topic i.mx6ull Bootup With Uncompress Kernel in i.MX Processors

i.mx6ull Bootup With Uncompress Kernel

tkcheng01 — Fri, 26 Jan 2018 06:19:21 GMT

I would like to benchmark the performance of booting using uncompress kernel. I am using yocto guide from NXP and currently my kernel version is 4.9.11. By default, the yocto system generated zImage.

In the yocto build system below path, i found the file name 'Image'

yocto/build-fb/tmp/work/imx6ull14x14evk-poky-linux-gnueabi/linux-imx/4.9.11-r0/build/arch/arm/boot

I use uboot-image to convert this file into uImage file with the following command:

uboot-mkimage -A arm -O linux -T kernel -C none -a 80800000 -e 80800000 -n myuImage -d Image uImage

When I boot uImage file, the boot up process stop at 'Starting kernel ...'

My Uboot command as below:

run mmcargs;
run loadfdt;
fatload mmc 1 0x80800000 uImage  (from SD)bootm 0x80800000 - 0x83000000

Console output as below:

17350720 bytes read in 766 ms (21.6 MiB/s)
=> bootm 0x80800000 - 0x83000000
## Booting kernel from Legacy Image at 80800000 ...
   Image Name:   myuImage
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    17350656 Bytes = 16.5 MiB
   Load Address: 80800000
   Entry Point:  80800000
   Verifying Checksum ... OK
## Flattened Device Tree blob at 83000000
   Booting using the fdt blob at 0x83000000
   Loading Kernel Image ... OK
   Using Device Tree in place at 83000000, end 8300be5d
Modify /soc/aips-bus@02200000/epdc@0228c000:status disabled
ft_system_setup for mx6




Starting kernel ...

Re: i.mx6ull Bootup With Uncompress Kernel

igorpadykov — Fri, 26 Jan 2018 11:33:52 GMT

Hi tk

one can look on

linux - Why using a uImage instead of a zImage - Stack Overflow

and post it on kernel mail list as this is general linux question.

Best regards
igor
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Re: i.mx6ull Bootup With Uncompress Kernel

tkcheng01 — Mon, 29 Jan 2018 03:23:00 GMT

Hi Igor,

Thanks for the feedback. Additional reference from this link.

Below command is working well.

$ mkimage -A arm -O linux -T kernel -C none -a 0x80008000 -e 0x80008000 -n 'Linux' -d arch/arm/boot/Image arch/arm/boot/uImage