mirror of https://gitee.com/openkylin/linux.git
89 lines
3.1 KiB
Plaintext
89 lines
3.1 KiB
Plaintext
|
Upgrading BIOS using intel-spi
|
||
|
|
------------------------------
|
||
|
|
|
||
|
|
Many Intel CPUs like Baytrail and Braswell include SPI serial flash host
|
||
|
|
controller which is used to hold BIOS and other platform specific data.
|
||
|
|
Since contents of the SPI serial flash is crucial for machine to function,
|
||
|
|
it is typically protected by different hardware protection mechanisms to
|
||
|
|
avoid accidental (or on purpose) overwrite of the content.
|
||
|
|
|
||
|
|
Not all manufacturers protect the SPI serial flash, mainly because it
|
||
|
|
allows upgrading the BIOS image directly from an OS.
|
||
|
|
|
||
|
|
The intel-spi driver makes it possible to read and write the SPI serial
|
||
|
|
flash, if certain protection bits are not set and locked. If it finds
|
||
|
|
any of them set, the whole MTD device is made read-only to prevent
|
||
|
|
partial overwrites. By default the driver exposes SPI serial flash
|
||
|
|
contents as read-only but it can be changed from kernel command line,
|
||
|
|
passing "intel-spi.writeable=1".
|
||
|
|
|
||
|
|
Please keep in mind that overwriting the BIOS image on SPI serial flash
|
||
|
|
might render the machine unbootable and requires special equipment like
|
||
|
|
Dediprog to revive. You have been warned!
|
||
|
|
|
||
|
|
Below are the steps how to upgrade MinnowBoard MAX BIOS directly from
|
||
|
|
Linux.
|
||
|
|
|
||
|
|
1) Download and extract the latest Minnowboard MAX BIOS SPI image
|
||
|
|
[1]. At the time writing this the latest image is v92.
|
||
|
|
|
||
|
|
2) Install mtd-utils package [2]. We need this in order to erase the SPI
|
||
|
|
serial flash. Distros like Debian and Fedora have this prepackaged with
|
||
|
|
name "mtd-utils".
|
||
|
|
|
||
|
|
3) Add "intel-spi.writeable=1" to the kernel command line and reboot
|
||
|
|
the board (you can also reload the driver passing "writeable=1" as
|
||
|
|
module parameter to modprobe).
|
||
|
|
|
||
|
|
4) Once the board is up and running again, find the right MTD partition
|
||
|
|
(it is named as "BIOS"):
|
||
|
|
|
||
|
|
# cat /proc/mtd
|
||
|
|
dev: size erasesize name
|
||
|
|
mtd0: 00800000 00001000 "BIOS"
|
||
|
|
|
||
|
|
So here it will be /dev/mtd0 but it may vary.
|
||
|
|
|
||
|
|
5) Make backup of the existing image first:
|
||
|
|
|
||
|
|
# dd if=/dev/mtd0ro of=bios.bak
|
||
|
|
16384+0 records in
|
||
|
|
16384+0 records out
|
||
|
|
8388608 bytes (8.4 MB) copied, 10.0269 s, 837 kB/s
|
||
|
|
|
||
|
|
6) Verify the backup
|
||
|
|
|
||
|
|
# sha1sum /dev/mtd0ro bios.bak
|
||
|
|
fdbb011920572ca6c991377c4b418a0502668b73 /dev/mtd0ro
|
||
|
|
fdbb011920572ca6c991377c4b418a0502668b73 bios.bak
|
||
|
|
|
||
|
|
The SHA1 sums must match. Otherwise do not continue any further!
|
||
|
|
|
||
|
|
7) Erase the SPI serial flash. After this step, do not reboot the
|
||
|
|
board! Otherwise it will not start anymore.
|
||
|
|
|
||
|
|
# flash_erase /dev/mtd0 0 0
|
||
|
|
Erasing 4 Kibyte @ 7ff000 -- 100 % complete
|
||
|
|
|
||
|
|
8) Once completed without errors you can write the new BIOS image:
|
||
|
|
|
||
|
|
# dd if=MNW2MAX1.X64.0092.R01.1605221712.bin of=/dev/mtd0
|
||
|
|
|
||
|
|
9) Verify that the new content of the SPI serial flash matches the new
|
||
|
|
BIOS image:
|
||
|
|
|
||
|
|
# sha1sum /dev/mtd0ro MNW2MAX1.X64.0092.R01.1605221712.bin
|
||
|
|
9b4df9e4be2057fceec3a5529ec3d950836c87a2 /dev/mtd0ro
|
||
|
|
9b4df9e4be2057fceec3a5529ec3d950836c87a2 MNW2MAX1.X64.0092.R01.1605221712.bin
|
||
|
|
|
||
|
|
The SHA1 sums should match.
|
||
|
|
|
||
|
|
10) Now you can reboot your board and observe the new BIOS starting up
|
||
|
|
properly.
|
||
|
|
|
||
|
|
References
|
||
|
|
----------
|
||
|
|
|
||
|
|
[1] https://firmware.intel.com/sites/default/files/MinnowBoard.MAX_.X64.92.R01.zip
|
||
|
|
[2] http://www.linux-mtd.infradead.org/
|