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.global start
.extern kernel_main

.set noreorder

.set STACKSIZE, 0x1000

.section .text

start:
	la $sp, stack
	addiu $sp, STACKSIZE - 32
	jal kernel_main
	nop
	b .
	nop

.section .bss
stack:
	.space STACKSIZE

Code: Select all

#include <stdint.h>
#include <stddef.h>

void kernel_main()
{
	uint16_t* buffer = (uint16_t*) 0xB8000;
	for (size_t i = 0; i < 80*25; i++)
		buffer[i] = ((uint16_t) '&') | ((uint8_t) 7) << 8;
}

Code: Select all

OUTPUT_FORMAT(elf32-littlemips)
OUTPUT_ARCH(mips:isa32)
ENTRY(start)

SECTIONS
{
	.text (0xBFC0) :
	{
		*(.text)
		*(.text.*)
		*(.stub)
		*(.gnu.linkonce.t.*)
	}

	.rodata ALIGN(4K) :
	{
		*(.rodata*)
		*(.gnu.linkonce.r.*)
	}

	.data ALIGN(4K) :
	{
		*(.data*)
		*(.gnu.linkonce.d.*)
	}

	.bss ALIGN(4K) :
	{
		*(.common)
		*(.bss*)
		*(.gnu.linkonce.b.*)
	}

	/DISCARD/ :
	{
		*(.gcc_except_table)
		*(.eh_frame)
		*(.note)
		*(.comment)
		*(.rel.*)
		*(.rela.*)
	}
}

Code: Select all

#!/bin/bash
set -e
export PREFIX="/usr/local/cross"
export TARGET=mipsel-elf
export PATH="$PREFIX/bin:$PATH"
mipsel-elf-as -o entry.o entry.s -mfix-loongson2f-nop -mfix-loongson2f-jump
#mipsel-elf-gcc -o main.o -c main.c -std=c99 -Wall -Wextra -Werror -ffreestanding -nostdlib -fno-builtin -nostartfiles -nodefaultlibs -O2 -Wa,-mfix-loongson2f-nop,-mfix-loongson2f-jump
mipsel-elf-gcc -o main.o -c main-minimal.c -std=c99 -Wall -Wextra -Werror -ffreestanding -nostdlib -fno-builtin -nostartfiles -nodefaultlibs -O2 -Wa,-mfix-loongson2f-nop,-mfix-loongson2f-jump
mipsel-elf-ld -T ldscript -o kernel.elf entry.o main.o
#sudo mount /dev/sda1 /mnt/boot
#sudo cp kernel.elf /mnt/boot
#sudo umount /dev/sda1