Colibri iMX7¶
Quick Start¶
- Build U-Boot
- NAND IMX image adjustments before flashing
- Flashing manually U-Boot to eMMC
- Flashing manually U-Boot to NAND
- Using
update_uboot
script
Build U-Boot¶
$ export CROSS_COMPILE=arm-linux-gnueabi-
$ export ARCH=arm
$ make colibri_imx7_emmc_defconfig # For NAND: colibri_imx7_defconfig
$ make
After build succeeds, you will obtain final u-boot-dtb.imx
IMX specific
image, ready for flashing (but check next section for additional
adjustments).
Final IMX program image includes (section 6.6.7
from IMX7DRM):
- Image vector table (IVT) for BootROM
- Boot data -indicates the program image location, program image size in bytes, and the plugin flag.
- Device configuration data
- User image: U-Boot image (
u-boot-dtb.bin
)
IMX image adjustments prior to flashing¶
1. U-Boot for both Colibri iMX7 NAND and eMMC versions
is built with HABv4 support (AN4581.pdf)
enabled by default, which requires to generate a proper
Command Sequence File (CSF) by srktool from NXP (not included in the
U-Boot tree, check additional details in introduction_habv4.txt)
and concatenate it to the final u-boot-dtb.imx
.
2. In case if you don’t want to generate a proper CSF
(for any reason),
you still need to pad the IMX image so i has the same size as specified in
in Boot Data section of IMX image.
To obtain this value, run:
$ od -X -N 0x30 u-boot-dtb.imx
0000000 402000d1 87800000 00000000 877ff42c
0000020 877ff420 877ff400 878a5000 00000000
^^^^^^^^
0000040 877ff000 000a8060 00000000 40b401d2
^^^^^^^^ ^^^^^^^^
Where:
877ff400
- IVT self address877ff000
- Program image address000a8060
- Program image size
To calculate the padding:
- IVT offset =
0x877ff400
-0x877ff000
=0x400
- Program image size =
0xa8060
-0x400
=0xa7c60
and then pad the image:
$ objcopy -I binary -O binary --pad-to 0xa7c60 --gap-fill=0x00 \
u-boot-dtb.imx u-boot-dtb.imx.zero-padded
3. Also, according to requirement from 6.6.7.1
, the final image
should have 0x400
offset for initial IVT table.
For eMMC setup we handle this by flashing it to 0x400
, howewer
for NAND setup we adjust the image prior to flashing, adding padding in the
beginning of the image.
$ dd if=u-boot-dtb.imx.zero-padded of=u-boot-dtb.imx.ready bs=1024 seek=1
Flash U-Boot IMX image to eMMC¶
Flash the u-boot-dtb.imx.zero-padded
binary to the primary eMMC hardware
boot area partition:
=> load mmc 1:1 $loadaddr u-boot-dtb.imx.zero-padded
=> setexpr blkcnt ${filesize} + 0x1ff && setexpr blkcnt ${blkcnt} / 0x200
=> mmc dev 0 1
=> mmc write ${loadaddr} 0x2 ${blkcnt}
Flash U-Boot IMX image to NAND¶
=> load mmc 1:1 $loadaddr u-boot-dtb.imx.ready
=> nand erase.part u-boot1
=> nand write ${loadaddr} u-boot1 ${filesize}
=> nand erase.part u-boot2
=> nand write ${loadaddr} u-boot2 ${filesize}
Using update_uboot script¶
You can also usb U-Boot env update_uboot script, which wraps all eMMC/NAND specific command invocation:
=> load mmc 1:1 $loadaddr u-boot-dtb.imx.ready
=> run update_uboot