| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <console/console.h> |
| #include <ip_checksum.h> |
| #include <pc80/mc146818rtc.h> |
| #include <stdint.h> |
| #include <elog.h> |
| |
| /* |
| * We need a region in CMOS to store the boot counter. |
| * |
| * This can either be declared as part of the option |
| * table or statically defined in the board config. |
| */ |
| #if CONFIG(USE_OPTION_TABLE) |
| # include "option_table.h" |
| # define BOOT_COUNT_CMOS_OFFSET (CMOS_VSTART_boot_count_offset >> 3) |
| #else |
| # if (CONFIG_ELOG_BOOT_COUNT_CMOS_OFFSET != 0) |
| # define BOOT_COUNT_CMOS_OFFSET CONFIG_ELOG_BOOT_COUNT_CMOS_OFFSET |
| # else |
| # error "Must configure CONFIG_ELOG_BOOT_COUNT_CMOS_OFFSET" |
| # endif |
| #endif |
| |
| #define BOOT_COUNT_SIGNATURE 0x4342 /* 'BC' */ |
| |
| struct boot_count { |
| u16 signature; |
| u32 count; |
| u16 checksum; |
| } __packed; |
| |
| /* Read and validate boot count structure from CMOS */ |
| static int boot_count_cmos_read(struct boot_count *bc) |
| { |
| u8 i, *p; |
| u16 csum; |
| |
| for (p = (u8*)bc, i = 0; i < sizeof(*bc); i++, p++) |
| *p = cmos_read(BOOT_COUNT_CMOS_OFFSET + i); |
| |
| /* Verify signature */ |
| if (bc->signature != BOOT_COUNT_SIGNATURE) { |
| printk(BIOS_DEBUG, "Boot Count invalid signature\n"); |
| return -1; |
| } |
| |
| /* Verify checksum over signature and counter only */ |
| csum = compute_ip_checksum(bc, offsetof(struct boot_count, checksum)); |
| |
| if (csum != bc->checksum) { |
| printk(BIOS_DEBUG, "Boot Count checksum mismatch\n"); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /* Write boot count structure to CMOS */ |
| static void boot_count_cmos_write(struct boot_count *bc) |
| { |
| u8 i, *p; |
| |
| /* Checksum over signature and counter only */ |
| bc->checksum = compute_ip_checksum( |
| bc, offsetof(struct boot_count, checksum)); |
| |
| for (p = (u8*)bc, i = 0; i < sizeof(*bc); i++, p++) |
| cmos_write(*p, BOOT_COUNT_CMOS_OFFSET + i); |
| } |
| |
| /* Increment boot count and return the new value */ |
| u32 boot_count_increment(void) |
| { |
| struct boot_count bc; |
| |
| /* Read and increment boot count */ |
| if (boot_count_cmos_read(&bc) < 0) { |
| /* Structure invalid, re-initialize */ |
| bc.signature = BOOT_COUNT_SIGNATURE; |
| bc.count = 0; |
| } |
| |
| /* Increment boot counter */ |
| bc.count++; |
| |
| /* Write the new count to CMOS */ |
| boot_count_cmos_write(&bc); |
| |
| printk(BIOS_DEBUG, "Boot Count incremented to %u\n", bc.count); |
| return bc.count; |
| } |
| |
| /* Return the current boot count */ |
| u32 boot_count_read(void) |
| { |
| struct boot_count bc; |
| |
| if (boot_count_cmos_read(&bc) < 0) |
| return 0; |
| |
| return bc.count; |
| } |