rulimine/common/sys/e820.s2.c
2022-09-02 02:29:12 +02:00

45 lines
823 B
C

#if defined (BIOS)
#include <stdint.h>
#include <stddef.h>
#include <sys/e820.h>
#include <lib/real.h>
#include <lib/misc.h>
#include <lib/print.h>
#include <mm/pmm.h>
#define MAX_E820_ENTRIES 256
struct memmap_entry e820_map[MAX_E820_ENTRIES];
size_t e820_entries = 0;
void init_e820(void) {
struct rm_regs r = {0};
for (size_t i = 0; i < MAX_E820_ENTRIES; i++) {
struct memmap_entry entry;
r.eax = 0xe820;
r.ecx = 24;
r.edx = 0x534d4150;
r.edi = (uint32_t)&entry;
rm_int(0x15, &r, &r);
if (r.eflags & EFLAGS_CF) {
e820_entries = i;
return;
}
e820_map[i] = entry;
if (!r.ebx) {
e820_entries = ++i;
return;
}
}
panic(false, "Too many E820 entries!");
}
#endif