fwupd/plugins/cros-ec/fu-cros-ec-common.h
2021-08-24 11:18:40 -05:00

143 lines
4.1 KiB
C

/*
* Copyright (C) 2020 Benson Leung <bleung@chromium.org>
*
* SPDX-License-Identifier: LGPL-2.1+
*/
#pragma once
#include <fwupdplugin.h>
#include <glib.h>
#define UPDATE_PROTOCOL_VERSION 6
#define FU_CROS_EC_STRLEN 32
/*
* This is the format of the update PDU header.
*
* block digest: the first four bytes of the sha1 digest of the rest of the
* structure (can be 0 on boards where digest is ignored).
* block_base: offset of this PDU into the flash SPI.
*/
typedef struct __attribute__((packed)) {
guint32 block_digest;
guint32 block_base;
/* The actual payload goes here. */
} update_command;
/*
* This is the frame format the host uses when sending update PDUs over USB.
*
* The PDUs are up to 1K bytes in size, they are fragmented into USB chunks of
* 64 bytes each and reassembled on the receive side before being passed to
* the flash update function.
*
* The flash update function receives the unframed PDU body (starting at the
* cmd field below), and puts its reply into the same buffer the PDU was in.
*/
struct update_frame_header {
guint32 block_size; /* Total frame size, including this field. */
update_command cmd;
};
/*
* A convenience structure which allows to group together various revision
* fields of the header created by the signer (cr50-specific).
*
* These fields are compared when deciding if versions of two images are the
* same or when deciding which one of the available images to run.
*/
struct signed_header_version {
guint32 minor;
guint32 major;
guint32 epoch;
};
/*
* Response to the connection establishment request.
*
* When responding to the very first packet of the update sequence, the
* original USB update implementation was responding with a four byte value,
* just as to any other block of the transfer sequence.
*
* It became clear that there is a need to be able to enhance the update
* protocol, while staying backwards compatible.
*
* All newer protocol versions (starting with version 2) respond to the very
* first packet with an 8 byte or larger response, where the first 4 bytes are
* a version specific data, and the second 4 bytes - the protocol version
* number.
*
* This way the host receiving of a four byte value in response to the first
* packet is considered an indication of the target running the 'legacy'
* protocol, version 1. Receiving of an 8 byte or longer response would
* communicates the protocol version in the second 4 bytes.
*/
struct first_response_pdu {
guint32 return_value;
/* The below fields are present in versions 2 and up. */
/* Type of header following (one of first_response_pdu_header_type) */
guint16 header_type;
/* Must be UPDATE_PROTOCOL_VERSION */
guint16 protocol_version;
/* In version 6 and up, a board-specific header follows. */
union {
/* cr50 (header_type = UPDATE_HEADER_TYPE_CR50) */
struct {
/* The below fields are present in versions 3 and up. */
guint32 backup_ro_offset;
guint32 backup_rw_offset;
/* The below fields are present in versions 4 and up. */
/*
* Versions of the currently active RO and RW sections.
*/
struct signed_header_version shv[2];
/* The below fields are present in versions 5 and up */
/* keyids of the currently active RO and RW sections. */
guint32 keyid[2];
} cr50;
/* Common code (header_type = UPDATE_HEADER_TYPE_COMMON) */
struct {
/* Maximum PDU size */
guint32 maximum_pdu_size;
/* Flash protection status */
guint32 flash_protection;
/* Offset of the other region */
guint32 offset;
/* Version string of the other region */
gchar version[FU_CROS_EC_STRLEN];
/* Minimum rollback version that RO will accept */
gint32 min_rollback;
/* RO public key version */
guint32 key_version;
} common;
};
};
enum first_response_pdu_header_type {
UPDATE_HEADER_TYPE_CR50 = 0, /* Must be 0 for backwards compatibility */
UPDATE_HEADER_TYPE_COMMON = 1,
};
struct cros_ec_version {
gchar boardname[FU_CROS_EC_STRLEN];
gchar triplet[FU_CROS_EC_STRLEN];
gchar sha1[FU_CROS_EC_STRLEN];
gboolean dirty;
};
gboolean
fu_cros_ec_parse_version(const gchar *version_raw, struct cros_ec_version *version, GError **error);