[resolved] Booting from SDHC and therefore chrooting on USB disk

[maisondouf]

As the boot on usb disk is hazardous and I want to be sure than the plug always run after a general power breakdown, I have a question.

I would try to put uImage and uInitrd in a SDHC (mmcblk0p1) and after loading by u-boot these images would load the root-fs from an external USB disk with a partition sda1 for /root and sda2 for swap.

Perhaps, this method can solve the boot issues.


Is there anyone to help me for this try ?

[NewIT_Marcus]

The most common issue regarding booting from USB seems to be hdd spin-up. That issue would occur regardless of whether you boot (everything) from USB, or just mount the rootfs, or some parts of it, after a successful first stage. A quick search on the plug computer forum for "USB boot spin" lists many threads where this is discussed.

[maisondouf]

thanks

[maisondouf]

I've found this

To boot on USB external drive you must use an SD Card too.
You just need to copy uInitrd and uImage from /boot of you debian installation to the SD Card.
You had to configure the uBoot to load uInitrd and uImage from SD Card.

Then, kernel loaded will correctly access to your USB external drive and boot your Debian System with success.

You'll only have to copy the uInitrd and uImage after each Debian kernel update from USB to SD Card.

To be tried....

[maisondouf]

It is really marvellous !

I never have seen my plug booting so quickly.

I have installed Debian with net-install on an USB disk, I have formatted a SDHC card with a little ext2 partition at the beginning, I have copied all the files in the boot partition of the USB disk in it.

The uboot parameters here:

setenv bootargs_console 'console=ttyS0,115200n8'
setenv bootroot_usb 'root=/dev/sda2 rootdelay=10 rootfstype=ext3'
setenv bootload_mmc 'mmcinit; ext2load mmc 0 0x01100000 /uInitrd; ext2load mmc 0 0x00800000 /uImage'
setenv dualboot 'setenv bootargs $(bootargs_console) $(bootroot_usb); run bootload_mmc; bootm 0x00800000 0x01100000'
setenv bootcmd 'run dualboot'
saveenv
boot

so gooooood !