i.MX ProcessorsのトピックRe: flash u-boot from uboot using ums

flash u-boot from uboot using ums

razriel — Thu, 21 Jul 2022 17:26:40 GMT

I have imx8mn evk board.

I want to be able to test changes in u-boot. I prefer to flash u-boot only to save cycle time instead of flashing the full image.

I am using the ums from the bootloader and able to see boot and rootfs partitions of the emmc on my host/build machine by running ums 0 mmc 2

the u-boot image is not located in the boot partition. I believe its in a known address in the emmc.

I guess I should be able to do a dd command with if=my new u-boot image, of =/dev/mmc and a known offset. can someone confirm its possible. and give me the offsest address and block size.

BR,

Roy

Re: flash u-boot from uboot using ums

dvlogic — Thu, 21 Jul 2022 22:06:56 GMT

I've done that when I was developing my custom u-boot. The dd command is as follows:

dd if=imx-boot of=/dev/imxdisk bs=1k seek=32 conv=fsync

where my /dev/imxdisk is the mounted USB drive exposed by the ums mmc 2 command (Auto-mounted using the following udev rule)

KERNEL=="sd[b-z]", SUBSYSTEM=="block", ATTRS{idVendor}=="0525", ATTRS{idProduct}=="a4a5", ACTION=="add", \
MODE="0666", SYMLINK+="imxdisk"

Re: flash u-boot from uboot using ums

joanxie — Fri, 22 Jul 2022 00:55:44 GMT

you can refer to the linux user guide, which includes detailed information about this

Re: flash u-boot from uboot using ums

razriel — Fri, 22 Jul 2022 08:12:39 GMT

Can you please add page or chapter in the guide ? I was checking it and could not find.

Re: flash u-boot from uboot using ums

joanxie — Sat, 23 Jul 2022 11:16:14 GMT

I mean download images to the board by uuu or dd command, you can refer to the user guide, for ums, you can refer to the link as below:

"https://developer.technexion.com/docs/using-u-boots-ums-command-to-write-flash-storage-over-usb-otg"

Re: flash u-boot from uboot using ums

razriel — Mon, 25 Jul 2022 15:38:23 GMT

I am still unable to see changes I have created in u-boot running

I am doing the followng procedure:

1. creating patch file to be called by bbappend file of my custom u-boot in yocto.

2. the patch file print another printf line in SPL part of "DDRINFO: ddr init"

3. running bitbake imx-image-core

4. verifying source code of u-boot is changed in build/tmp/work/.../git/drivers/ddr_init.c

5. running ums 0 emmc 2 in u-boot terminal

6. running sudo dd if=imx-boot of=/dev/sda bs=1k seek=32 conv=fsync in my ununtu build machine

getting message write is succefull ~1.8 MB in ~0.3 seconds

7. Ctrl C to stop ums in u-boot consloe and running reset command.

8. u-boot loads again with no print new print

what am I doing wrong ?

Thanks,

Roy

Re: flash u-boot from uboot using ums

dvlogic — Mon, 25 Jul 2022 16:41:37 GMT

You probably need to change the boot configuration to boot from main eMMC instead of the special boot part. I'm not in front of my board but I think its the following command

mmc partconf 2 0 0 0

(I think without the parameters the mmc partconf may show you the current settings too)

Re: flash u-boot from uboot using ums

razriel — Mon, 25 Jul 2022 18:50:19 GMT

this is what I get

u-boot=> mmc partconf 2
EXT_CSD[179], PARTITION_CONFIG:
BOOT_ACK: 0x0
BOOT_PARTITION_ENABLE: 0x1
PARTITION_ACCESS: 0x0

can you please explain more about mmc partconf.

when I flash the full image in download mode where to u-boot is flashed ?

what actully happend when I did the dd to seek=32 ? it was written to another location ?

this issue is not clear to me and I cannot find much information about it in the linux user manual.

Thanks

Roy

Re: flash u-boot from uboot using ums

dvlogic — Mon, 25 Jul 2022 19:14:36 GMT

The dd command will write into the main raw eMMC memory partition area. The eMMC will also have a boot partition. I believe when you use the uuu command, it will write the u-boot into the boot partition and enable it in the eMMC part configuration.

u-boot=> mmc partconf 2
EXT_CSD[179], PARTITION_CONFIG:
BOOT_ACK: 0x0
BOOT_PARTITION_ENABLE: 0x1
PARTITION_ACCESS: 0x0

The second 0 in the "mmc partconf 2 0 0 0" will disable the eMMC from booting from the boot partition and instead boot from the main partition.

Hope this helps - by no means am I an expert, I've just figured most of this out through reading and trial and error.

Re: flash u-boot from uboot using ums

razriel — Mon, 25 Jul 2022 19:23:54 GMT

thanks. it worked.

now I am able to see my changes in the print.