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// 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.
//
// This file contains structures used to facilitate EC firmware updates
// over USB. Note that many contents in this file are copied from EC overlay,
// and it might be trickier to include them directly.
//
// The firmware update protocol consists of two phases: connection
// establishment and actual image transfer.
//
// Image transfer is done in 1K blocks. The host supplying the image
// encapsulates blocks in PDUs by prepending a header including the flash
// offset where the block is destined and its digest.
//
// The EC device responds to each PDU with a confirmation which is 1 byte
// response. Zero value means success, non zero value is the error code
// reported by EC.
//
// To establish the connection, the host sends a different PDU, which
// contains no data and is destined to offset 0. Receiving such a PDU
// signals the EC that the host intends to transfer a new image.
//
// The connection establishment response is described by the
// FirstResponsePdu structure below.
#ifndef HAMMERD_UPDATE_FW_H_
#define HAMMERD_UPDATE_FW_H_
#include <stdint.h>
#include <memory>
#include <string>
#include <vector>
#include <base/macros.h>
#include <gtest/gtest_prod.h>
#include <openssl/sha.h>
#include "hammerd/fmap_utils.h"
#include "hammerd/usb_utils.h"
namespace hammerd {
constexpr int kUpdateProtocolVersion = 6;
constexpr uint32_t kUpdateDoneCmd = 0xB007AB1E;
constexpr uint32_t kUpdateExtraCmd = 0xB007AB1F;
constexpr int kEntropySize = 32;
enum class FirstResponsePduHeaderType {
kCR50 = 0,
kCommon = 1,
};
// The extra vendor subcommand.
enum class UpdateExtraCommand : uint16_t {
kImmediateReset = 0,
kJumpToRW = 1,
kStayInRO = 2,
kUnlockRW = 3,
kUnlockRollback = 4,
kInjectEntropy = 5,
kPairChallenge = 6,
kTouchpadInfo = 7,
};
const char* ToString(UpdateExtraCommand subcommand);
enum class EcResponseStatus : uint8_t {
kSuccess = 0,
kInvalidCommand = 1,
kError = 2,
kInvalidParam = 3,
kAccessDenied = 4,
kInvalidResponse = 5,
kInvalidVersion = 6,
kInvalidChecksum = 7,
kInProgress = 8, // Accepted, command in progress
kUnavailable = 9, // No response available
kTimeout = 10, // We got a timeout
kOverflow = 11, // Table / data overflow
kInvalidHeader = 12, // Header contains invalid data
kRequestTruncated = 13, // Didn't get the entire request
kResponseTooBig = 14, // Response was too big to handle
kBusError = 15, // Communications bus error
kBusy = 16, // Up but too busy. Should retry
};
// 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, and puts its reply
// into the same buffer the PDU was in.
struct UpdateFrameHeader {
uint32_t block_size; // Total frame size, including this field.
uint32_t block_digest;
uint32_t block_base;
UpdateFrameHeader() : UpdateFrameHeader(0, 0, 0) {}
UpdateFrameHeader(uint32_t size, uint32_t digest, uint32_t base)
: block_size(htobe32(size)),
block_digest(htobe32(digest)),
block_base(htobe32(base)) {}
};
// 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 FirstResponsePdu {
uint32_t return_value;
// The below fields are present in versions 2 and up.
// Type of header following (one of first_response_pdu_header_type)
uint16_t header_type;
uint16_t protocol_version; // Must be kUpdateProtocolVersion
uint32_t maximum_pdu_size; // Maximum PDU size
uint32_t flash_protection; // Flash protection status
uint32_t offset; // Offset of the other region
char version[32]; // Version string of the other region
int32_t min_rollback; // Minimum rollback version that RO will accept
uint32_t key_version; // RO public key version
};
enum class SectionName {
RO,
RW,
Invalid,
};
const char* ToString(SectionName name);
SectionName OtherSection(SectionName name);
// product_id format from elan_i2c.h. definition of ETP_PRODUCT_ID_FORMAT_STRING
constexpr char kElanFormatString[] = "%d.0";
// Below is the touchpad_info struct from src/platform/ec/include/update_fw.h.
struct __attribute__((packed)) TouchpadInfo {
uint8_t status; // Indicate if we get info from touchpad
uint8_t reserved; // Reserved for padding
uint16_t vendor; // Vendor USB id
uint32_t fw_address; // Virtual address to touchpad firmware
uint32_t fw_size; // Size of the touchpad firmware
// Checksum of the entire touchpad firmware accepted by the EC image
uint8_t allowed_fw_hash[SHA256_DIGEST_LENGTH];
struct {
uint16_t id;
uint16_t fw_version;
uint16_t fw_checksum;
} elan;
};
// The section information of the new EC image.
struct SectionInfo {
SectionName name;
uint32_t offset;
uint32_t size;
char version[32];
int32_t rollback;
int32_t key_version;
explicit SectionInfo(SectionName name);
SectionInfo(SectionName name,
uint32_t offset,
uint32_t size,
const char* version,
int32_t rollback,
int32_t key_version);
friend bool operator==(const SectionInfo& lhs, const SectionInfo& rhs);
friend bool operator!=(const SectionInfo& lhs, const SectionInfo& rhs);
};
class FirmwareUpdaterInterface {
public:
virtual ~FirmwareUpdaterInterface() = default;
// Scans the new EC image and retrieve versions of RO and RW sections.
virtual bool LoadEcImage(const std::string& ec_image) = 0;
// Retrieves local touchpad firmware.
virtual bool LoadTouchpadImage(const std::string& touchpad_image) = 0;
// Tries to connect to the USB endpoint during a period of time.
virtual UsbConnectStatus TryConnectUsb() = 0;
// Closes the connection to the USB endpoint.
virtual void CloseUsb() = 0;
// Setups the connection with the EC firmware by sending the first PDU.
// Returns true if successfully setup the connection.
virtual bool SendFirstPdu() = 0;
// Indicates to hammer that transferal of EC/touchpad firmware has completed.
// Upon receipt of this message the target state machine transitions into
// the 'rx_idle' state. The host may send an extension command to reset the
// target after this.
virtual void SendDone() = 0;
// Injects entropy into the hammer device.
virtual bool InjectEntropy() = 0;
// Sends the external command through USB. The format of the payload is:
// 4 bytes 4 bytes 4 bytes 2 bytes variable size
// +-----------+--------------+---------------+-----------+------~~~-------+
// + total size| block digest | EXT_CMD | Vend. sub.| data |
// +-----------+--------------+---------------+-----------+------~~~-------+
//
// Where 'Vend. sub' is the vendor subcommand, and data field is subcommand
// dependent. The target tells between update PDUs and encapsulated vendor
// subcommands by looking at the EXT_CMD value - it is kUpdateExtraCmd and
// as such is guaranteed not to be a valid update PDU destination address.
virtual bool SendSubcommand(UpdateExtraCommand subcommand) = 0;
virtual bool SendSubcommandWithPayload(UpdateExtraCommand subcommand,
const std::string& cmd_body) = 0;
virtual bool SendSubcommandReceiveResponse(UpdateExtraCommand subcommand,
const std::string& cmd_body,
void* resp,
size_t resp_size) = 0;
// Transfers the image to the target section.
virtual bool TransferImage(SectionName section_name) = 0;
// Transfers the touchpad firmware to a virtual address.
virtual bool TransferTouchpadFirmware(uint32_t section_addr,
size_t data_len) = 0;
// Returns the current section that EC is running. One of "RO" or "RW".
virtual SectionName CurrentSection() const = 0;
// Returns whether the key version of the local image is valid
// (i.e. matches key version in RW section of EC).
virtual bool ValidKey() const = 0;
// Returns whether the rollback version of the local image is valid
// (i.e. >= rollback stored in RB section of EC).
virtual bool ValidRollback() const = 0;
// Determines whether the given section has a different firmware version
// from that of the local file.
virtual bool VersionMismatch(SectionName section_name) const = 0;
// Determines the section is locked or not.
virtual bool IsSectionLocked(SectionName section_name) const = 0;
// Unlocks the section. Need to send "Reset" command afterward.
virtual bool UnlockSection(SectionName section_name) = 0;
// Determines the rollback is locked or not.
virtual bool IsRollbackLocked() const = 0;
// Unlocks the rollback. Need to send "Reset" command afterward.
virtual bool UnlockRollback() = 0;
virtual std::string GetEcImageVersion() const = 0;
};
// Implement the core logic of updating firmware.
// It contains the data of the original transfer_descriptor.
class FirmwareUpdater : public FirmwareUpdaterInterface {
public:
explicit FirmwareUpdater(std::unique_ptr<UsbEndpoint> endpoint);
// FirmwareUpdaterInterface implementation:
bool LoadEcImage(const std::string& ec_image) override;
bool LoadTouchpadImage(const std::string& touchpad_image) override;
UsbConnectStatus TryConnectUsb() override;
void CloseUsb() override;
bool SendFirstPdu() override;
void SendDone() override;
bool InjectEntropy() override;
// InjectEntropyWithPayload is exposed at hammerd_api for FAFT use.
// It should not be called directly in hammer_updater.
bool InjectEntropyWithPayload(const std::string& payload);
bool SendSubcommand(UpdateExtraCommand subcommand) override;
bool SendSubcommandWithPayload(UpdateExtraCommand subcommand,
const std::string& cmd_body) override;
bool SendSubcommandReceiveResponse(UpdateExtraCommand subcommand,
const std::string& cmd_body,
void* resp,
size_t resp_size) override;
bool TransferImage(SectionName section_name) override;
bool TransferTouchpadFirmware(uint32_t section_addr,
size_t data_len) override;
SectionName CurrentSection() const override;
bool ValidKey() const override;
bool ValidRollback() const override;
bool VersionMismatch(SectionName section_name) const override;
bool IsSectionLocked(SectionName section_name) const override;
bool UnlockSection(SectionName section_name) override;
bool IsRollbackLocked() const override;
bool UnlockRollback() override;
std::string GetEcImageVersion() const override;
protected:
// Used in unit tests to inject mocks.
FirmwareUpdater(std::unique_ptr<UsbEndpointInterface> endpoint,
std::unique_ptr<FmapInterface> fmap);
// Fetches the version of the currently-running section.
bool FetchVersion();
// Transfers the data of the target section.
bool TransferSection(const uint8_t* data_ptr,
uint32_t section_addr,
size_t data_len, bool use_block_skip);
// Transfers a block of data.
bool TransferBlock(UpdateFrameHeader* ufh,
const uint8_t* transfer_data_ptr,
size_t payload_size, bool use_block_skip);
// The USB endpoint interface to the hammer EC.
std::unique_ptr<UsbEndpointInterface> endpoint_;
// The fmap function interface.
std::unique_ptr<FmapInterface> fmap_;
// The information of the first response PDU.
FirstResponsePdu targ_;
// The version of the currently-running section. Retrieved through USB
// endpoint's configuration string descriptor as part of TryConnectUsb.
std::string version_;
// The EC image data to be updated.
std::string ec_image_;
// The touchpad image data to be updated.
std::string touchpad_image_;
// The information of the RO and RW sections in the EC image data.
std::vector<SectionInfo> sections_;
friend class FirmwareUpdaterTest;
FRIEND_TEST(FirmwareUpdaterTest, LoadEcImage);
FRIEND_TEST(FirmwareUpdaterTest, TryConnectUsb_OK);
FRIEND_TEST(FirmwareUpdaterTest, TryConnectUsb_FAIL);
FRIEND_TEST(FirmwareUpdaterTest, TryConnectUsb_FetchVersion_Legacy);
FRIEND_TEST(FirmwareUpdaterTest, TryConnectUsb_FetchVersion_FAIL);
FRIEND_TEST(FirmwareUpdaterTest, SendFirstPdu);
FRIEND_TEST(FirmwareUpdaterTest, SendDone);
FRIEND_TEST(FirmwareUpdaterTest, SendSubcommand_InjectEntropy);
FRIEND_TEST(FirmwareUpdaterTest, SendSubcommand_Reset);
FRIEND_TEST(FirmwareUpdaterTest, TransferImage);
FRIEND_TEST(FirmwareUpdaterTest, CurrentSection);
FRIEND_TEST(FirmwareUpdaterTest, CheckKeyRollback);
FRIEND_TEST(FirmwareUpdaterTest, VersionMismatch);
private:
bool CheckEmptyBlock(const uint8_t* transfer_data_ptr, size_t payload_size);
DISALLOW_COPY_AND_ASSIGN(FirmwareUpdater);
};
} // namespace hammerd
#endif // HAMMERD_UPDATE_FW_H_