Question regarding MMC uboot

[Jules]

I've downloaded the alternative MMC uboot image from https://github.com/hehopmajieh/olinuxino-a13 and before I install it was wondering how it was configured?

1. If no MMC is present, will it boot from the built-in flash?
2. What file is it booting from the MMC card?  Does it support initrd, or does it just mount the card as root?

Obviously the defaults can be overridden via the console, but after a recent hardware failure I find myself in the situation of not having a PC with a serial port in the office for the first time, and haven't yet purchased a USB-serial converter.

[HeHoPMaJIeH]

Hi, this image is obsolete, you can download u-boot from hno git repo :
https://github.com/hno/uboot-allwinner.git
After downloading compile it using  provided instructions :
https://github.com/hno/uboot-allwinner/wiki

This version of u-boot boots direct from mmc using mmc spl, and no need to "hack" device

[murerten]

Hi,

I downloaded the u-boot from https://github.com/hno/uboot-allwinner.git and compiled it. Then I format a 2GB sdcard like this:

1. partition (there is a 10MB offset from start) 200MB fat32
2. partition ~1800MB ext4

I copied android filesystem to 2. partition; the files in /dev/block/nanda to 1. parition.

Then I did the dd commands:
dd if=spl/sunxi-spl.bin of=/dev/sdc bs=1024 seek=8
dd if=u-boot.bin of=/dev/sdc bs=1024 seek=32

Now if I plug the sdcard nothing boots and uart sends crap all the time. But nand boots ok.

I'm new on this u-boot thing so I don't know what to do to make a bootable android sdcard. Are there other things I have to make? I know that I need to edit android init.rc to change those nand to mmcblk0. But I think for now there is problem on u-boot.

Thanks

[HeHoPMaJIeH]

Hi,

I downloaded the u-boot from https://github.com/hno/uboot-allwinner.git and compiled it. Then I format a 2GB sdcard like this:

1. partition (there is a 10MB offset from start) 200MB fat32
2. partition ~1800MB ext4

I copied android filesystem to 2. partition; the files in /dev/block/nanda to 1. parition.

Then I did the dd commands:
dd if=spl/sunxi-spl.bin of=/dev/sdc bs=1024 seek=8
dd if=u-boot.bin of=/dev/sdc bs=1024 seek=32

Now if I plug the sdcard nothing boots and uart sends crap all the time. But nand boots ok.

I'm new on this u-boot thing so I don't know what to do to make a bootable android sdcard. Are there other things I have to make? I know that I need to edit android init.rc to change those nand to mmcblk0. But I think for now there is problem on u-boot.

Thanks

it's not normal to see only crap on UART port, try to use different uSD ot fill it with zeroes and try again

[murerten]

Ok, thanks. I changed my mind on storing the root on sdcard. But how about using the android on nand (hopefully mounting it read-only) and mounting the /data folder on external sdcard? Is this possible and logical? I want to make root filesystem more robust as nand has a limited erase cycle, and the data can be on sdcard, possibly ext4 and with logging enabled? If the sdcard fails I can change it.