This page is how to recover ("unbrick") a broken BeagleBoard. It should help you if you messed your boot configuration and BeagleBoard doesn't boot any more the normal way ("bricked").
Normally, if you boot from MMC, you will get something like
in terminal program connected to UART (115200 8N1). This is output from OMAP3's bootrom while scanning the UART for boot source before trying to boot from MMC card. If you don't get this, but want to boot from MMC, most probably bootrom doesn't reach the MMC boot stage any more. If you played with NAND before getting this, most probably NAND contains some broken content.
What has happened?
Depending on user button OMAP3 on BeagleBoard uses different boot order. Normal order if user button isn't pressed at power up is boot from
NAND -> USB -> UART -> MMC
in this order. Depending on the boot medium (e.g. MMC) this might fail if something bad is in NAND flash which confuses OMAP3 bootrom thus stopping it to reach MMC boot stage.
This might happen if you e.g. mess your NAND, e.g. something went wrong using Steve's NAND flash procedure.
What to do now?
First, we have to press user button at power up to switch boot order to
USB -> UART -> MMC -> NAND
to have option to boot from other sources than broken NAND (which is first if user button is not pressed).
Then, there are three options to boot from:
Below, MMC and USB recovery will be done in detail. Goal of all ways is to get an U-Boot prompt again to erase the bad NAND content.
MMC recovery should be straight forward. Press user button at power up and according to above boot order MMC boot is before NAND. With this, we should be able to boot as we did without pressing the user button before bricking the board. But:
There are some broken MLO (x-loader) out there which fail to boot if something wrong is in NAND. E.g.:
...40T......... Texas Instruments X-Loader 1.41 Starting on with MMC Reading boot sector 150832 Bytes Read from MMC Starting OS Bootloader from MMC... U-Boot 1.3.3 (Jun 20 2008 - 17:06:22) OMAP3530-GP rev 2, CPU-OPP2 L3-165MHz OMAP3 Beagle Board + LPDDR/NAND RAM Configuration: Bank #0: 80000000 128 MB Bank #1: 88000000 0 kB NAND: NAND device: Manufacturer ID: 0x2c, Chip ID: 0x01 ( AND 128MiB 3,3V 8-bit) NAND bus width 16 instead 8 bit 0 MiB <hang, no prompt>
This seems to happen with both MLO's from Beagle source code page (381MHz and 500MHz one) independent of U-Boot version.
Thus, you have to use a special (?) MLO for recovery to get a U-Boot prompt. Replacing MLO used above on MMC/SD card with this recovery MLO we get a U-Boot prompt while pressing the user button at power up:
...40T......... Texas Instruments X-Loader 1.41 Starting on with MMC Reading boot sector 150832 Bytes Read from MMC Starting OS Bootloader from MMC... U-Boot 1.3.3 (Jun 20 2008 - 17:06:22) OMAP3530-GP rev 2, CPU-OPP2 L3-165MHz OMAP3 Beagle Board + LPDDR/NAND RAM Configuration: Bank #0: 80000000 128 MB Bank #1: 88000000 0 kB NAND: 256 MiB In: serial Out: serial Err: serial Hit any key to stop autoboot: 0 OMAP3 beagleboard.org #
U-Boot version doesn't seem to matter.