cros_bundle_firmware: Checksum the payload before and after sending
At present the checksum is displayed for the user but there is no actual
check that it is correct.
Calculate the checksum, send it with the payload and check it in the
flasher script. Then display a failure and refuse to continue when the
data has been corrupted by the download or other code.
BUG=chromium-os:19724
TEST=manual:
cros_bundle_firmware on exynos
- See a checksum failure message on the U-Boot console
Firmware loaded to 0x43e3f000, size 0x3a661, length 0x3b000
CRC32 for 43e3f000 ... 43e79660 ==> 04c9b186 != 5e18c807 ** ERROR **
** Checksum error on load: please check download tool **
Create a file with all zeros (zero.bin)
cros_write_firmware -w usb -i zero.bin -b daisy
-d board/samsung/dts/exynos5250-daisy.dts -I arch/arm/dts -I cros/dts
-U u-boot.bin
- See that it succeeds
Change-Id: Id9384eb2b87753cef7a38f208a6395c3681a3d62
Reviewed-on: https://gerrit.chromium.org/gerrit/18866
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Commit-Ready: Simon Glass <sjg@chromium.org>
diff --git a/host/lib/write_firmware.py b/host/lib/write_firmware.py
index ee09efc..cf2eef3 100644
--- a/host/lib/write_firmware.py
+++ b/host/lib/write_firmware.py
@@ -2,6 +2,7 @@
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
+import binascii
import os
import re
import time
@@ -51,7 +52,8 @@
self.update = True
self.verify = False
- def _GetFlashScript(self, payload_size, update, verify, boot_type, bus=0):
+ def _GetFlashScript(self, payload_size, update, verify, boot_type, checksum,
+ bus='0'):
"""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,
@@ -62,7 +64,9 @@
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
- boot_type: the src for bootdevice (Nand, Sdmmc, or Spi)
+ boot_type: The source for bootdevice (Nand, Sdmmc, or Spi)
+ checksum: The checksum of the payload (an integer)
+ bus: The bus number
Returns:
A tuple containing:
@@ -83,7 +87,8 @@
'setenv firmware_size %#x' % payload_size,
'setenv length %#x' % RoundUp(payload_size, page_size),
'setenv blocks %#x' % (RoundUp(payload_size, page_size) / page_size),
- 'setenv _crc "crc32 ${address} ${firmware_size}"',
+ 'setenv _crc "crc32 -v ${address} ${firmware_size} %#08x"' %
+ checksum,
'setenv _clear "echo Clearing RAM; mw.b ${address} 0 ${length}"',
]
if boot_type == 'Nand':
@@ -114,7 +119,7 @@
cmds.extend([
'echo Firmware loaded to ${address}, size ${firmware_size}, '
'length ${length}',
- 'run _crc',
+ 'if run _crc; then',
'run _init',
])
if update:
@@ -126,10 +131,15 @@
'run _clear',
'run _read',
'run _crc',
- 'echo If the two CRCs above are equal, flash was successful.'
]
else:
cmds += ['echo Skipping verify']
+ cmds.extend([
+ 'else',
+ 'echo',
+ 'echo "** Checksum error on load: please check download tool **"',
+ 'fi',
+ ])
script = '; '.join(cmds)
return script, replace_me
@@ -155,10 +165,14 @@
Filename of the flasher binary created.
"""
fdt = self._fdt.Copy(os.path.join(self._tools.outdir, 'flasher.dtb'))
+ payload_data = self._tools.ReadFile(payload)
payload_size = os.stat(payload).st_size
- script, replace_me = self._GetFlashScript(payload_size, update, verify,
- boot_type, bus)
+ # Make sure that the checksum is not negative
+ checksum = binascii.crc32(payload_data) & 0xffffffff
+
+ script, replace_me = self._GetFlashScript(len(payload_data), update,
+ verify, boot_type, checksum, bus)
data = self._tools.ReadFile(uboot)
fdt.PutString('/config', 'bootcmd', script)
fdt_data = self._tools.ReadFile(fdt.fname)
@@ -178,7 +192,7 @@
# NAND driver expects 4-byte alignment. Just go whole hog and do 4K.
alignment = 0x1000
- payload_offset = (payload_offset + alignment - 1) & ~(alignment-1)
+ payload_offset = (payload_offset + alignment - 1) & ~(alignment - 1)
load_address = self.text_base + payload_offset,
new_str = '%08x' % load_address
@@ -193,13 +207,14 @@
# Now put it together.
data += fdt_data
data += "\0" * (payload_offset - len(data))
- data += self._tools.ReadFile(payload)
+ data += payload_data
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._out.Notice('Payload checksum %08x' % checksum)
self._tools.OutputSize('Flasher', flasher)
return flasher