54 lines
1.5 KiB
C
54 lines
1.5 KiB
C
/*
|
|
* Copyright (c) 2023 Intel Corporation
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
#include <zephyr/kernel.h>
|
|
|
|
#define DATA_SIZE_K(n) (n * 1024u)
|
|
#define RSDP_SIGNATURE ((uint64_t)0x2052545020445352)
|
|
#define EBDA_ADD (0x040e)
|
|
#define BIOS_RODATA_ADD (0xe0000)
|
|
#define BIOS_EXT_DATA_LOW (0x80000UL)
|
|
#define BIOS_EXT_DATA_HIGH (0x100000UL)
|
|
|
|
static uintptr_t bios_search_rsdp_buff(uintptr_t search_phy_add, uint32_t search_length)
|
|
{
|
|
uint64_t *search_buff;
|
|
|
|
k_mem_map_phys_bare((uint8_t **)&search_buff, search_phy_add, search_length, 0);
|
|
if (!search_buff) {
|
|
return 0;
|
|
}
|
|
|
|
for (int i = 0; i < search_length / 8u; i++) {
|
|
if (search_buff[i] == RSDP_SIGNATURE) {
|
|
k_mem_unmap_phys_bare((uint8_t *)search_buff, search_length);
|
|
return (search_phy_add + (i * 8u));
|
|
}
|
|
}
|
|
k_mem_unmap_phys_bare((uint8_t *)search_buff, search_length);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void *bios_acpi_rsdp_get(void)
|
|
{
|
|
uint8_t *bios_ext_data, *zero_page_base;
|
|
uintptr_t search_phy_add, rsdp_phy_add;
|
|
|
|
k_mem_map_phys_bare(&zero_page_base, 0, DATA_SIZE_K(4u), 0);
|
|
bios_ext_data = EBDA_ADD + zero_page_base;
|
|
search_phy_add = (uintptr_t)((*(uint16_t *)bios_ext_data) << 4u);
|
|
k_mem_unmap_phys_bare(zero_page_base, DATA_SIZE_K(4u));
|
|
|
|
if ((search_phy_add >= BIOS_EXT_DATA_LOW) && (search_phy_add < BIOS_EXT_DATA_HIGH)) {
|
|
rsdp_phy_add = bios_search_rsdp_buff(search_phy_add, DATA_SIZE_K(1u));
|
|
if (rsdp_phy_add) {
|
|
return (void *)rsdp_phy_add;
|
|
}
|
|
}
|
|
return (void *)bios_search_rsdp_buff(BIOS_RODATA_ADD, DATA_SIZE_K(128u));
|
|
}
|