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/* Copyright 2016 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.
*/
#include "byteorder.h"
#include "common.h"
#include "console.h"
#include "consumer.h"
#include "queue_policies.h"
#include "shared_mem.h"
#include "system.h"
#include "upgrade_fw.h"
#include "usb-stream.h"
#define CPRINTS(format, args...) cprints(CC_USB, format, ## args)
/*
* This file is an adaptation layer between the USB interface and the firmware
* update engine. The engine expects to receive long blocks of data, 1K or so
* in size, prepended by the offset where the data needs to be programmed into
* the flash and a 4 byte integrity check value.
*
* The USB transfer, on the other hand, operates on much shorter chunks of
* data, typically 64 bytes in this case. This module reassembles firmware
* programming blocks from the USB chunks, and invokes the programmer passing
* it the full block.
*
* The programmer reports results by putting the return value of one or four
* bytes into the same buffer where the block was passed in. This wrapper
* retrieves the programmer's return value, normalizes it to 4 bytes and sends
* it back to the host.
*
* In the end of the successful image transfer and programming, the host send
* the reset command, and the device reboots itself.
*/
struct consumer const upgrade_consumer;
struct usb_stream_config const usb_upgrade;
static struct queue const upgrade_to_usb = QUEUE_DIRECT(64, uint8_t,
null_producer,
usb_upgrade.consumer);
static struct queue const usb_to_upgrade = QUEUE_DIRECT(64, uint8_t,
usb_upgrade.producer,
upgrade_consumer);
USB_STREAM_CONFIG_FULL(usb_upgrade,
USB_IFACE_UPGRADE,
USB_CLASS_VENDOR_SPEC,
USB_SUBCLASS_GOOGLE_CR50,
USB_PROTOCOL_GOOGLE_CR50_NON_HC_FW_UPDATE,
USB_STR_UPGRADE_NAME,
USB_EP_UPGRADE,
USB_MAX_PACKET_SIZE,
USB_MAX_PACKET_SIZE,
usb_to_upgrade,
upgrade_to_usb)
/* The receiver can be in one of the states below. */
enum rx_state {
rx_idle, /* Nothing happened yet. */
rx_inside_block, /* Assembling a block to pass to the programmer. */
rx_outside_block, /* Waiting for the next block to start or for the
reset command. */
rx_awaiting_reset /* Waiting for reset confirmation. */
};
/* This is the format of the header the programmer expects. */
struct upgrade_command {
uint32_t block_digest; /* first 4 bytes of sha1 of the rest of the
block. */
uint32_t block_base; /* Offset of this block into the flash SPI. */
};
/* This is the format of the header the host uses. */
struct update_pdu_header {
uint32_t block_size; /* Total size of the block, including this
field. */
union {
struct upgrade_command cmd;
uint32_t resp; /* The programmer puts response to the same
buffer where the command was. */
};
/* The actual payload goes here. */
};
enum rx_state rx_state_ = rx_idle;
static uint8_t *block_buffer;
static uint32_t block_size;
static uint32_t block_index;
/* Called to deal with data from the host */
static void upgrade_out_handler(struct consumer const *consumer, size_t count)
{
struct update_pdu_header updu;
size_t resp_size;
uint32_t resp_value;
if (rx_state_ == rx_idle) {
/* This better be the first block, of zero size. */
if (count != sizeof(struct update_pdu_header)) {
CPRINTS("FW update: wrong first block size %d\n",
count);
return;
}
QUEUE_REMOVE_UNITS(consumer->queue, &updu, count);
CPRINTS("FW update: starting...\n");
fw_upgrade_command_handler(&updu.cmd, count -
offsetof(struct update_pdu_header,
cmd),
&resp_size);
if (resp_size == 4) {
resp_value = updu.resp; /* Already in network order. */
rx_state_ = rx_outside_block;
} else {
/* This must be a single byte error code. */
resp_value = htobe32(*((uint8_t *)&updu.resp));
}
/* Let the host know what upgrader had to say. */
QUEUE_ADD_UNITS(&upgrade_to_usb, &resp_value,
sizeof(resp_value));
return;
}
if (rx_state_ == rx_awaiting_reset) {
/*
* Any USB data received in this state triggers reset, no
* response required.
*/
CPRINTS("reboot hard");
cflush();
system_reset(SYSTEM_RESET_HARD);
while (1)
;
}
if (rx_state_ == rx_outside_block) {
/*
* Expecting to receive the beginning of the block or the
* reset command if all data blocks have been processed.
*/
if (count == 4) {
uint32_t command;
QUEUE_REMOVE_UNITS(consumer->queue, &command,
sizeof(command));
command = be32toh(command);
if (command == UPGRADE_DONE) {
CPRINTS("FW update: done\n");
resp_value = 0;
QUEUE_ADD_UNITS(&upgrade_to_usb, &resp_value,
sizeof(resp_value));
rx_state_ = rx_awaiting_reset;
return;
}
}
if (count < sizeof(updu)) {
CPRINTS("FW update: error: first chunk of %d bytes\n",
count);
rx_state_ = rx_idle;
return;
}
QUEUE_REMOVE_UNITS(consumer->queue, &updu, sizeof(updu));
/* Let's allocate a large enough buffer. */
block_size = be32toh(updu.block_size) -
offsetof(struct update_pdu_header, cmd);
if (shared_mem_acquire(block_size, (char **)&block_buffer)
!= EC_SUCCESS) {
/* TODO:(vbendeb) report out of memory here. */
CPRINTS("FW update: error: failed to alloc %d bytes.\n",
block_size);
return;
}
/*
* Copy the rest of the message into the block buffer to pass
* to the upgrader.
*/
block_index = sizeof(updu) -
offsetof(struct update_pdu_header, cmd);
memcpy(block_buffer, &updu.cmd, block_index);
QUEUE_REMOVE_UNITS(consumer->queue,
block_buffer + block_index,
count - sizeof(updu));
block_index += count - sizeof(updu);
block_size -= block_index;
rx_state_ = rx_inside_block;
return;
}
/* Must be inside block. */
QUEUE_REMOVE_UNITS(consumer->queue, block_buffer + block_index, count);
block_index += count;
block_size -= count;
if (block_size)
return; /* More to come. */
/*
* Ok, the enter block has been received and reassembled, pass it to
* the updater for verification and programming.
*/
fw_upgrade_command_handler(block_buffer, block_index, &resp_size);
shared_mem_release(block_buffer);
resp_value = block_buffer[0];
QUEUE_ADD_UNITS(&upgrade_to_usb, &resp_value, sizeof(resp_value));
rx_state_ = rx_outside_block;
}
static void upgrade_flush(struct consumer const *consumer)
{
}
struct consumer const upgrade_consumer = {
.queue = &usb_to_upgrade,
.ops = &((struct consumer_ops const) {
.written = upgrade_out_handler,
.flush = upgrade_flush,
}),
};
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