Files
5150/fat12boot.c

54 lines
1.2 KiB
C

#include <stdint.h>
#include <stdlib.h>
#include "fat12.h"
#define kPolmonAddress ((void*)0x0600)
#define kFatAddress ((void*)0x1000)
#define kRootDirAddress ((void*)0x1200)
static int putchar(int c) {
register uint8_t khar asm("al") = c;
register uint8_t func asm("ah") = 0x0e;
register uint8_t page asm("bh") = 0;
asm volatile("int $0x10" ::"r"(khar), "r"(func), "r"(page) : "bp");
return c;
}
static int puts(const char* msg) {
while (*msg) {
putchar(*msg++);
}
return 0;
}
__attribute__((noreturn)) static void die(const char* msg) {
puts(msg);
while (1) {
}
__builtin_unreachable();
}
__attribute__((noreturn)) static void jump(void* addr) {
asm volatile("ljmp $0,%0" ::"i"(addr));
__builtin_unreachable();
}
__attribute__((noreturn)) static void loadpolmon() {
if (fat12_init(kFatAddress, kRootDirAddress)) {
die("fi");
}
while (fat12_readfile("POLIO COM", kPolmonAddress)) {
asm volatile("mov $00, %%ah \n\t"
"int $0x16 \n\t" ::
: "ax");
}
jump(kPolmonAddress);
}
int main() { loadpolmon(); }