[U-Boot] eMMC boot partition support in uboot
Hi guys,
Recap: I am trying to boot MLO + uboot from eMMC boot partition on DRA7xx_EVM eval platform. SW-Baseline: uboot p-ti-uboot-2013.04 & p-ti-linux-3.8.y from omapzoom.
What happens so far: 1. I am able to dd the MLO into /dev/mmcblk1boot0 (need to echo 0 to force_ro). 2. I am able to setup the eMMC to enable the ROM BootLoader (RBL) to boot the "Alternate boot mode" using mmc-utils by setting: BOOT_BUS_WIDTH Register (EXT_CSD [177]) = 0x15 (needed to set DDR mode at boot) PARTITION_CONFIG Register (EXT_CSD [179]) = 0x48 (needed to enable booting from boot partition)
Up to this point I am able to get this response when booting the MLO from the eMMC boot partition
U-Boot SPL 2013.04-00366-g5f72750-dirty (Dec 03 2013 - 21:40:19) DRA752 ES1.0 OMAP SD/MMC: 1 spl: wrong MMC boot mode spl_mmc_load_image: spl_boot_mode = 0 (MMCSD_MODE_UNDEFINED) spl_boot_device = 6 (BOOT_DEVICE_MMC2) ### ERROR ### Please RESET the board ###
3. I realize that the MLO contents (using uboot/tools/omapimage?) needed to say MMCSD_MODE_RAW for my platform. I am bypassing this problem by by hard coding the response arch/arm/cpu/armv7/omap-common/boot-common.c::spl_boot_mode() to always says MMCSD_MODE_RAW. This seems to work and I am past the hang() code.
4. Now, MLO is ready to (raw) load uboot binary from the eMMC boot partition (i.e. /dev/mmcblk1boot0). Unfortunately, at this point I don't know how to make the platform recognize the eMMC boot partitions. I think they are not modelled yet in uboot. Only the User-Data-Area (UDA) is recognized in uboot (called mmc 1)
My understanding is that for mmc boot partition recognition, we need to extend drivers/mmc/omap_hsmmc.c::omap_mmc_init() to be able to handle it? or is there a better place?
Question 1: Is my understanding of the current state all correct?
Question 2: How should I proceed to add support for /dev/mmcblk1boot0 into uboot? I am thinking the solution should self parse the ext_csd to find out which boot partition is active and then load the uboot raw from a known offset there.
I saw the linux patch adding eMMC boot partition at: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/Docume...
But I don't see how to adapt it into uboot...
Thanks for everyone's time.
On Thu, Dec 05, 2013 at 01:46:40PM -0500, Richard Retanubun wrote:
Hi guys,
Recap: I am trying to boot MLO + uboot from eMMC boot partition on DRA7xx_EVM eval platform. SW-Baseline: uboot p-ti-uboot-2013.04 & p-ti-linux-3.8.y from omapzoom.
Please note that this list is for the mainline U-Boot tree, and to contact your TI reps for help with the TI trees. I'm answering in general since I know how the mainline code works, and what I suspect needs doing there in general to allow what you want to work:
[snip]
- I realize that the MLO contents (using uboot/tools/omapimage?) needed to say MMCSD_MODE_RAW for my platform. I am bypassing this problem by by hard coding the response arch/arm/cpu/armv7/omap-common/boot-common.c::spl_boot_mode() to always says MMCSD_MODE_RAW. This seems to work and I am past the hang() code.
It's possible that the ROM simply doesn't support a dos-style partition table and a FAT partition on the eMMC boot partition so the right answer here is to do what you're doing and hard-code raw only. I strongly suspect this to be true, even.
- Now, MLO is ready to (raw) load uboot binary from the eMMC boot partition (i.e. /dev/mmcblk1boot0). Unfortunately, at this point I don't know how to make the platform recognize the eMMC boot partitions. I think they are not modelled yet in uboot. Only the User-Data-Area (UDA) is recognized in uboot (called mmc 1)
Not quite true, no. You'll need code similar to what we have in common/env_mmc.c to switch the partition to the boot partition.
On 05/12/13 02:09 PM, Tom Rini wrote:
On Thu, Dec 05, 2013 at 01:46:40PM -0500, Richard Retanubun wrote:
Hi guys,
Recap: I am trying to boot MLO + uboot from eMMC boot partition on DRA7xx_EVM eval platform. SW-Baseline: uboot p-ti-uboot-2013.04 & p-ti-linux-3.8.y from omapzoom.
Please note that this list is for the mainline U-Boot tree, and not to contact your TI reps for help with the TI trees. I'm answering in general since I know how the mainline code works, and what I suspect needs doing there in general to allow what you want to work:
Sorry if I appear as abusing the mailing list. That was not the intent and I will stop doing it for this issue.
The main reason I am including the mailing list is to share notes on what had to be done even to get the MLO loaded and booting in alternate boot mode.
I realize my problem may be ti tree specific, but I think the EXT_CSD settings in the eMMC I found is of value on many other CPUs booting over eMMC.
[snip]
- I realize that the MLO contents (using uboot/tools/omapimage?) needed to say MMCSD_MODE_RAW for my platform. I am bypassing this problem by by hard coding the response arch/arm/cpu/armv7/omap-common/boot-common.c::spl_boot_mode() to always says MMCSD_MODE_RAW. This seems to work and I am past the hang() code.
It's possible that the ROM simply doesn't support a dos-style partition table and a FAT partition on the eMMC boot partition so the right answer here is to do what you're doing and hard-code raw only. I strongly suspect this to be true, even.
- Now, MLO is ready to (raw) load uboot binary from the eMMC boot partition (i.e. /dev/mmcblk1boot0). Unfortunately, at this point I don't know how to make the platform recognize the eMMC boot partitions. I think they are not modelled yet in uboot. Only the User-Data-Area (UDA) is recognized in uboot (called mmc 1)
Not quite true, no. You'll need code similar to what we have in common/env_mmc.c to switch the partition to the boot partition.
I'll have a look at that then, Tom. Thank you for your time.
participants (2)
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Richard Retanubun -
Tom Rini