blob: dd37d5aa3adae051d8e0d0734ea73390b52427bf [file] [log] [blame]
# Copyright (c) 2011 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.
import os
import re
import time
import tools
from tools import CmdError
def RoundUp(value, boundary):
"""Align a value to the next power of 2 boundary.
value: The value to align.
boundary: The boundary value, e.g. 4096. Must be a power of 2.
The rounded-up value.
return (value + boundary - 1) & ~(boundary - 1)
class WriteFirmware:
"""Write firmware to a Tegra 2 board using USB A-A cable.
This class handles re-reflashing a board with new firmware using the Tegra's
built-in boot ROM feature. This works by putting the chip into a special mode
where it ignores any available firmware and instead reads it from a connected
host machine over USB.
In our case we use that feature to send U-Boot along with a suitable payload
and instructions to flash it to SPI flash. The payload is itself normally a
full Chrome OS image consisting of U-Boot, some keys and verification
information, images and a map of the flash memory.
def __init__(self, tools, fdt, output):
"""Set up a new WriteFirmware object.
tools: A tools library for us to use.
fdt: An fdt which gives us some info that we need.
output: An output object to use for printing progress and messages.
self._tools = tools
self._fdt = fdt
self._out = output
self._text_base = self._fdt.GetInt('/chromeos-config/textbase');
# For speed, use the 'update' algorithm and don't verify
self.update = True
self.verify = False
def _GetFlashScript(self, payload_size, update, verify, is_nand):
"""Get the U-Boot boot command needed to flash U-Boot.
We leave a marker in the string for the load address of the image,
since this depends on the size of this script. This can be replaced by
the caller provided that the marker length is unchanged.
payload_size: Size of payload in bytes.
update: Use faster update algorithm rather then full device erase
verify: Verify the write by doing a readback and CRC
is_nand: True if we're using NAND (instead of SPI Flash)
A tuple containing:
The script, as a string ready to use as a U-Boot boot command, with an
embedded marker for the load address.
The marker string, which the caller should replace with the correct
load address as 8 hex digits, without changing its length.
replace_me = 'zsHEXYla'
cmds = [
'setenv address 0x%s' % replace_me,
'setenv firmware_size %#x' % payload_size,
'setenv length %#x' % RoundUp(payload_size, 4096),
'setenv _crc "crc32 ${address} ${firmware_size}"',
'setenv _clear "echo Clearing RAM; mw.b ${address} 0 ${length}"',
if is_nand:
'setenv _init "echo Init NAND; nand info"',
'setenv _erase "echo Erase NAND; nand erase 0 ${length}"',
'setenv _write "echo Write NAND; nand write ${address} 0 ${length}"',
'setenv _read "echo Read NAND; nand read ${address} 0 ${length}"',
# Don't support update for NAND yet. NAND is fast anyway...
update = False
'setenv _init "echo Init SPI; sf probe 0"',
'setenv _erase "echo Erase SPI; sf erase 0 ${length}"',
'setenv _write "echo Write SPI; sf write ${address} 0 ${length}"',
'setenv _read "echo Read SPI; sf read ${address} 0 ${length}"',
'setenv _update "echo Update SPI; sf update ${address} 0 ${length}"',
'echo Firmware loaded to ${address}, size ${firmware_size}, '
'length ${length}',
'run _crc',
'run _init',
if update:
cmds += ['time run _update']
cmds += ['run _erase', 'run _write']
if verify:
cmds += [
'run _clear',
'run _read',
'run _crc',
'echo If the two CRCs above are equal, flash was successful.'
cmds += ['echo Skipping verify']
script = '; '.join(cmds)
return script, replace_me
def PrepareFlasher(self, uboot, payload, update, verify, is_nand):
"""Get a flasher ready for sending to the board.
The flasher is an executable image consisting of:
- U-Boot (u-boot.bin);
- a special FDT to tell it what to do in the form of a run command;
- (we could add some empty space here, in case U-Boot is not built to
be relocatable);
- the payload (which is a full flash image, or signed U-Boot + fdt).
uboot: Full path to u-boot.bin.
payload: Full path to payload.
update: Use faster update algorithm rather then full device erase
verify: Verify the write by doing a readback and CRC
is_nand: True if we're using NAND (instead of SPI Flash)
Filename of the flasher binary created.
fdt = self._fdt.Copy(os.path.join(self._tools.outdir, 'flasher.dtb'))
payload_size = os.stat(payload).st_size
script, replace_me = self._GetFlashScript(payload_size, update, verify,
data = self._tools.ReadFile(uboot)
fdt.PutString('/config/bootcmd', script)
fdt_data = self._tools.ReadFile(fdt.fname)
# Work out where to place the payload in memory. This is a chicken-and-egg
# problem (although in case you haven't heard, it was the chicken that
# came first), so we resolve it by replacing the string after
# fdt.PutString has done its job.
# Correction: Technically, the egg came first. Whatever genetic mutation
# created the new species would have been present in the egg, but not the
# parent (since if it was in the parent, it would have been present in the
# parent when it was an egg).
# Question: ok so who laid the egg then?
payload_offset = len(data) + len(fdt_data)
# NAND driver expects 4-byte alignment. Just go whole hog and do 4K.
alignment = 0x1000
payload_offset = (payload_offset + alignment - 1) & ~(alignment-1)
load_address = self._text_base + payload_offset,
new_str = '%08x' % load_address
if len(replace_me) is not len(new_str):
raise ValueError("Internal error: replacement string '%s' length does "
"not match new string '%s'" % (replace_me, new_str))
if len(re.findall(replace_me, fdt_data)) != 1:
raise ValueError("Internal error: replacement string '%s' already "
"exists in the fdt (%d matches)" % (replace_me, matches))
fdt_data = re.sub(replace_me, new_str, fdt_data)
# Now put it together.
data += fdt_data
data += "\0" * (payload_offset - len(data))
data += self._tools.ReadFile(payload)
flasher = os.path.join(self._tools.outdir, 'flasher-for-image.bin')
self._tools.WriteFile(flasher, data)
# Tell the user about a few things.
self._tools.OutputSize('U-Boot', uboot)
self._tools.OutputSize('Payload', payload)
self._tools.OutputSize('Flasher', flasher)
return flasher
def FlashImage(self, uboot, bct, payload):
"""Flash the image to SPI flash.
This creates a special Flasher binary, with the image to be flashed as
a payload. This is then sent to the board using the nvflash utility.
uboot: Full path to u-boot.bin.
bct: Full path to BCT file (binary chip timings file for Nvidia SOCs).
payload: Full path to payload.
True if ok, False if failed.
is_nand = "NvBootDevType_Nand" in self._tools.Run('bct_dump', [bct])
flasher = self.PrepareFlasher(uboot, payload, self.update, self.verify,
self._out.Progress('Uploading flasher image')
args = [
'--bct', bct,
'--bl', flasher,
'--setentry', "%#x" % self._text_base, "%#x" % self._text_base
# TODO(sjg): Check for existence of board - but chroot has no lsusb!
last_err = None
for tries in range(10):
# TODO(sjg): Make sudo an argument to Run()
# TODO(sjg): Use Chromite library so we can monitor output
self._tools.Run('sudo', args)
self._out.Notice('Flasher downloaded - please see serial output '
'for progress.')
return True
except CmdError as err:
if not self._out.stdout_is_tty:
return False
# Only show the error output once unless it changes.
err = str(err)
if not 'USB device not found' in err:
raise CmdError('nvflash failed: %s' % err)
if err != last_err:
last_err = err
self._out.Progress('Please connect USB A-A cable and do a '
'recovery-reset', True)
return False
def DoWriteFirmware(output, tools, fdt, flasher, bct_fname, image_fname,
update=True, verify=False):
"""A simple function to write firmware to the board.
This creates a WriteFirmware object and uses it to write the firmware image
to the board.
output: cros_output object to use.
tools: Tools object to use.
fdt: Fdt object to use as our device tree.
flasher: U-Boot binary to use as the flasher.
bct_fname: Bct file to use for the flasher.
image_fname: Filename of image to write.
update: Use faster update algorithm rather then full device erase
verify: Verify the write by doing a readback and CRC
write = WriteFirmware(tools, fdt, output)
write.update = update
write.verify = verify
if write.FlashImage(flasher, bct_fname, image_fname):
output.Progress('Image uploaded - please wait for flashing to '
raise CmdError('Image upload failed - please check board connection')