int hdd_io(int hdd_n, void *buff, u16 sectors, u64 start, int read)
{
u8 sbuf[32];
rm_ctx ctx;
u32 head, cyl;
u8 dos_n = hdd2dos(hdd_n);
hdd_inf *hdd = &iodb.p_hdd[hdd_n];
lba_p *lba = pv(0x580); /* this needed for avoid stupid actions by buggy BIOSes */
int succs = 0;
/* setup initial context */
set_ctx(0, &ctx);
if (hdd->flags & HDD_LBA)
{
/* save old buffer */
mincpy(sbuf, lba, sizeof(sbuf));
/* setup LBA block */
lba->size = sizeof(lba_p);
lba->unk = 0;
lba->dst_sel = rm_seg(buff);
lba->dst_off = rm_off(buff);
lba->numb = sectors;
lba->sector = start;
ctx.ah = read ? 0x42:0x43;
ctx.dl = dos_n;
ctx.si = 0x180;
ctx.ds = 0x40; /* if DS can be 0x40, we can avoid AWARD BIOS bug of int13/AX=4B01 */
/* set additional registers to serve buggy BIOSes. */
ctx.es = ctx.ds;
ctx.di = ctx.si;
ctx.bx = ctx.si;
ctx.cx = ctx.ds;
/* do not check AH because some buggy USB BIOSes fail to clear AH on success */
succs = bios_call(0x13, &ctx);
/* restore saved buffer */
mincpy(lba, sbuf, sizeof(sbuf));
} else
{
head = d32(start) / hdd->max_sect;
cyl = head / hdd->max_head;
ctx.ah = read ? 0x02:0x03;
ctx.al = d8(sectors);
ctx.ch = d8(cyl);
ctx.cl = d8(((cyl & 0x0300) >> 2) | (d32(start) % hdd->max_sect + 1));
ctx.dh = head % hdd->max_head;
ctx.dl = dos_n;
ctx.es = rm_seg(buff);
ctx.bx = rm_off(buff);
/* do not check AH because some buggy USB BIOSes fail to clear AH on success */
succs = bios_call(0x13, &ctx);
}
return succs;
}
static int get_memory_map_entry(uint32_t * token, struct memory_map_entry * entry)
{
struct memory_map_entry buf;
struct registers regs;
regs.eax = 0xE820;
regs.ebx = *token;
regs.ecx = sizeof(struct memory_map_entry);
regs.edx = 0x534D4150;
regs.es = segment_of(&buf);
regs.di = offset_of(&buf);
bios_call(®s, 0x15);
if ((regs.flags & 1) != 0) /* CF set - error */
return 1;
if (regs.eax != 0x534D4150)
return 2;
*token = regs.ebx;
entry->address = buf.address;
entry->size = buf.size;
entry->type = buf.type;
entry->ext = buf.ext;
return 0;
}
/**
* Get the PXE entry point address.
*
* @return Whether the entry point could be found.
*/
static bool get_entry_point(void) {
bios_regs_t regs;
pxenv_t *pxenv;
pxe_t *pxe;
/* Use the PXE installation check function. */
bios_regs_init(®s);
regs.eax = INT1A_PXE_INSTALL_CHECK;
bios_call(0x1a, ®s);
if (regs.eax != INT1A_PXE_INSTALL_CHECK_RET || regs.eflags & X86_FLAGS_CF) {
dprintf("pxe: loaded via PXE but PXE not available\n");
return false;
}
/* Get the PXENV+ structure. */
pxenv = (pxenv_t *)segoff_to_linear((regs.es << 16) | regs.bx);
if (memcmp(pxenv->signature, PXENV_SIGNATURE, sizeof(pxenv->signature)) != 0) {
boot_error("PXENV+ structure has incorrect signature");
} else if (!checksum_range(pxenv, pxenv->length)) {
boot_error("PXENV+ structure is corrupt");
}
/* Get the !PXE structure. */
pxe = (pxe_t *)segoff_to_linear(pxenv->pxe_ptr);
if (memcmp(pxe->signature, PXE_SIGNATURE, sizeof(pxe->signature)) != 0) {
boot_error("!PXE structure has incorrect signature");
} else if (!checksum_range(pxe, pxe->length)) {
boot_error("!PXE structure is corrupt");
}
pxe_entry_point = pxe->entry_point_16;
return true;
}
static void dc_password_error(prt_inf *active)
{
if (conf.error_type & ET_MESSAGE) {
puts(conf.err_msg);
}
if (conf.error_type & ET_REBOOT) {
bios_reboot();
}
if (conf.error_type & ET_BOOT_ACTIVE)
{
if (active == NULL) {
puts("active partition not found\n");
} else {
boot_from_partition(active, 0);
}
}
if (conf.error_type & ET_EXIT_TO_BIOS) {
bios_call(0x18, NULL);
}
if (conf.error_type & ET_MBR_BOOT) {
autocpy(pv(0x7C00), conf.save_mbr, SECTOR_SIZE);
bios_jump_boot(boot_dsk, 0);
}
}
uint32_t get_low_memory_limit()
{
struct registers regs;
bios_call(®s, 0x12);
return regs.ax * 1024;
}
