130 lines
3.1 KiB
C
130 lines
3.1 KiB
C
#include "lnxboot.h"
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extern void _start();
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[[gnu::section(".lnxhead")]]
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[[gnu::used]]
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[[gnu::aligned(1)]]
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[[gnu::unavailable("not present at runtime. use setup_info instead")]]
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struct setup_info bzhead = {
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.setup_sects = 1, // 1 512-byte sector
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.boot_flag = 0xAA55,
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.syssize = 16,
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.jump_instruction = 0xEB,
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.jump_offset = sizeof(struct setup_info) - __builtin_offsetof(struct setup_info, signature),
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.signature = 0x53726448,
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.version = 0x020F,
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.loadflags = 0x01, // LOADED_HIGH,
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.kernel_alignment = 1,
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.relocatable_kernel = 1,
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.xloadflags = 0x13, // XLF_KERNEL_64 | XLF_CAN_BE_LOADED_ABOVE_4G | XLF_5LEVEL
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.cmdline_size = 255, // max command line size
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.init_size = 0x10000 // we dont need THAT much memory
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};
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struct setup_info* setup_info;
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struct boot_params* boot_params;
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unsigned short serial_port;
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void outb(unsigned short port, unsigned char value) {
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asm volatile (
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"outb %b0, %1"
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::"a" (value)
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,"d" (port)
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);
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}
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void serial_putc(char c) {
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outb(serial_port, c);
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}
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void serial_puts(const char* s) {
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while (*s) serial_putc(*(s++));
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}
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void serial_put_formatted_u64(u64 v) {
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if (v == 0) {
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serial_putc('0');
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} else {
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u64 max = 1;
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while (v > max) max *= 10;
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while (v) {
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serial_putc('0' + (u8)(v / max));
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v %= max;
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max /= 10;
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}
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}
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}
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[[gnu::section(".text._start"), gnu::naked]]
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extern void _start() {
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asm ( // grab the setup_info and boot_params locations
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"mov %%rsi, %1\n"
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"mov %%rsi, %0\n"
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"addq $0x1f1, %0"
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: "=m" (setup_info),
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"=m" (boot_params)
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);
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asm ("jmp entry");
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}
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[[gnu::section(".text._start")]]
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void entry() {
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// get the zero page
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//boot_params = (struct boot_params*)(
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// 0x202 - 0x1f1
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// + setup_info->jump_offset
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// + (u64)setup_info);
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// orignally we would try to import the serial port from the kernel (see kexec tools)
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// as you can see, we gave up!
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// serial_port = (unsigned short)*(long*)&serial_base;
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serial_port = 0x3f8;
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// construct pointers
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u8* cmdline_ptr = (u8*)((u64)setup_info->cmd_line_ptr | ((u64)boot_params->ext_cmd_line_ptr << 32));
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// check out command line
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serial_puts(cmdline_ptr);
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serial_putc('\r');
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serial_putc('\n');
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// we dont have the privilege of getting a rodata segment. any reads off our stack cause a triple fault
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// for some fucking reason. allocate our strings and shit on the stack.
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//char s_you_fucked_up[] = "!!! YOU FUCKED UP !!!\n";
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//char s_vga_you_fucked_up[] = "YOU FUCKED UP.\n";
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//char s_description[] = "A SERIOUS ERROR HAS OCCURED AND LINDOWS HAS STOPPED TO PREVENT FURTHER DAMAGE.";
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//char s_registers[] = "REGISTERS:";
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//char s_call_trace[] = "CALL TRACE:";
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//char s_dumpcore[] = "[(D)UMP CORE]";
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//char s_poweroff[] = "[(P)OWER OFF]";
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//char s_reboot[] = "[(R)EBOOT ]";
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// You fucked up.
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//serial_puts(s_you_fucked_up);
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//serial_puts(s_description);
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//serial_putc('\n');
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// register dump
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//serial_puts(s_registers);
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//serial_putc('\n');
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//serial_putc('\n');
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// call trace
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//serial_puts(s_call_trace);
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//serial_putc('\n');
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//serial_putc('\n');
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// thing
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// serial_puts("test\n");
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// serial_puts(bzhead.cmd_line_ptr);
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// Die.
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asm ("cli");
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asm ("hlt");
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}
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