alcedo/kernel/kernel.nim

{.link: "../boot.o".}
{.passL: "-ffreestanding -target i386 -nostdlib -T arch/i386/linker.ld".}
{.passC: "-ffreestanding -nostdlib --target=i386-pc-none-elf -march=i386".}

import tty, gdt, interrupts, serial

const version {.strdefine.} = "UNKNOWN"

type
  MemoryPointer{.unchecked.} = ptr array[0, char]

proc memcpy*(dest: ByteAddress, src: ByteAddress, count: int){.exportc.} =
  var destMem = cast[MemoryPointer](dest)
  var srcMem = cast[MemoryPointer](src)
  for i in 0..count-1:
    destMem[i] = srcMem[i]

proc memset*(dest: ByteAddress, value: char, count: int){.exportc.} =
  var destMem = cast[MemoryPointer](dest)
  for i in 0..count-1:
    destMem[i] = value

proc kernelMain() {.exportc: "kernel_main"}=
  serial.init()
  serial.writeLine("Version:" & (version))
  serial.writeLine("Booting OS")
  gdt.gdtInstall()
  serial.writeLine("GDT installed")
  interrupts.idtInstall()
  serial.writeLine("IDT installed")
  tty.init()
  tty.writeLine("Version:" & version)
  tty.writeLine("Hello World!")
  tty.write("MAX_INT:")
  tty.writeLine(high(int))
  tty.write("LMIN_INT:")
  tty.writeLine((low(int)+1))
  tty.write("MAX_UINT:")
  tty.writeLine(high(uint32))
  asm """int $0x3"""