diff options
Diffstat (limited to 'common/vboot/vboot.c')
| -rw-r--r-- | common/vboot/vboot.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/common/vboot/vboot.c b/common/vboot/vboot.c new file mode 100644 index 0000000000..27c57b27c2 --- /dev/null +++ b/common/vboot/vboot.c @@ -0,0 +1,199 @@ +/* Copyright 2017 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. + */ + +/* + * Verify and jump to a RW image if power supply is not sufficient. + */ + +#include "battery.h" +#include "charge_manager.h" +#include "chipset.h" +#include "console.h" +#include "host_command.h" +#include "rsa.h" +#include "rwsig.h" +#include "sha256.h" +#include "shared_mem.h" +#include "system.h" +#include "usb_pd.h" +#include "vboot.h" +#include "vb21_struct.h" + +#define CPRINTS(format, args...) cprints(CC_VBOOT, format, ## args) +#define CPRINTF(format, args...) cprintf(CC_VBOOT, format, ## args) + +enum vboot_ec_slot { + VBOOT_EC_SLOT_A, + VBOOT_EC_SLOT_B, +}; + +static int has_matrix_keyboard(void) +{ + return 0; +} + +static int is_vboot_ec_supported(void) +{ +#ifdef CONFIG_VBOOT_EC + return 1; +#else + return 0; +#endif +} + +static int is_low_power_ap_boot_supported(void) +{ + return 0; +} + +static int verify_slot(int slot) +{ + const struct vb21_packed_key *vb21_key; + const struct vb21_signature *vb21_sig; + const struct rsa_public_key *key; + const uint8_t *sig; + const uint8_t *data; + int len; + + CPRINTS("Verifying RW_%c", slot == VBOOT_EC_SLOT_A ? 'A' : 'B'); + + vb21_key = (const struct vb21_packed_key *)( + CONFIG_MAPPED_STORAGE_BASE + + CONFIG_EC_PROTECTED_STORAGE_OFF + + CONFIG_RO_PUBKEY_STORAGE_OFF); + if (vb21_is_packed_key_valid(vb21_key)) { + CPRINTS("Invalid key"); + return EC_ERROR_INVAL; + } + key = (const struct rsa_public_key *) + ((const uint8_t *)vb21_key + vb21_key->key_offset); + + if (slot == VBOOT_EC_SLOT_A) { + data = (const uint8_t *)(CONFIG_MAPPED_STORAGE_BASE + + CONFIG_EC_WRITABLE_STORAGE_OFF + + CONFIG_RW_A_STORAGE_OFF); + vb21_sig = (const struct vb21_signature *)( + CONFIG_MAPPED_STORAGE_BASE + + CONFIG_EC_WRITABLE_STORAGE_OFF + + CONFIG_RW_A_SIGN_STORAGE_OFF); + } else { + data = (const uint8_t *)(CONFIG_MAPPED_STORAGE_BASE + + CONFIG_EC_WRITABLE_STORAGE_OFF + + CONFIG_RW_B_STORAGE_OFF); + vb21_sig = (const struct vb21_signature *)( + CONFIG_MAPPED_STORAGE_BASE + + CONFIG_EC_WRITABLE_STORAGE_OFF + + CONFIG_RW_B_SIGN_STORAGE_OFF); + } + + if (vb21_is_signature_valid(vb21_sig, vb21_key)) { + CPRINTS("Invalid signature"); + return EC_ERROR_INVAL; + } + sig = (const uint8_t *)vb21_sig + vb21_sig->sig_offset; + len = vb21_sig->data_size; + + if (vboot_is_padding_valid(data, len, + CONFIG_RW_SIZE - CONFIG_RW_SIG_SIZE)) { + CPRINTS("Invalid padding"); + return EC_ERROR_INVAL; + } + + if (vboot_verify(data, len, key, sig)) { + CPRINTS("Invalid data"); + return EC_ERROR_INVAL; + } + + return EC_SUCCESS; +} + +static int verify_and_jump(void) +{ + uint8_t slot; + int rv; + + /* 1. Decide which slot to try */ + if (system_get_bbram(SYSTEM_BBRAM_IDX_TRY_SLOT, &slot)) { + CPRINTS("Failed to read try slot"); + slot = VBOOT_EC_SLOT_A; + } + + /* 2. Verify the slot */ + rv = verify_slot(slot); + if (rv) { + if (rv != EC_ERROR_INVAL) + /* Unknown error. The other slot isn't worth trying. */ + return rv; + /* Verification error. The other slot is worth trying. */ + slot = 1 - slot; + if (verify_slot(slot)) + /* Both slots failed */ + return rv; + /* Proceed with the other slot. AP will help us fix it. */ + } + + /* 3. Jump (and reboot) */ + system_run_image_copy(slot == VBOOT_EC_SLOT_A ? + SYSTEM_IMAGE_RW : SYSTEM_IMAGE_RW_B); + + return EC_ERROR_UNKNOWN; +} + +/* Request more power: charging battery or more powerful AC adapter */ +static void request_power(void) +{ + /* TODO: Blink LED */ +} + +static void request_recovery(void) +{ + /* TODO: Blink LED */ +} + +static int is_manual_recovery(void) +{ + return host_get_events() & EC_HOST_EVENT_KEYBOARD_RECOVERY; +} + +void vboot_main(void) +{ + int port = charge_manager_get_active_charge_port(); + + if (port >= CONFIG_USB_PD_PORT_COUNT) { + /* AC is not type-c. No chance to boot. */ + request_power(); + return; + } + + if (pd_comm_is_enabled(port)) + /* Normal RW boot or unlocked RO boot. + * Hoping enough power will be supplied after PD negotiation. */ + return; + + /* PD communication is disabled. Probably this is RO image */ + CPRINTS("PD comm disabled"); + + if (is_manual_recovery()) { + if (battery_is_present() || has_matrix_keyboard()) { + request_power(); + return; + } + CPRINTS("Enable C%d PD communication", port); + pd_comm_enable(port, 1); + /* TODO: Inform PD task and make it negotiate */ + return; + } + + if (!is_vboot_ec_supported() && !is_low_power_ap_boot_supported()) { + request_power(); + return; + } + + /* If successful, this won't return. */ + verify_and_jump(); + + /* Failed to jump. Need recovery. */ + request_recovery(); +} |