| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <assert.h> |
| #include <cbfs.h> |
| #include <console/console.h> |
| #include <delay.h> |
| #include <ec/google/chromeec/ec.h> |
| #include <halt.h> |
| #include <security/vboot/misc.h> |
| #include <security/vboot/vbnv.h> |
| #include <security/vboot/vboot_common.h> |
| #include <timer.h> |
| #include <timestamp.h> |
| #include <vb2_api.h> |
| |
| #define _EC_FILENAME(select, suffix) \ |
| (select == VB_SELECT_FIRMWARE_READONLY ? "ecro" suffix : "ecrw" suffix) |
| #define EC_IMAGE_FILENAME(select) _EC_FILENAME(select, "") |
| #define EC_HASH_FILENAME(select) _EC_FILENAME(select, ".hash") |
| |
| /* Wait 10 ms between attempts to check if EC's hash is ready */ |
| #define CROS_EC_HASH_CHECK_DELAY_MS 10 |
| /* Give the EC 2 seconds to finish calculating its hash */ |
| #define CROS_EC_HASH_TIMEOUT_MS 2000 |
| |
| /* Wait 3 seconds after software sync for EC to clear the limit power flag. */ |
| #define LIMIT_POWER_WAIT_TIMEOUT_MS 3000 |
| /* Check the limit power flag every 10 ms while waiting. */ |
| #define LIMIT_POWER_POLL_SLEEP_MS 10 |
| |
| /* Wait 3 seconds for EC to sysjump to RW */ |
| #define CROS_EC_SYSJUMP_TIMEOUT_MS 3000 |
| |
| /* |
| * The external API for EC software sync. This function calls into |
| * vboot, which kicks off the process. Vboot runs the verified boot |
| * logic, and requires the client program to provide callbacks which |
| * perform the work. |
| */ |
| void vboot_sync_ec(void) |
| { |
| vb2_error_t retval = VB2_SUCCESS; |
| struct vb2_context *ctx; |
| |
| timestamp_add_now(TS_EC_SYNC_START); |
| |
| ctx = vboot_get_context(); |
| ctx->flags |= VB2_CONTEXT_EC_SYNC_SUPPORTED; |
| |
| retval = vb2api_ec_sync(ctx); |
| vboot_save_data(ctx); |
| |
| switch (retval) { |
| case VB2_SUCCESS: |
| break; |
| |
| case VB2_REQUEST_REBOOT_EC_TO_RO: |
| printk(BIOS_INFO, "EC Reboot requested. Doing cold reboot\n"); |
| if (google_chromeec_reboot(EC_REBOOT_COLD, 0)) |
| printk(BIOS_EMERG, "Failed to get EC to cold reboot\n"); |
| |
| halt(); |
| break; |
| |
| /* Only for EC-EFS */ |
| case VB2_REQUEST_REBOOT_EC_SWITCH_RW: |
| printk(BIOS_INFO, "Switch EC slot requested. Doing cold reboot\n"); |
| if (google_chromeec_reboot(EC_REBOOT_COLD, |
| EC_REBOOT_FLAG_SWITCH_RW_SLOT)) |
| printk(BIOS_EMERG, "Failed to get EC to cold reboot\n"); |
| |
| halt(); |
| break; |
| |
| case VB2_REQUEST_REBOOT: |
| printk(BIOS_INFO, "Reboot requested. Doing warm reboot\n"); |
| vboot_reboot(); |
| break; |
| |
| default: |
| printk(BIOS_ERR, "EC software sync failed (%#x)," |
| " rebooting\n", retval); |
| vboot_reboot(); |
| break; |
| } |
| |
| timestamp_add_now(TS_EC_SYNC_END); |
| } |
| |
| /* Convert firmware image type into a flash offset */ |
| static uint32_t get_vboot_hash_offset(enum vb2_firmware_selection select) |
| { |
| switch (select) { |
| case VB_SELECT_FIRMWARE_READONLY: |
| return EC_VBOOT_HASH_OFFSET_RO; |
| case VB_SELECT_FIRMWARE_EC_UPDATE: |
| return EC_VBOOT_HASH_OFFSET_UPDATE; |
| default: |
| return EC_VBOOT_HASH_OFFSET_ACTIVE; |
| } |
| } |
| |
| /* |
| * Asks the EC to calculate a hash of the specified firmware image, and |
| * returns the information in **hash and *hash_size. |
| */ |
| static vb2_error_t ec_hash_image(enum vb2_firmware_selection select, |
| const uint8_t **hash, int *hash_size) |
| { |
| static struct ec_response_vboot_hash resp; |
| uint32_t hash_offset; |
| int recalc_requested = 0; |
| struct stopwatch sw; |
| |
| hash_offset = get_vboot_hash_offset(select); |
| |
| stopwatch_init_msecs_expire(&sw, CROS_EC_HASH_TIMEOUT_MS); |
| do { |
| if (google_chromeec_get_vboot_hash(hash_offset, &resp)) |
| return VB2_ERROR_UNKNOWN; |
| |
| switch (resp.status) { |
| case EC_VBOOT_HASH_STATUS_NONE: |
| /* |
| * There is no hash available right now. |
| * Request a recalc if it hasn't been done yet. |
| */ |
| if (recalc_requested) |
| break; |
| |
| printk(BIOS_WARNING, |
| "%s: No valid hash (status=%d size=%d). " |
| "Computing...\n", __func__, resp.status, |
| resp.size); |
| |
| if (google_chromeec_start_vboot_hash( |
| EC_VBOOT_HASH_TYPE_SHA256, hash_offset, &resp)) |
| return VB2_ERROR_UNKNOWN; |
| |
| recalc_requested = 1; |
| |
| /* |
| * Expect status to be busy since we just sent |
| * a recalc request. |
| */ |
| resp.status = EC_VBOOT_HASH_STATUS_BUSY; |
| |
| /* Hash just started calculating, let it go for a bit */ |
| mdelay(CROS_EC_HASH_CHECK_DELAY_MS); |
| break; |
| |
| case EC_VBOOT_HASH_STATUS_BUSY: |
| /* Hash is still calculating. */ |
| mdelay(CROS_EC_HASH_CHECK_DELAY_MS); |
| break; |
| |
| case EC_VBOOT_HASH_STATUS_DONE: /* intentional fallthrough */ |
| default: |
| /* Hash is ready! */ |
| break; |
| } |
| } while (resp.status == EC_VBOOT_HASH_STATUS_BUSY && |
| !stopwatch_expired(&sw)); |
| |
| timestamp_add_now(TS_EC_HASH_READY); |
| |
| if (resp.status != EC_VBOOT_HASH_STATUS_DONE) { |
| printk(BIOS_ERR, "%s: Hash status not done: %d\n", __func__, |
| resp.status); |
| return VB2_ERROR_UNKNOWN; |
| } |
| if (resp.hash_type != EC_VBOOT_HASH_TYPE_SHA256) { |
| printk(BIOS_ERR, "EC hash was the wrong type.\n"); |
| return VB2_ERROR_UNKNOWN; |
| } |
| |
| printk(BIOS_INFO, "EC took %lldus to calculate image hash\n", |
| stopwatch_duration_usecs(&sw)); |
| |
| *hash = resp.hash_digest; |
| *hash_size = resp.digest_size; |
| |
| return VB2_SUCCESS; |
| } |
| |
| /* |
| * Asks the EC to protect or unprotect the specified flash region. |
| */ |
| static vb2_error_t ec_protect_flash(int enable) |
| { |
| struct ec_response_flash_protect resp; |
| uint32_t protected_region = EC_FLASH_PROTECT_ALL_NOW; |
| const uint32_t mask = EC_FLASH_PROTECT_ALL_NOW | EC_FLASH_PROTECT_ALL_AT_BOOT; |
| |
| if (google_chromeec_flash_protect(mask, enable ? mask : 0, &resp) != 0) |
| return VB2_ERROR_UNKNOWN; |
| |
| if (!enable) { |
| /* If protection is still enabled, need reboot */ |
| if (resp.flags & protected_region) |
| return VB2_REQUEST_REBOOT_EC_TO_RO; |
| |
| return VB2_SUCCESS; |
| } |
| |
| /* |
| * If write protect and ro-at-boot aren't both asserted, don't expect |
| * protection enabled. |
| */ |
| if ((~resp.flags) & (EC_FLASH_PROTECT_GPIO_ASSERTED | |
| EC_FLASH_PROTECT_RO_AT_BOOT)) |
| return VB2_SUCCESS; |
| |
| /* If flash is protected now, success */ |
| if (resp.flags & EC_FLASH_PROTECT_ALL_NOW) |
| return VB2_SUCCESS; |
| |
| /* If RW will be protected at boot but not now, need a reboot */ |
| if (resp.flags & EC_FLASH_PROTECT_ALL_AT_BOOT) |
| return VB2_REQUEST_REBOOT_EC_TO_RO; |
| |
| /* Otherwise, it's an error */ |
| return VB2_ERROR_UNKNOWN; |
| } |
| |
| /* Convert a firmware image type to an EC flash region */ |
| static enum ec_flash_region vboot_to_ec_region(enum vb2_firmware_selection select) |
| { |
| switch (select) { |
| case VB_SELECT_FIRMWARE_READONLY: |
| return EC_FLASH_REGION_WP_RO; |
| case VB_SELECT_FIRMWARE_EC_UPDATE: |
| return EC_FLASH_REGION_UPDATE; |
| default: |
| return EC_FLASH_REGION_ACTIVE; |
| } |
| } |
| |
| /* |
| * Send an image to the EC in burst-sized chunks. |
| */ |
| static vb2_error_t ec_flash_write(void *image, uint32_t region_offset, |
| int image_size) |
| { |
| struct ec_response_get_protocol_info resp_proto; |
| struct ec_response_flash_info resp_flash; |
| ssize_t pdata_max_size; |
| ssize_t burst; |
| uint8_t *file_buf; |
| struct ec_params_flash_write *params; |
| uint32_t end, off; |
| |
| /* |
| * Get EC's protocol information, so that we can figure out how much |
| * data can be sent in one message. |
| */ |
| if (google_chromeec_get_protocol_info(&resp_proto)) { |
| printk(BIOS_ERR, "Failed to get EC protocol information; " |
| "skipping flash write\n"); |
| return VB2_ERROR_UNKNOWN; |
| } |
| |
| /* |
| * Determine burst size. This must be a multiple of the write block |
| * size, and must also fit into the host parameter buffer. |
| */ |
| if (google_chromeec_flash_info(&resp_flash)) { |
| printk(BIOS_ERR, "Failed to get EC flash information; " |
| "skipping flash write\n"); |
| return VB2_ERROR_UNKNOWN; |
| } |
| |
| /* Limit the potential buffer stack allocation to 1K */ |
| pdata_max_size = MIN(1024, resp_proto.max_request_packet_size - |
| sizeof(struct ec_host_request)); |
| |
| /* Round burst to a multiple of the flash write block size */ |
| burst = pdata_max_size - sizeof(*params); |
| burst = (burst / resp_flash.write_block_size) * |
| resp_flash.write_block_size; |
| |
| /* Buffer too small */ |
| if (burst <= 0) { |
| printk(BIOS_ERR, "Flash write buffer too small! skipping " |
| "flash write\n"); |
| return VB2_ERROR_UNKNOWN; |
| } |
| |
| /* Allocate buffer on the stack */ |
| params = alloca(burst + sizeof(*params)); |
| |
| /* Fill up the buffer */ |
| end = region_offset + image_size; |
| file_buf = image; |
| for (off = region_offset; off < end; off += burst) { |
| uint32_t todo = MIN(end - off, burst); |
| uint32_t xfer_size = todo + sizeof(*params); |
| |
| params->offset = off; |
| params->size = todo; |
| |
| /* Read todo bytes into the buffer */ |
| memcpy(params + 1, file_buf, todo); |
| |
| /* Make sure to add back in the size of the parameters */ |
| if (google_chromeec_flash_write_block( |
| (const uint8_t *)params, xfer_size)) { |
| printk(BIOS_ERR, "EC failed flash write command, " |
| "relative offset %u!\n", off - region_offset); |
| return VB2_ERROR_UNKNOWN; |
| } |
| |
| file_buf += todo; |
| } |
| |
| return VB2_SUCCESS; |
| } |
| |
| /* |
| * The logic for updating an EC firmware image. |
| */ |
| static vb2_error_t ec_update_image(enum vb2_firmware_selection select) |
| { |
| uint32_t region_offset, region_size; |
| enum ec_flash_region region; |
| vb2_error_t rv; |
| void *image; |
| size_t image_size; |
| |
| /* Un-protect the flash region */ |
| rv = ec_protect_flash(0); |
| if (rv != VB2_SUCCESS) |
| return rv; |
| |
| /* Convert vboot region into an EC region */ |
| region = vboot_to_ec_region(select); |
| |
| /* Get information about the flash region */ |
| if (google_chromeec_flash_region_info(region, ®ion_offset, |
| ®ion_size)) |
| return VB2_ERROR_UNKNOWN; |
| |
| /* Map the CBFS file */ |
| image = cbfs_map(EC_IMAGE_FILENAME(select), &image_size); |
| if (!image) |
| return VB2_ERROR_UNKNOWN; |
| |
| rv = VB2_ERROR_UNKNOWN; |
| |
| /* Bail if the image is too large */ |
| if (image_size > region_size) |
| goto unmap; |
| |
| /* Erase the region */ |
| if (google_chromeec_flash_erase(region_offset, region_size)) |
| goto unmap; |
| |
| /* Write the image into the region */ |
| if (ec_flash_write(image, region_offset, image_size)) |
| goto unmap; |
| |
| /* Verify the image */ |
| if (google_chromeec_efs_verify(region)) |
| goto unmap; |
| |
| rv = VB2_SUCCESS; |
| |
| unmap: |
| cbfs_unmap(image); |
| return rv; |
| } |
| |
| static vb2_error_t ec_get_expected_hash(enum vb2_firmware_selection select, |
| const uint8_t **hash, |
| int *hash_size) |
| { |
| size_t size; |
| const char *filename = EC_HASH_FILENAME(select); |
| |
| /* vboot has no API to return this memory, so must permanently leak a mapping here. */ |
| const uint8_t *file = cbfs_map(filename, &size); |
| |
| if (!file) |
| return VB2_ERROR_UNKNOWN; |
| |
| *hash = file; |
| *hash_size = (int)size; |
| |
| return VB2_SUCCESS; |
| } |
| |
| /*********************************************************************** |
| * Vboot Callbacks |
| ***********************************************************************/ |
| |
| /* |
| * Write opaque data into NV storage region. |
| */ |
| vb2_error_t vb2ex_commit_data(struct vb2_context *ctx) |
| { |
| save_vbnv(ctx->nvdata); |
| return VB2_SUCCESS; |
| } |
| |
| /* |
| * Report whether the EC is in RW or not. |
| */ |
| vb2_error_t vb2ex_ec_running_rw(int *in_rw) |
| { |
| *in_rw = !google_ec_running_ro(); |
| return VB2_SUCCESS; |
| } |
| |
| /* |
| * Callback for when Vboot is finished. |
| */ |
| vb2_error_t vb2ex_ec_vboot_done(struct vb2_context *ctx) |
| { |
| int limit_power = 0; |
| bool message_printed = false; |
| struct stopwatch sw; |
| int in_recovery = !!(ctx->flags & VB2_CONTEXT_RECOVERY_MODE); |
| |
| /* |
| * Do not wait for the limit power flag to be cleared in |
| * recovery mode since we didn't just sysjump. |
| */ |
| if (in_recovery) |
| return VB2_SUCCESS; |
| |
| timestamp_add_now(TS_EC_POWER_LIMIT_WAIT); |
| |
| stopwatch_init_msecs_expire(&sw, LIMIT_POWER_WAIT_TIMEOUT_MS); |
| |
| /* Ensure we have enough power to continue booting. */ |
| while (1) { |
| if (google_chromeec_read_limit_power_request(&limit_power)) { |
| printk(BIOS_ERR, "Failed to check EC limit power" |
| "flag.\n"); |
| return VB2_ERROR_UNKNOWN; |
| } |
| |
| if (!limit_power || stopwatch_expired(&sw)) |
| break; |
| |
| if (!message_printed) { |
| printk(BIOS_SPEW, |
| "Waiting for EC to clear limit power flag.\n"); |
| message_printed = true; |
| } |
| |
| mdelay(LIMIT_POWER_POLL_SLEEP_MS); |
| } |
| |
| if (limit_power) { |
| printk(BIOS_INFO, |
| "EC requests limited power usage. Request shutdown.\n"); |
| return VB2_REQUEST_SHUTDOWN; |
| } else { |
| printk(BIOS_INFO, "Waited %lldus to clear limit power flag.\n", |
| stopwatch_duration_usecs(&sw)); |
| } |
| |
| return VB2_SUCCESS; |
| } |
| |
| /* |
| * Support battery cutoff if required. |
| */ |
| vb2_error_t vb2ex_ec_battery_cutoff(void) |
| { |
| if (google_chromeec_battery_cutoff(EC_BATTERY_CUTOFF_FLAG_AT_SHUTDOWN)) |
| return VB2_ERROR_UNKNOWN; |
| |
| return VB2_SUCCESS; |
| } |
| |
| /* |
| * Vboot callback for calculating an EC image's hash. |
| */ |
| vb2_error_t vb2ex_ec_hash_image(enum vb2_firmware_selection select, |
| const uint8_t **hash, int *hash_size) |
| { |
| return ec_hash_image(select, hash, hash_size); |
| } |
| |
| /* |
| * Vboot callback for EC flash protection. |
| */ |
| vb2_error_t vb2ex_ec_protect(void) |
| { |
| return ec_protect_flash(1); |
| } |
| |
| /* |
| * Get hash for image. |
| */ |
| vb2_error_t vb2ex_ec_get_expected_image_hash(enum vb2_firmware_selection select, |
| const uint8_t **hash, |
| int *hash_size) |
| { |
| return ec_get_expected_hash(select, hash, hash_size); |
| } |
| |
| /* |
| * Disable further sysjumps (i.e., stay in RW until next reboot) |
| */ |
| vb2_error_t vb2ex_ec_disable_jump(void) |
| { |
| if (google_chromeec_reboot(EC_REBOOT_DISABLE_JUMP, 0)) |
| return VB2_ERROR_UNKNOWN; |
| |
| return VB2_SUCCESS; |
| } |
| |
| /* |
| * Update EC image. |
| */ |
| vb2_error_t vb2ex_ec_update_image(enum vb2_firmware_selection select) |
| { |
| return ec_update_image(select); |
| } |
| |
| /* |
| * Vboot callback for commanding EC to sysjump to RW. |
| */ |
| vb2_error_t vb2ex_ec_jump_to_rw(void) |
| { |
| struct stopwatch sw; |
| |
| if (google_chromeec_reboot(EC_REBOOT_JUMP_RW, 0)) |
| return VB2_ERROR_UNKNOWN; |
| |
| /* Give the EC 3 seconds to sysjump */ |
| stopwatch_init_msecs_expire(&sw, CROS_EC_SYSJUMP_TIMEOUT_MS); |
| |
| /* Default delay to wait after EC reboot */ |
| mdelay(50); |
| while (google_chromeec_hello()) { |
| if (stopwatch_expired(&sw)) { |
| printk(BIOS_ERR, "EC did not return from reboot after %lldus\n", |
| stopwatch_duration_usecs(&sw)); |
| return VB2_ERROR_UNKNOWN; |
| } |
| |
| mdelay(5); |
| } |
| |
| printk(BIOS_INFO, "\nEC returned from reboot after %lldus\n", |
| stopwatch_duration_usecs(&sw)); |
| |
| return VB2_SUCCESS; |
| } |