diff options
Diffstat (limited to 'src/vendorcode/google/chromeos/vboot2/vboot_logic.c')
-rw-r--r-- | src/vendorcode/google/chromeos/vboot2/vboot_logic.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/src/vendorcode/google/chromeos/vboot2/vboot_logic.c b/src/vendorcode/google/chromeos/vboot2/vboot_logic.c new file mode 100644 index 0000000000..76355ecdab --- /dev/null +++ b/src/vendorcode/google/chromeos/vboot2/vboot_logic.c @@ -0,0 +1,352 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2014 Google Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc. + */ + +#include <antirollback.h> +#include <arch/exception.h> +#include <assert.h> +#include <console/console.h> +#include <console/vtxprintf.h> +#include <delay.h> +#include <string.h> +#include <timestamp.h> +#include <vb2_api.h> + +#include "../chromeos.h" +#include "misc.h" + +#define TODO_BLOCK_SIZE 1024 + +static int is_slot_a(struct vb2_context *ctx) +{ + return !(ctx->flags & VB2_CONTEXT_FW_SLOT_B); +} + +/* exports */ + +void vb2ex_printf(const char *func, const char *fmt, ...) +{ + va_list args; + + printk(BIOS_INFO, "VB2:%s() ", func); + va_start(args, fmt); + do_printk_va_list(BIOS_INFO, fmt, args); + va_end(args); + + return; +} + +int vb2ex_tpm_clear_owner(struct vb2_context *ctx) +{ + uint32_t rv; + printk(BIOS_INFO, "Clearing TPM owner\n"); + rv = tpm_clear_and_reenable(); + if (rv) + return VB2_ERROR_EX_TPM_CLEAR_OWNER; + return VB2_SUCCESS; +} + +int vb2ex_read_resource(struct vb2_context *ctx, + enum vb2_resource_index index, + uint32_t offset, + void *buf, + uint32_t size) +{ + struct region_device rdev; + const char *name; + + switch (index) { + case VB2_RES_GBB: + name = "GBB"; + break; + case VB2_RES_FW_VBLOCK: + if (is_slot_a(ctx)) + name = "VBLOCK_A"; + else + name = "VBLOCK_B"; + break; + default: + return VB2_ERROR_EX_READ_RESOURCE_INDEX; + } + + if (vboot_named_region_device(name, &rdev)) + return VB2_ERROR_EX_READ_RESOURCE_SIZE; + + if (rdev_readat(&rdev, buf, offset, size) != size) + return VB2_ERROR_EX_READ_RESOURCE_SIZE; + + return VB2_SUCCESS; +} + +/* No-op stubs that can be overridden by SoCs with hardware crypto support. */ +__attribute__((weak)) +int vb2ex_hwcrypto_digest_init(enum vb2_hash_algorithm hash_alg, + uint32_t data_size) +{ + return VB2_ERROR_EX_HWCRYPTO_UNSUPPORTED; +} + +__attribute__((weak)) +int vb2ex_hwcrypto_digest_extend(const uint8_t *buf, uint32_t size) +{ + BUG(); /* Should never get called if init() returned an error. */ + return VB2_ERROR_UNKNOWN; +} + +__attribute__((weak)) +int vb2ex_hwcrypto_digest_finalize(uint8_t *digest, uint32_t digest_size) +{ + BUG(); /* Should never get called if init() returned an error. */ + return VB2_ERROR_UNKNOWN; +} + +static int hash_body(struct vb2_context *ctx, struct region_device *fw_main) +{ + uint64_t load_ts; + uint32_t expected_size; + uint8_t block[TODO_BLOCK_SIZE]; + size_t block_size = sizeof(block); + size_t offset; + int rv; + + /* + * Since loading the firmware and calculating its hash is intertwined, + * we use this little trick to measure them separately and pretend it + * was first loaded and then hashed in one piece with the timestamps. + * (This split won't make sense with memory-mapped media like on x86.) + */ + load_ts = timestamp_get(); + timestamp_add(TS_START_HASH_BODY, load_ts); + + expected_size = region_device_sz(fw_main); + offset = 0; + + /* Start the body hash */ + rv = vb2api_init_hash(ctx, VB2_HASH_TAG_FW_BODY, &expected_size); + if (rv) + return rv; + + /* Extend over the body */ + while (expected_size) { + uint64_t temp_ts; + if (block_size > expected_size) + block_size = expected_size; + + temp_ts = timestamp_get(); + if (rdev_readat(fw_main, block, offset, block_size) < 0) + return VB2_ERROR_UNKNOWN; + load_ts += timestamp_get() - temp_ts; + + rv = vb2api_extend_hash(ctx, block, block_size); + if (rv) + return rv; + + expected_size -= block_size; + offset += block_size; + } + + timestamp_add(TS_DONE_LOADING, load_ts); + timestamp_add_now(TS_DONE_HASHING); + + /* Check the result (with RSA signature verification) */ + rv = vb2api_check_hash(ctx); + if (rv) + return rv; + + timestamp_add_now(TS_END_HASH_BODY); + + return VB2_SUCCESS; +} + +static int locate_firmware(struct vb2_context *ctx, + struct region_device *fw_main) +{ + const char *name; + + if (is_slot_a(ctx)) + name = "FW_MAIN_A"; + else + name = "FW_MAIN_B"; + + return vboot_named_region_device(name, fw_main); +} + +/** + * Save non-volatile and/or secure data if needed. + */ +static void save_if_needed(struct vb2_context *ctx) +{ + if (ctx->flags & VB2_CONTEXT_NVDATA_CHANGED) { + printk(BIOS_INFO, "Saving nvdata\n"); + save_vbnv(ctx->nvdata); + ctx->flags &= ~VB2_CONTEXT_NVDATA_CHANGED; + } + if (ctx->flags & VB2_CONTEXT_SECDATA_CHANGED) { + printk(BIOS_INFO, "Saving secdata\n"); + antirollback_write_space_firmware(ctx); + ctx->flags &= ~VB2_CONTEXT_SECDATA_CHANGED; + } +} + +static uint32_t extend_pcrs(struct vb2_context *ctx) +{ + return tpm_extend_pcr(ctx, 0, BOOT_MODE_PCR) || + tpm_extend_pcr(ctx, 1, HWID_DIGEST_PCR); +} + +static void init_vb2_working_data(void) +{ + struct vb2_working_data *wd; + size_t work_size; + + work_size = vb2_working_data_size(); + wd = vboot_get_working_data(); + memset(wd, 0, work_size); + /* + * vboot prefers 16-byte alignment. This takes away 16 bytes + * from the VBOOT2_WORK region, but the vboot devs said that's okay. + */ + wd->buffer_offset = ALIGN_UP(sizeof(*wd), 16); + wd->buffer_size = work_size - wd->buffer_offset; +} + +/** + * Verify and select the firmware in the RW image + * + * TODO: Avoid loading a stage twice (once in hash_body & again in load_stage). + * when per-stage verification is ready. + */ +void verstage_main(void) +{ + struct vb2_context ctx; + struct region_device fw_main; + struct vb2_working_data *wd; + int rv; + init_vb2_working_data(); + wd = vboot_get_working_data(); + timestamp_add_now(TS_START_VBOOT); + + /* Set up context and work buffer */ + memset(&ctx, 0, sizeof(ctx)); + ctx.workbuf = vboot_get_work_buffer(wd); + ctx.workbuf_size = wd->buffer_size; + + /* Read nvdata from a non-volatile storage */ + read_vbnv(ctx.nvdata); + + /* Read secdata from TPM. Initialize TPM if secdata not found. We don't + * check the return value here because vb2api_fw_phase1 will catch + * invalid secdata and tell us what to do (=reboot). */ + timestamp_add_now(TS_START_TPMINIT); + antirollback_read_space_firmware(&ctx); + timestamp_add_now(TS_END_TPMINIT); + + if (!IS_ENABLED(CONFIG_VIRTUAL_DEV_SWITCH) && + get_developer_mode_switch()) + ctx.flags |= VB2_CONTEXT_FORCE_DEVELOPER_MODE; + + if (get_recovery_mode_switch()) { + clear_recovery_mode_switch(); + ctx.flags |= VB2_CONTEXT_FORCE_RECOVERY_MODE; + if (IS_ENABLED(CONFIG_VBOOT_DISABLE_DEV_ON_RECOVERY)) + ctx.flags |= VB2_DISABLE_DEVELOPER_MODE; + } + + if (IS_ENABLED(CONFIG_WIPEOUT_SUPPORTED) && get_wipeout_mode_switch()) + ctx.flags |= VB2_CONTEXT_FORCE_WIPEOUT_MODE; + + if (IS_ENABLED(CONFIG_LID_SWITCH) && !get_lid_switch()) + ctx.flags |= VB2_CONTEXT_NOFAIL_BOOT; + + /* Do early init (set up secdata and NVRAM, load GBB) */ + printk(BIOS_INFO, "Phase 1\n"); + rv = vb2api_fw_phase1(&ctx); + + if (rv) { + /* + * If vb2api_fw_phase1 fails, check for return value. + * If it is set to VB2_ERROR_API_PHASE1_RECOVERY, then continue + * into recovery mode. + * For any other error code, save context if needed and reboot. + */ + if (rv == VB2_ERROR_API_PHASE1_RECOVERY) { + printk(BIOS_INFO, "Recovery requested (%x)\n", rv); + save_if_needed(&ctx); + extend_pcrs(&ctx); /* ignore failures */ + timestamp_add_now(TS_END_VBOOT); + return; + } + + printk(BIOS_INFO, "Reboot reqested (%x)\n", rv); + save_if_needed(&ctx); + vboot_reboot(); + } + + /* Determine which firmware slot to boot (based on NVRAM) */ + printk(BIOS_INFO, "Phase 2\n"); + rv = vb2api_fw_phase2(&ctx); + if (rv) { + printk(BIOS_INFO, "Reboot requested (%x)\n", rv); + save_if_needed(&ctx); + vboot_reboot(); + } + + /* Try that slot (verify its keyblock and preamble) */ + printk(BIOS_INFO, "Phase 3\n"); + timestamp_add_now(TS_START_VERIFY_SLOT); + rv = vb2api_fw_phase3(&ctx); + timestamp_add_now(TS_END_VERIFY_SLOT); + if (rv) { + printk(BIOS_INFO, "Reboot requested (%x)\n", rv); + save_if_needed(&ctx); + vboot_reboot(); + } + + printk(BIOS_INFO, "Phase 4\n"); + rv = locate_firmware(&ctx, &fw_main); + if (rv) + die("Failed to read FMAP to locate firmware"); + + rv = hash_body(&ctx, &fw_main); + save_if_needed(&ctx); + if (rv) { + printk(BIOS_INFO, "Reboot requested (%x)\n", rv); + vboot_reboot(); + } + + rv = extend_pcrs(&ctx); + if (rv) { + printk(BIOS_WARNING, "Failed to extend TPM PCRs (%#x)\n", rv); + vb2api_fail(&ctx, VB2_RECOVERY_RO_TPM_U_ERROR, rv); + save_if_needed(&ctx); + vboot_reboot(); + } + + /* Lock TPM */ + rv = antirollback_lock_space_firmware(); + if (rv) { + printk(BIOS_INFO, "Failed to lock TPM (%x)\n", rv); + vb2api_fail(&ctx, VB2_RECOVERY_RO_TPM_L_ERROR, 0); + save_if_needed(&ctx); + vboot_reboot(); + } + + printk(BIOS_INFO, "Slot %c is selected\n", is_slot_a(&ctx) ? 'A' : 'B'); + vb2_set_selected_region(wd, &fw_main); + timestamp_add_now(TS_END_VBOOT); +} |