vboot_storage.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <assert.h>
#include <console/console.h>
#include <ec/google/chromeec/ec.h>
#include <security/vboot/vboot_common.h>
 
#define VBOOT_HASH_VSLOT 0
#define VBOOT_HASH_VSLOT_MASK (1 << (VBOOT_HASH_VSLOT))
 
int vboot_save_hash(void *digest, size_t digest_size)
{
        const int slot = VBOOT_HASH_VSLOT;
        uint32_t lock_status;
        int num_slots;
 
        /* Ensure the digests being saved match the EC's slot size. */
        assert(digest_size == EC_VSTORE_SLOT_SIZE);
 
        if (google_chromeec_vstore_write(slot, digest, digest_size))
                return -1;
 
        /* Assert the slot is locked on successful write. */
        num_slots = google_chromeec_vstore_info(&lock_status);
 
        /* Normalize to be 0 based. If num_slots returned 0 then it'll be -1. */
        num_slots--;
 
        if (num_slots < slot) {
                printk(BIOS_ERR, "Not enough vstore slots for vboot hash: %d\n",
                        num_slots + 1);
                return -1;
        }
 
        if ((lock_status & VBOOT_HASH_VSLOT_MASK) == 0) {
                printk(BIOS_ERR, "Vstore slot not locked after write.\n");
                return -1;
        }
 
        return 0;
}
 
int vboot_retrieve_hash(void *digest, size_t digest_size)
{
        /* Ensure the digests being saved match the EC's slot size. */
        assert(digest_size == EC_VSTORE_SLOT_SIZE);
 
        return google_chromeec_vstore_read(VBOOT_HASH_VSLOT, digest);
}