mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-08 22:24:32 +00:00
26a6ed1b2e
Convert pcm058 support to use device trees and the driver model. Add rudimentary boot scripts to the environment, expand README. Signed-off-by: Niel Fourie <lusus@denx.de> Cc: Stefano Babic <sbabic@denx.de>
86 lines
3 KiB
Text
86 lines
3 KiB
Text
Board information
|
|
-----------------
|
|
|
|
The SBC produced by Phytec has a SOM based on a i.MX6Q.
|
|
The SOM is sold in two versions, with eMMC or with NAND. Support
|
|
here is for the SOM with NAND.
|
|
The evaluation board "phyBoard-Mira" is thought to be used
|
|
together with the SOM.
|
|
|
|
More information on the board can be found on manufacturer's
|
|
website:
|
|
|
|
http://www.phytec.de/produkt/single-board-computer/phyboard-mira/
|
|
http://www.phytec.de/fileadmin/user_upload/images/content/1.Products/SOMs/phyCORE-i.MX6/L-808e_1.pdf
|
|
|
|
Building U-Boot
|
|
-------------------------------
|
|
|
|
$ make pcm058_defconfig
|
|
$ make
|
|
|
|
This generates the artifacts SPL and u-boot.img.
|
|
The SOM can boot from NAND or from SD-Card, having the SPI-NOR
|
|
as second option.
|
|
The dip switch "DIP-1" on the board let choose between
|
|
NAND and SD.
|
|
|
|
DIP-1 set to off: Boot first from NAND, then try SPI
|
|
DIP-1 set to on: Boot first from SD, then try SPI
|
|
|
|
The bootloader was tested with DIP-1 set to on. If a SD-card
|
|
is present, then the RBL tries to load SPL from the SD Card, if not,
|
|
RBL loads from SPI-NOR. The SPL tries then to load from the same
|
|
device where SPL was loaded (SD or SPI). Booting from NAND is
|
|
not supported.
|
|
|
|
Flashing U-Boot onto an SD card
|
|
-------------------------------
|
|
|
|
After a successful build, the generated SPL and U-boot binaries can be copied
|
|
to an SD card. Adjust the SD card device as necessary:
|
|
|
|
$ sudo dd if=u-boot-with-spl.imx of=/dev/mmcblk0 bs=1k seek=1
|
|
|
|
This is equivalent to separately copying the SPL and U-boot using:
|
|
|
|
$ sudo dd if=SPL of=/dev/mmcblk0 bs=1k seek=1
|
|
$ sudo dd if=u-boot-dtb.img of=/dev/mmcblk0 bs=1k seek=197
|
|
|
|
The default bootscripts expect a kernel fit-image file named "fitImage" in the
|
|
first partition and Linux ext4 rootfs in the second partition.
|
|
|
|
Flashing U-boot to the SPI Flash, for booting Linux from NAND
|
|
-------------------------------------------------------------
|
|
|
|
The SD card created above can also be used to install the SPL and U-boot into
|
|
the SPI flash. Boot U-boot from the SD card as above, and stop at the autoboot.
|
|
|
|
Then, clear the SPI flash:
|
|
|
|
=> sf probe
|
|
=> sf erase 0x0 0x1000000
|
|
|
|
Load the SPL from raw MMC into memory and copy to the SPI. The SPL is maximum
|
|
392*512-byte blocks in size therefore 0x188 blocks, totaling 0x31000 bytes:
|
|
|
|
=> mmc read ${loadaddr} 0x2 0x188
|
|
=> sf write ${loadaddr} 0x400 0x31000
|
|
|
|
Load the U-boot binary into memory and copy to the SPI. U-boot should fit into
|
|
640KiB, so 0x500 512-byte blocks, totalling 0xA0000 bytes:
|
|
|
|
=> mmc read ${loadaddr} 0x18a 0x500
|
|
=> sf write ${loadaddr} 0x40000 0xA0000
|
|
|
|
The default NAND bootscripts expect a single MTD partition named "rootfs",
|
|
which in turn contains the UBI volumes "fit" (which contains the kernel fit-
|
|
image) and "root" (which contains a ubifs root filesystem).
|
|
|
|
The "bootm_size" variable in the environment
|
|
--------------------------------------------
|
|
|
|
By default, U-boot relocates the device tree towards the upper end of the RAM,
|
|
which kernels using CONFIG_HIGHMEM=y may not be able to access during early
|
|
boot. With the bootm_size variable set to 0x30000000, U-boot relocates the
|
|
device tree to below this address instead.
|