struct acpi_rsdp *apci_get_RSDP()
{
/* The root structure may in the first KB of EBDA or from 0xE0000 to 0xFFFFF */
addr_t ebda_bottom = *(uint16_t *)(0x40e) << 4;
addr_t tmp = ebda_bottom;
addr_t end = 0xFFFFF;
struct acpi_rsdp *rsdp;
if(0xA0000 < ebda_bottom || ((0xA0000 - ebda_bottom) > (128 * 1024))) {
printk(0, "[acpi]: got invalid lower ebda address (%x)\n", ebda_bottom);
return 0;
}
/* scan the EBDA and other region */
while(tmp < end)
{
rsdp = (struct acpi_rsdp *)tmp;
if(!memcmp(rsdp->sig, "RSD PTR ", 8) && rsdp_validate_checksum(rsdp))
return rsdp;
tmp += 16;
if(tmp >= 0xA0000 && tmp <0xE0000) tmp = 0xE0000;
}
return 0;
}
static struct acpi_rsdp *apci_get_RSDP (void)
{
// The root structure may in the first KB of EBDA or from 0xE0000 to 0xFFFFF.
addr_t ebda_bottom = *(uint16_t *)(0x40e + PHYS_PAGE_MAP) << 4;
addr_t tmp = ebda_bottom;
addr_t end = 0xFFFFF;
struct acpi_rsdp *rsdp;
if((0xA0000) < ebda_bottom || ((0xA0000 - ebda_bottom) > (128 * 1024))) {
printk(0, "[ACPI]: got invalid lower ebda address (%x)\n", ebda_bottom);
tmp = 0xE0000;
//return 0;
}
// Scan the EBDA and other region.
while(tmp < end)
{
rsdp = (struct acpi_rsdp *)(tmp + PHYS_PAGE_MAP);
if(!memcmp(rsdp->sig, "RSD PTR ", 8) && rsdp_validate_checksum(rsdp))
return rsdp;
tmp += 16;
if(tmp >= 0xA0000 && tmp <0xE0000)
tmp = 0xE0000;
}
return 0;
}