bootboot.zig

bootboot.zig

const ExportOptions = @import("std").builtin.ExportOptions;

const FrameBufferType = enum(u8) {
  ARGB = 0,
  RGBA = 1,
  ABGR = 2,
  BGRA = 3
};

const ProtocolLevel = enum(u2) {
  MINIAMAL = 0,
  STATIC = 1,
  DYNAMIC = 2
};

const Endianess = enum(u1) {
  BIG_ENDIAN = 1,
  LITTL_ENDIAN = 0
};

const LoaderType = enum(u5) {
  BIOS = (0<<2),
  UEFI = (1<<2),
  RASPBERRY_PI = (2<<2)
};

const ProtocolInfo = extern struct {
  protocolLevel: ProtocolLevel,
  loaderType: LoaderType,
  endianness: Endianess,
};

const PlatformX8664 = extern struct {
  acpi: u64,
  smbi: u64,
  efi: u64,
  mp: u64,
  unused: [4]u64
};

const PlatformAarch64 = extern struct {
  acpi: u64,
  mmio: u64,
  efi: u64,
  unused: [5]u64
};

const ArchSpecific = extern union {
  x8664: PlatformX8664,
  aarch64: PlatformAarch64
};

const Mmap = extern struct {
  ptr: u64,
  size: u64
};

const Bootboot =  extern struct {
  magic: [4]u8,
  size: u32,
  protocol: u8,
  fbType: u8,
  numcores: u16,
  bspId: u16,
  timezone: i16,
  datetime: [8]u8,
  initrdAddress: u64,
  initrdSize: u64,
  frameBufferAddress: *u8,
  frameBufferSize: u32,
  frameBufferWidth: u32,
  frameBufferHeight: u32,
  frameBufferScanLine: u32,

  specific: ArchSpecific,
  mmap: Mmap
};

pub var boot : *Bootboot;

comptime {
  @export(boot, .{ .name = "boot", .section = "boot", .linkage = .Strong });
}

link.ld

mmio  = 0xfffffffff8000000;                    /* these are configurable for level 2 loaders */
fb    = 0xfffffffffc000000;
PHDRS
{
  boot PT_LOAD;                                /* one single loadable segment */
}
SECTIONS
{
    . = 0xffffffffffe00000;
    bootboot    = .; . += 4096;
    environment = .; . += 4096;
    .text : {
        KEEP(*(.text.boot)) *(.text .text.*)   /* code */
        *(.rodata .rodata.*)                   /* data */
        *(.data .data.*)
    } :boot
    .bss (NOLOAD) : {                          /* bss */
        . = ALIGN(16);
        *(.bss .bss.*)
        *(COMMON)
    } :boot

    /DISCARD/ : { *(.eh_frame) *(.comment) }
}