lupyuen/pinephone-nuttx
1
0
Fork 0
mirror of https://github.com/lupyuen/pinephone-nuttx.git synced 2025-01-13 05:08:32 +08:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Adding Long Packet

Browse source
This commit is contained in:
Lee Lup Yuen 2022-10-06 11:58:31 +08:00
parent 5e33e3d476
commit e2f6aa6dd7
1 changed files with 34 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

62
display.zig
View file

@ -90,43 +90,49 @@ fn compose_long_packet(
) []u8 { ) []u8 {
_ = buf; _ = buf;
debug("compose_long_packet: channel={}, cmd={x}, len={}", .{ channel, cmd, len }); debug("compose_long_packet: channel={}, cmd={x}, len={}", .{ channel, cmd, len });
// Packet Header (4 bytes): // Data Identifier (DI) (1 byte):
// TODO: // Virtual Channel Identifier (Bits 6 to 7)
// - Data Identifier (DI) (1 byte): // Data Type (Bits 0 to 5)
// Virtual Channel Identifier (Bits 6 to 7) // (Virtual Channel should be 0, I think)
// Data Type (Bits 0 to 5) assert(cmd < (1 << 6));
// (Virtual Channel should be 0, I think) const vc: u8 = 0;
const dc = 0; const dt: u8 = cmd;
const di: u8 = (vc << 6) | dt;
// - Word Count (WC) (2 bytes)： // Word Count (WC) (2 bytes)：
// Number of bytes in the Packet Payload // Number of bytes in the Packet Payload
const wc = @intCast(u16, len); const wc: u16 = @intCast(u16, len);
const wcl = @intCast(u8, wc & 0xff); const wcl: u8 = @intCast(u8, wc & 0xff);
const wch = @intCast(u8, wc >> 8); const wch: u8 = @intCast(u8, wc >> 8);
// TODO: // TODO: Error Correction Code (ECC) (1 byte):
// - Error Correction Code (ECC) (1 byte): // Allow single-bit errors to be corrected and 2-bit errors to be detected in the Packet Header
// Allow single-bit errors to be corrected and 2-bit errors to be detected in the Packet Header // See "12.3.6.12: Error Correction Code", Page 208:
// See "12.3.6.12: Error Correction Code", Page 208: // https://github.com/sipeed/sipeed2022_autumn_competition/blob/main/assets/BL808_RM_en.pdf)
// https://github.com/sipeed/sipeed2022_autumn_competition/blob/main/assets/BL808_RM_en.pdf) const ecc: u8 = 0;
const ecc = 0;
const header = [4]u8 { dc, wcl, wch, ecc }; // TODO: Checksum (CS) (2 bytes):
// 16-bit Cyclic Redundancy Check (CRC)
// See "12.3.6.13: Packet Footer", Page 210:
// https://github.com/sipeed/sipeed2022_autumn_competition/blob/main/assets/BL808_RM_en.pdf)
const cs: u16 = 0;
const csl: u8 = @intCast(u8, cs & 0xff);
const csh: u8 = @intCast(u8, cs >> 8);
// Packet Header (4 bytes): Data Identifier, Word Count, Error Correction COde
const header = [4]u8 { di, wcl, wch, ecc };
_ = header; _ = header;
// Packet Payload: // Packet Payload:
// - Data (0 to 65,541 bytes): // Data (0 to 65,541 bytes):
// Number of data bytes should match the Word Count (WC) // Number of data bytes should match the Word Count (WC)
assert(len <= 65_541); assert(len <= 65_541);
// TODO: Packet Footer: // Packet Footer: Checksum
// - Checksum (CS) (2 bytes): const footer = [2]u8 { csl, csh };
// 16-bit Cyclic Redundancy Check (CRC)
// See "12.3.6.13: Packet Footer", Page 210:
// https://github.com/sipeed/sipeed2022_autumn_competition/blob/main/assets/BL808_RM_en.pdf)
const footer = [2]u8 { 0, 0 };
_ = footer; _ = footer;
// TODO: Concatenate the header, payload and footer // TODO: Packet = Packet Header + Payload + Packet Footer
var pkt = std.mem.zeroes([1024]u8); var pkt = std.mem.zeroes([1024]u8);
assert(pkt.len >= header.len + len + footer.len); // Increase pkt size assert(pkt.len >= header.len + len + footer.len); // Increase pkt size
std.mem.copy(u8, pkt[0..header.len], &header); std.mem.copy(u8, pkt[0..header.len], &header);