diff options
| -rw-r--r-- | src/mainboard/google/brya/bootblock.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/mainboard/google/brya/bootblock.c b/src/mainboard/google/brya/bootblock.c index 1651337c49..bd7100a8dc 100644 --- a/src/mainboard/google/brya/bootblock.c +++ b/src/mainboard/google/brya/bootblock.c @@ -1,5 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0-or-later */ +#include <arch/mmio.h> #include <baseboard/variants.h> #include <bootblock_common.h> #include <console/console.h> @@ -13,6 +14,32 @@ #define SI_DESC_REGION_SZ 4096 #define PMC_DESC_7_BYTE3 0xc32 +/* Flash Master 1 : HOST/BIOS */ +#define FLMSTR1 0x80 + +/* Flash signature Offset */ +#define FLASH_SIGN_OFFSET 0x10 +#define FLMSTR_WR_SHIFT_V2 20 +#define FLASH_VAL_SIGN 0xFF0A55A + +/* It checks whether host(Flash Master 1) has write access to the Descriptor Region or not */ +static int is_descriptor_writeable(uint8_t *desc) +{ + /* Check flash has valid signature */ + if (read32((void *)(desc + FLASH_SIGN_OFFSET)) != FLASH_VAL_SIGN) { + printk(BIOS_DEBUG, "Flash Descriptor is not valid\n"); + return 0; + } + + /* Check host has write access to the Descriptor Region */ + if (!((read32((void *)(desc + FLMSTR1)) >> FLMSTR_WR_SHIFT_V2) & BIT(0))) { + printk(BIOS_DEBUG, "Host doesn't have write access to Descriptor Region\n"); + return 0; + } + + return 1; +} + /* It updates PMC Descriptor in the Descriptor Region */ static void configure_pmc_descriptor(void) { @@ -29,6 +56,9 @@ static void configure_pmc_descriptor(void) return; } + if (!is_descriptor_writeable(si_desc_buf)) + return; + if (si_desc_buf[PMC_DESC_7_BYTE3] != 0x40) { printk(BIOS_DEBUG, "Update of PMC Descriptor is not required!\n"); return; |