From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Retanubun Date: Thu, 21 Nov 2013 09:02:55 -0500 Subject: [U-Boot] dra7xx: booting from eMMC raw boot partition In-Reply-To: References: <528D3766.5010007@ruggedcom.com> Message-ID: <528E128F.5050605@ruggedcom.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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 > 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.