Hi Guys, thanks for the responses. my comments are below.
On 20/11/13 05:39 PM, Shankar Rao wrote:> On 11/20/2013 04:27 PM, Richard Retanubun wrote:
Hi Richard, Are you trying to boot Android kernel or Linux kernel? Building u-boot with android config will give you access to fastboot which can help you partition the eMMC and boot out of it.
I am trying to boot Linux kernel. The plan is to put MLO and uboot in the eMMC's boot partition and a GPT partitioned linux in the user data area.
I think there are some errata in the ROM bootcode about booting over QSPI1, I am concerned that I am hitting another errata condition. Can you help me confirm this?
On 21/11/13 12:39 AM, Michael Pratt wrote:
Hi Richard,
On Wed, Nov 20, 2013 at 5:27 PM, Richard Retanubun richardretanubun@ruggedcom.com wrote:
However, the CPU does not print anything back on the console...
The only way I can get raw eMMC boot mode to work is if I put the MLO on /dev/mmcblk1 (which is the user data area).
I have not seen a reference manual for dra7xx, so this may not apply, but it is worth noting that many SoCs that support booting from eMMC do not actually use the boot mode, and simply boot directly from the user data area. The boot mode is described in the eMMC spec in a section titled "Boot operation mode" (Section 7.3 in eMMC 4.4). Basically, it provides a different initialization sequence that will sequentially read out the partition selected in CONFIG_PARTITION. If the SoC is not utilizing this boot mode, it may unconditionally read from the user data area.
Yep. These are the sequence I am trying to do (the "Alternate boot operation")
Does the MLO for raw boot mode needs to be different that the MLO for raw user data area?
If both MLO and U-Boot are to be in the boot partition, booted using eMMC boot mode, MLO will likely need to behave differently in order to correctly read U-Boot. Boot mode sequentially reads out the selected partition, without using the standard commands, so MLO will need to understand this and perform the appropriate clocking of the eMMC. I am unsure if there is currently support for that.
I am aware that the MLO will have to behave differently. But I expect that at least the beginning (version printing) is common. I am trying to use that as a quick-and-dirty test to confirm the SoC's ability to boot over eMMC boot partition.
I am aware that there is no support in denx mainline. In the ti omapzoom repo/u-boot there are code that looks hopeful. (ref: /drivers/mmc/spl_mmc.c::spl_mmc_load_image_raw())
Once I can get the SoC to boot the MLO, I plan to use that for the MLO to find and load uboot.
Hopefully this is helpful! Michael Pratt
Thanks for both your time.