OMAP-L138: Bootloading from NAND with Bad Sectors

Benjamin Michaud

Expert 1825 points

Part Number: OMAP-L138
Other Parts Discussed in Thread: OMAPL138

Hi,

We're working with the OMAP-L138 and will be booting from NAND flash at startup up.

We're also using TI RTOS and not Linux with this project right now.

When it comes to putting an image into NAND flash it seems that TI offers a tool to do this.

However, once it comes time to update the firmware in the field we don't want to have to use a special software tool to perform this.

What we will need to do is have our main program flash NAND with the new image.

My question is if we come across a block in NAND that has a corrupt bit(s), what algorithm is used by the bootloader in the OMAP-L138 to detect this and work around it?

We need to follow the same algorithm so that at boot up the bootloader in the OMAP-L138 can make proper sense of what is in NAND flash in order to load it.

Thanks,

Ben

over 3 years ago

0 Jianzhong Xu over 3 years ago

TI__Mastermind 40225 points

Hi Ben,

Processor-SDK for TI RTOS only supports MMCSD SBL as documented here. It doesn't have support for NAND flashing.

You can still use the omap-l138 starterware which has NAND SBL. However, we don't support the starterware anymore. You can refer to Using the OMAP-L132/L138 Bootloader (section 6.4 NAND Flash Boot) for more information about NAND flashing.

Regards,

Jianzhong

+1 Jianzhong Xu over 3 years ago in reply to Jianzhong Xu

TI__Mastermind 40225 points

Hi Ben,

I looked into the starterware code (download from omap-l138 starterware) and found the following in OMAPL138_StarterWare_1_10_04_01\bootloader\src\armv5\omapl138\bl_platform.c:

    /* Init the NAND Device Info */
    nandInfo->opMode                        = NAND_DATA_XFER_MODE;
    nandInfo->eccType                       = NAND_ECC_ALGO_RS_4BIT;

So the OMAP-L138 NAND bootloader uses Reed-Solomon code for error correction. You can find the implementation in OMAPL138_StarterWare_1_10_04_01\nandlib\nand_emifa2.c:

static void EMIFAReedSolomonECCCalculate(NandInfo_t *nandInfo, unsigned char *ptrEccData)

Hope this helps.

Regards,

Jianzhong

0 Benjamin Michaud over 3 years ago in reply to Jianzhong Xu

Expert 1825 points

Thanks Jianzhong,

That is what we were looking for!

Ben

Processors

Processors forum

OMAP-L138: Bootloading from NAND with Bad Sectors