123 lines
2.1 KiB
C
123 lines
2.1 KiB
C
|
asm(".code16gcc");
|
||
|
|
#include <stddef.h>
|
||
|
|
#include "bios.h"
|
||
|
|
#include "segment.h"
|
||
|
|
#include "ioport.h"
|
||
|
|
#include "processor-flags.h"
|
||
|
|
#include "e820.h"
|
||
|
|
|
||
|
|
static inline void set_fs(uint16_t seg)
|
||
|
|
{
|
||
|
|
asm volatile("movw %0,%%fs" : : "rm" (seg));
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline uint8_t rdfs8(unsigned long addr)
|
||
|
|
{
|
||
|
|
uint8_t v;
|
||
|
|
|
||
|
|
asm volatile("addr32 movb %%fs:%1,%0" : "=q" (v) : "m" (*(uint8_t *)addr));
|
||
|
|
|
||
|
|
return v;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline uint32_t rdfs32(unsigned long addr)
|
||
|
|
{
|
||
|
|
uint32_t v;
|
||
|
|
|
||
|
|
asm volatile("addr32 movl %%fs:%1,%0" : "=r" (v) : "m" (*(uint32_t *)addr));
|
||
|
|
|
||
|
|
return v;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline uint16_t rdcs16(void *p)
|
||
|
|
{
|
||
|
|
uint32_t addr = ((uintptr_t) p) & 65535;
|
||
|
|
uint16_t v;
|
||
|
|
|
||
|
|
asm volatile("addr32 movw %%cs:%1,%0" : "=r" (v) : "m" (*(uint32_t *)addr));
|
||
|
|
|
||
|
|
return v;
|
||
|
|
}
|
||
|
|
|
||
|
|
uint16_t e820_seg;
|
||
|
|
|
||
|
|
bioscall void e820_query_map(struct biosregs *regs)
|
||
|
|
{
|
||
|
|
uint32_t map_size;
|
||
|
|
uint32_t ndx;
|
||
|
|
|
||
|
|
set_fs(rdcs16(&e820_seg));
|
||
|
|
|
||
|
|
ndx = regs->ebx;
|
||
|
|
|
||
|
|
map_size = rdfs32(offsetof(struct e820map, nr_map));
|
||
|
|
|
||
|
|
if (ndx < map_size) {
|
||
|
|
uint32_t start;
|
||
|
|
unsigned int i;
|
||
|
|
uint8_t *p;
|
||
|
|
|
||
|
|
start = offsetof(struct e820map, map[ndx]);
|
||
|
|
|
||
|
|
p = (void *) regs->edi;
|
||
|
|
|
||
|
|
for (i = 0; i < sizeof(struct e820entry); i++)
|
||
|
|
*p++ = rdfs8(start + i);
|
||
|
|
}
|
||
|
|
|
||
|
|
regs->eax = SMAP;
|
||
|
|
regs->ecx = sizeof(struct e820entry);
|
||
|
|
regs->ebx = ++ndx;
|
||
|
|
|
||
|
|
if (ndx >= map_size)
|
||
|
|
regs->ebx = 0; /* end of map */
|
||
|
|
}
|
||
|
|
|
||
|
|
bioscall void int15_handler(struct biosregs *regs)
|
||
|
|
{
|
||
|
|
switch (regs->eax) {
|
||
|
|
case 0xe820:
|
||
|
|
e820_query_map(regs);
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
/* Set CF to indicate failure. */
|
||
|
|
regs->eflags |= X86_EFLAGS_CF;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* It's probably much more useful to make this print to the serial
|
||
|
|
* line rather than print to a non-displayed VGA memory
|
||
|
|
*/
|
||
|
|
static inline void int10_putchar(struct biosregs *args)
|
||
|
|
{
|
||
|
|
uint8_t al = args->eax & 0xFF;
|
||
|
|
|
||
|
|
outb(0x3f8, al);
|
||
|
|
}
|
||
|
|
|
||
|
|
#define VBE_STATUS_OK 0x004F
|
||
|
|
#define VBE_STATUS_FAIL 0x014F
|
||
|
|
|
||
|
|
static void int10_vesa(struct biosregs *args)
|
||
|
|
{
|
||
|
|
args->eax = VBE_STATUS_FAIL;
|
||
|
|
}
|
||
|
|
|
||
|
|
bioscall void int10_handler(struct biosregs *args)
|
||
|
|
{
|
||
|
|
uint8_t ah;
|
||
|
|
|
||
|
|
ah = (args->eax & 0xff00) >> 8;
|
||
|
|
|
||
|
|
switch (ah) {
|
||
|
|
case 0x0e:
|
||
|
|
int10_putchar(args);
|
||
|
|
break;
|
||
|
|
case 0x4f:
|
||
|
|
int10_vesa(args);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
}
|