/* * This file is part of the coreboot project. * * Copyright 2015 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. */ #include <arch/early_variables.h> #include <cbfs.h> #include <console/console.h> #include <ec/google/chromeec/ec.h> #include <rmodule.h> #include <security/vboot/misc.h> #include <security/vboot/symbols.h> #include <security/vboot/vboot_common.h> /* Ensure vboot configuration is valid: */ _Static_assert(CONFIG(VBOOT_STARTS_IN_BOOTBLOCK) + CONFIG(VBOOT_STARTS_IN_ROMSTAGE) == 1, "vboot must either start in bootblock or romstage (not both!)"); _Static_assert(CONFIG(VBOOT_STARTS_IN_BOOTBLOCK) || !CONFIG(VBOOT_MIGRATE_WORKING_DATA), "no need to migrate working data after CBMEM is already up!"); _Static_assert(!CONFIG(VBOOT_SEPARATE_VERSTAGE) || CONFIG(VBOOT_STARTS_IN_BOOTBLOCK), "stand-alone verstage must start in (i.e. after) bootblock"); _Static_assert(!CONFIG(VBOOT_RETURN_FROM_VERSTAGE) || CONFIG(VBOOT_SEPARATE_VERSTAGE), "return from verstage only makes sense for separate verstages"); /* The stage loading code is compiled and entered from multiple stages. The * helper functions below attempt to provide more clarity on when certain * code should be called. */ static int verification_should_run(void) { if (CONFIG(VBOOT_SEPARATE_VERSTAGE)) return ENV_VERSTAGE; else if (CONFIG(VBOOT_STARTS_IN_ROMSTAGE)) return ENV_ROMSTAGE; else if (CONFIG(VBOOT_STARTS_IN_BOOTBLOCK)) return ENV_BOOTBLOCK; else die("impossible!"); } static int verstage_should_load(void) { if (CONFIG(VBOOT_SEPARATE_VERSTAGE)) return ENV_BOOTBLOCK; else return 0; } static int vboot_executed CAR_GLOBAL; int vboot_logic_executed(void) { /* If we are in a stage that would load the verstage or execute the vboot logic directly, we store the answer in a global. */ if (verstage_should_load() || verification_should_run()) return car_get_var(vboot_executed); if (CONFIG(VBOOT_STARTS_IN_BOOTBLOCK)) { /* All other stages are "after the bootblock" */ return !ENV_BOOTBLOCK; } else if (CONFIG(VBOOT_STARTS_IN_ROMSTAGE)) { /* Post-RAM stages are "after the romstage" */ #ifdef __PRE_RAM__ return 0; #else return 1; #endif } else { die("impossible!"); } } static void vboot_prepare(void) { if (verification_should_run()) { /* Note: this path is not used for VBOOT_RETURN_FROM_VERSTAGE */ verstage_main(); car_set_var(vboot_executed, 1); vboot_save_recovery_reason_vbnv(); } else if (verstage_should_load()) { struct cbfsf file; struct prog verstage = PROG_INIT(PROG_VERSTAGE, CONFIG_CBFS_PREFIX "/verstage"); printk(BIOS_DEBUG, "VBOOT: Loading verstage.\n"); /* load verstage from RO */ if (cbfs_boot_locate(&file, prog_name(&verstage), NULL)) die("failed to load verstage"); cbfs_file_data(prog_rdev(&verstage), &file); if (cbfs_prog_stage_load(&verstage)) die("failed to load verstage"); /* verify and select a slot */ prog_run(&verstage); /* This is not actually possible to hit this condition at * runtime, but this provides a hint to the compiler for dead * code elimination below. */ if (!CONFIG(VBOOT_RETURN_FROM_VERSTAGE)) return; car_set_var(vboot_executed, 1); } /* * Fill in vboot cbmem objects before moving to ramstage so all * downstream users have access to vboot results. This path only * applies to platforms employing VBOOT_STARTS_IN_ROMSTAGE because * cbmem comes online prior to vboot verification taking place. For * other platforms the vboot cbmem objects are initialized when * cbmem comes online. */ if (ENV_ROMSTAGE && CONFIG(VBOOT_STARTS_IN_ROMSTAGE)) vboot_fill_handoff(); } static int vboot_locate(struct cbfs_props *props) { struct region selected_region; /* Don't honor vboot results until the vboot logic has run. */ if (!vboot_logic_executed()) return -1; if (vboot_get_selected_region(&selected_region)) return -1; props->offset = region_offset(&selected_region); props->size = region_sz(&selected_region); return 0; } const struct cbfs_locator vboot_locator = { .name = "VBOOT", .prepare = vboot_prepare, .locate = vboot_locate, };