diff options
Diffstat (limited to 'futility/updater_quirks.c')
| -rw-r--r-- | futility/updater_quirks.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/futility/updater_quirks.c b/futility/updater_quirks.c new file mode 100644 index 00000000..df3c9983 --- /dev/null +++ b/futility/updater_quirks.c @@ -0,0 +1,147 @@ +/* + * Copyright 2018 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + * + * The board-specific quirks needed by firmware updater. + */ + +#include <assert.h> +#include <stdio.h> + +#include "updater.h" +#include "host_misc.h" + +/* + * Helper function to write a firmware image into file on disk. + * Returns the result from vb2_write_file. + */ +static int write_image(const char *file_path, struct firmware_image *image) +{ + return vb2_write_file(file_path, image->data, image->size); +} + +/* Preserves meta data and reload image contents from given file path. */ +static int reload_image(const char *file_path, struct firmware_image *image) +{ + const char *programmer = image->programmer; + free_image(image); + image->programmer = programmer; + return load_image(file_path, image); +} + +/* + * Quirk to enlarge a firmware image to match flash size. This is needed by + * devices using multiple SPI flash with different sizes, for example 8M and + * 16M. The image_to will be padded with 0xFF using the size of image_from. + * Returns 0 on success, otherwise failure. + */ +static int quirk_enlarge_image(struct updater_config *cfg) +{ + struct firmware_image *image_from = &cfg->image_current, + *image_to = &cfg->image; + const char *tmp_path; + size_t to_write; + FILE *fp; + + if (image_from->size <= image_to->size) + return 0; + + tmp_path = create_temp_file(cfg); + if (!tmp_path) + return -1; + + DEBUG("Resize image from %u to %u.", image_to->size, image_from->size); + to_write = image_from->size - image_to->size; + write_image(tmp_path, image_to); + fp = fopen(tmp_path, "ab"); + if (!fp) { + ERROR("Cannot open temporary file %s.", tmp_path); + return -1; + } + while (to_write-- > 0) + fputc('\xff', fp); + fclose(fp); + return reload_image(tmp_path, image_to); +} + +/* + * Quirk to unlock a firmware image with SI_ME (management engine) when updating + * so the system has a chance to make sure SI_ME won't be corrupted on next boot + * before locking the Flash Master values in SI_DESC. + * Returns 0 on success, otherwise failure. + */ +static int quirk_unlock_me_for_update(struct updater_config *cfg) +{ + struct firmware_section section; + struct firmware_image *image_to = &cfg->image; + const int flash_master_offset = 128; + const uint8_t flash_master[] = { + 0x00, 0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, 0xff, + 0xff, 0xff + }; + + find_firmware_section(§ion, image_to, FMAP_SI_DESC); + if (section.size < flash_master_offset + ARRAY_SIZE(flash_master)) + return 0; + if (memcmp(section.data + flash_master_offset, flash_master, + ARRAY_SIZE(flash_master)) == 0) { + DEBUG("Target ME not locked."); + return 0; + } + /* + * b/35568719: We should only update with unlocked ME and let + * board-postinst lock it. + */ + printf("%s: Changed Flash Master Values to unlocked.\n", __FUNCTION__); + memcpy(section.data + flash_master_offset, flash_master, + ARRAY_SIZE(flash_master)); + return 0; +} + +/* + * Checks and returns 0 if the platform version of current system is larger + * or equal to given number, otherwise non-zero. + */ +static int quirk_min_platform_version(struct updater_config *cfg) +{ + int min_version = get_config_quirk(QUIRK_MIN_PLATFORM_VERSION, cfg); + int platform_version = get_system_property(SYS_PROP_PLATFORM_VER, cfg); + + DEBUG("Minimum required version=%d, current platform version=%d", + min_version, platform_version); + + if (platform_version >= min_version) + return 0; + ERROR("Need platform version >= %d (current is %d). " + "This firmware will only run on newer systems.", + min_version, platform_version); + return -1; +} + +/* + * Registers known quirks to a updater_config object. + */ +void updater_register_quirks(struct updater_config *cfg) +{ + struct quirk_entry *quirks; + + assert(ARRAY_SIZE(cfg->quirks) == QUIRK_MAX); + quirks = &cfg->quirks[QUIRK_ENLARGE_IMAGE]; + quirks->name = "enlarge_image"; + quirks->help = "Enlarge firmware image by flash size."; + quirks->apply = quirk_enlarge_image; + + quirks = &cfg->quirks[QUIRK_MIN_PLATFORM_VERSION]; + quirks->name = "min_platform_version"; + quirks->help = "Minimum compatible platform version " + "(also known as Board ID version)."; + quirks->apply = quirk_min_platform_version; + + quirks = &cfg->quirks[QUIRK_UNLOCK_ME_FOR_UPDATE]; + quirks->name = "unlock_me_for_update"; + quirks->help = "b/35568719; only lock management engine in " + "board-postinst."; + quirks->apply = quirk_unlock_me_for_update; + +} |