is-builtin" : true,
" linker" : " rust-lld" ,
" linker-flavor" : " ld.lld" ,
" llvm-target" : " riscv32" ,
" max-atomic-width" : 0,
" panic-strategy" : " abort" ,
" relocation-model" : " static" ,
" target-pointer-width" : " 32"
}
$ rustc \
+nightly \
-Z unstable-options \
--print target-spec-json \
--target riscv64gc-unknown-none-elf
{
" arch" : " riscv64" ,
" code-model" : " medium" ,
" cpu" : " generic-rv64" ,
" data-layout" : " e-m:e-p:64:64-i64:64-i128:128-n32:64-S128" ,
" eh-frame-header" : false,
" emit-debug-gdb-scripts" : false,
" features" : " +m,+a,+f,+d,+c" ,
" is-builtin" : true,
" linker" : " rust-lld" ,
" linker-flavor" : " ld.lld" ,
" llvm-abiname" : " lp64d" ,
" llvm-target" : " riscv64" ,
" max-atomic-width" : 64,
" panic-strategy" : " abort" ,
" relocation-model" : " static" ,
" supported-sanitizers" : [
" kernel-address"
],
" target-pointer-width" : " 64"
}
< / code > < / pre > < / div >
< p > Based on the above, we create our Rust Custom Target: < a href = "riscv32gc-unknown-none-elf.json" > riscv32gc-unknown-none-elf.json< / a > < / p >
< div class = "example-wrap" > < pre class = "language-json" > < code > {
" arch" : " riscv32" ,
" cpu" : " generic-rv32" ,
" data-layout" : " e-m:e-p:32:32-i64:64-n32-S128" ,
" eh-frame-header" : false,
" emit-debug-gdb-scripts" : false,
" features" : " +m,+a,+f,+d,+c" ,
" linker" : " rust-lld" ,
" linker-flavor" : " ld.lld" ,
" llvm-abiname" : " ilp32d" ,
" llvm-target" : " riscv32" ,
" max-atomic-width" : 0,
" panic-strategy" : " abort" ,
" relocation-model" : " static" ,
" target-pointer-width" : " 32"
}
< / code > < / pre > < / div >
< p > Which is based on < code > riscv32i< / code > with these changes…< / p >
< ul >
< li >
< p > Removed < code > " atomic-cas" : false< / code > < / p >
< / li >
< li >
< p > Added < code > " features" : " +m,+a,+f,+d,+c" < / code > < / p >
< / li >
< li >
< p > Removed < code > " is-builtin" : true< / code > < / p >
< / li >
< li >
< p > Added < code > " llvm-abiname" : " ilp32d" < / code > < / p >
< p > (< code > ilp32d< / code > comes from < code > make --trace< / code > above)< / p >
< p > < a href = "https://lupyuen.github.io/articles/rust#custom-rust-target-for-bl602" > (More about < code > llvm-abiname< / code > )< / a > < / p >
< / li >
< / ul >
2024-04-15 11:53:07 +08:00
< p > TODO: Pic of Rust Core Library< / p >
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 >
< p > TODO< / p >
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< p > Now we build the Rust Core Library for < code > riscv32gc< / code > …< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Verify our Custom Target
rustc \
--print cfg \
--target riscv32gc-unknown-none-elf.json
## Build the Rust Core Library for `riscv32gc`
## Ignore the error: `app already exists`
cargo new app
pushd app
cargo clean
## Ignore the error: `can' t find crate for std`
cargo build \
-Zbuild-std=core,alloc \
--target ../riscv32gc-unknown-none-elf.json
popd
< / code > < / pre > < / div >
< p > We rebuild our Rust App with the new Rust Custom Target (linked to our Rust Core Library)…< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Compile our Rust App.
## Changed the target to riscv32gc-unknown-none-elf.json
rustc \
--edition 2021 \
--emit obj \
-g \
--target riscv32gc-unknown-none-elf.json \
-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
## Dump the ELF Header. Should show:
## Flags: 0x5, RVC, double-float ABI
riscv64-unknown-elf-readelf \
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--file-header --arch-specific \
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../apps/examples/hello_rust/*hello_rust.o
## NuttX should link and execute correctly now
cp \
../apps/examples/hello_rust/*hello_rust.o \
../apps/examples/hello_rust/*hello_rust_1.o
pushd ../nuttx
make
qemu-system-riscv32 \
-semihosting \
-M virt,aclint=on \
-cpu rv32 \
-smp 8 \
-bios none \
-kernel nuttx \
-nographic
popd
< / code > < / pre > < / div >
< p > And it works!< / p >
2024-04-15 07:36:02 +08:00
< 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 >
< p > TODO< / p >
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< p > < em > Our Rust App links OK! Has the ELF Header changed?< / em > < / p >
< p > Yep the ELF Header has changed from Soft-Float to Double-Float…< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > ## Before Custom Target
$ riscv64-unknown-elf-readelf \
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--file-header --arch-specific \
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../apps/examples/hello_rust/*hello_rust_1.o
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2' s complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: REL (Relocatable file)
Machine: RISC-V
Version: 0x1
Entry point address: 0x0
Start of program headers: 0 (bytes into file)
Start of section headers: 10240 (bytes into file)
Flags: 0x0
Size of this header: 52 (bytes)
Size of program headers: 0 (bytes)
Number of program headers: 0
Size of section headers: 40 (bytes)
Number of section headers: 29
Section header string table index: 1
Attribute Section: riscv
File Attributes
Tag_RISCV_stack_align: 16-bytes
Tag_RISCV_arch: " rv32i2p1"
## After Custom Target
$ riscv64-unknown-elf-readelf \
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--file-header --arch-specific \
2024-04-12 19:40:46 +08:00
../apps/examples/hello_rust/*hello_rust.o
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2' s complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: REL (Relocatable file)
Machine: RISC-V
Version: 0x1
Entry point address: 0x0
Start of program headers: 0 (bytes into file)
Start of section headers: 10352 (bytes into file)
Flags: 0x5, RVC, double-float ABI
Size of this header: 52 (bytes)
Size of program headers: 0 (bytes)
Number of program headers: 0
Size of section headers: 40 (bytes)
Number of section headers: 29
Section header string table index: 1
Attribute Section: riscv
File Attributes
Tag_RISCV_stack_align: 16-bytes
Tag_RISCV_arch: " rv32i2p1_m2p0_a2p1_f2p2_d2p2_c2p0_zicsr2p0"
## Which looks similar to other C Binaries
$ 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/*hello.o
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2' s complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: REL (Relocatable file)
Machine: RISC-V
Version: 0x1
Entry point address: 0x0
Start of program headers: 0 (bytes into file)
Start of section headers: 3776 (bytes into file)
Flags: 0x5, RVC, double-float ABI
Size of this header: 52 (bytes)
Size of program headers: 0 (bytes)
Number of program headers: 0
Size of section headers: 40 (bytes)
Number of section headers: 26
Section header string table index: 25
Attribute Section: riscv
File Attributes
Tag_RISCV_stack_align: 16-bytes
Tag_RISCV_arch: " rv32i2p0_m2p0_a2p0_f2p0_d2p0_c2p0"
< / code > < / pre > < / div >
2024-04-15 07:36:02 +08:00
< p > How would Linux Kernel handle these uncommon targets?< / p >
< p > This Rust Compiler Issue might be relevant…< / p >
< ul >
< li > < a href = "https://github.com/rust-lang/rust/issues/65024" > Allow building for hard-float targets in RISC-V< / a > < / li >
< / ul >
< 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 >
< p > TODO< / p >
< p > < strong > Exercise for the Reader:< / strong > Last article we TODO< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > $ tools/configure.sh rv-virt:nsh64
$ 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
make[2]: *** [nuttx/apps/Application.mk:275: hello_rust.o] Error 1
make[1]: *** [Makefile:51: nuttx/apps/examples/hello_rust_all] Error 2
make: *** [tools/LibTargets.mk:232: nuttx/apps/libapps.a] Error 2
< / code > < / pre > < / div >
< p > Which says that < em > riscv64i-unknown-none-elf< / em > isn’ < / p >
< p > (Should be < em > riscv64gc-unknown-none-elf< / em > instead)< / p >
< p > Fix the build?
Custom Target?
(10 points)< / p >
< h1 id = "whats-next" > < a class = "doc-anchor" href = "#whats-next" > §< / a > 7 What’ < / h1 >
< p > TODO< / p >
< 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 >
< 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 >
< h1 id = "appendix-rust-compiler-options" > < a class = "doc-anchor" href = "#appendix-rust-compiler-options" > §< / a > 8 Appendix: Rust Compiler Options< / h1 >
< p > TODO< / p >
2024-04-12 19:40:46 +08:00
< p > < em > How did we figure out the rustc options?< / em > < / p >
< p > < code > cargo build< / code > will call < code > rustc< / code > with a whole bunch of options.< / p >
< p > We ran < code > cargo build -v< / code > to dump the < code > rustc< / code > options that were used to compile a Rust App with our Custom Rust Core Library for < code > riscv32gc< / code > …< / p >
< div class = "example-wrap" > < pre class = "language-bash" > < code > $ cargo build -v \
-Zbuild-std=core,alloc \
--target ../riscv32gc-unknown-none-elf.json
Compiling compiler_builtins v0.1.101
Compiling core v0.0.0 ($HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core)
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc --crate-name build_script_build --edition=2018 $HOME/.cargo/registry/src/index.crates.io-6f17d22bba15001f/compiler_builtins-0.1.101/build.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 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`
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc --crate-name core --edition=2021 $HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/lib.rs --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=$HOME/riscv/nuttx-rust-app/app/target/debug/deps --cap-lints allow`
Running `$HOME/riscv/nuttx-rust-app/app/target/debug/build/compiler_builtins-9bd0bac7535b33a8/build-script-build`
Compiling rustc-std-workspace-core v1.99.0 ($HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/rustc-std-workspace-core)
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc --crate-name rustc_std_workspace_core --edition=2021 $HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/rustc-std-workspace-core/lib.rs --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`
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc --crate-name compiler_builtins --edition=2018 $HOME/.cargo/registry/src/index.crates.io-6f17d22bba15001f/compiler_builtins-0.1.101/src/lib.rs --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" ' `
Compiling alloc v0.0.0 ($HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc)
Running `$HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/bin/rustc --crate-name alloc --edition=2021 $HOME/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/lib.rs --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=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/libcore-d271c6ebb87f9b41.rmeta --cap-lints allow`
Compiling app v0.1.0 ($HOME/riscv/nuttx-rust-app/app)
Running `$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=$HOME/riscv/nuttx-rust-app/app/target/riscv32gc-unknown-none-elf/debug/deps/libcore-d271c6ebb87f9b41.rlib' -Z unstable-options`
error[E0463]: can' t find crate for `std`
|
= note: the `riscv32gc-unknown-none-elf` target may not support the standard library
= note: `std` is required by `app` because it does not declare `#![no_std]`
= help: consider building the standard library from source with `cargo build -Zbuild-std`
error: cannot find macro `println` in this scope
--> src/main.rs:2:5
|
2 | println!(" Hello, world!" );
| ^^^^^^^
error: `#[panic_handler]` function required, but not found
For more information about this error, try `rustc --explain E0463`.
error: could not compile `app` (bin " app" ) due to 3 previous errors
Caused by:
process didn' t exit successfully: `$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
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