From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ziyuan Date: Tue, 14 Mar 2017 18:14:20 +0800 Subject: [U-Boot] accessing eMMC boot partitions from U-Boot In-Reply-To: <0328feca-f840-7eaa-ed10-9173f843914d@wwwdotorg.org> References: <3d6cdf04-290a-3588-2e44-6dbc2f618c89@wwwdotorg.org> <58C73F3C.3010601@rock-chips.com> <0328feca-f840-7eaa-ed10-9173f843914d@wwwdotorg.org> Message-ID: <58C7C27C.4000100@rock-chips.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 Stephen, On 03/14/2017 12:41 PM, Stephen Warren wrote: > On 03/13/2017 06:54 PM, Ziyuan wrote: >> hi Stephen, >> >> On 03/14/2017 05:49 AM, Stephen Warren wrote: >>> On 03/13/2017 03:34 PM, Tim Harvey wrote: >>>> Greetings, >>>> >>>> I'm working with some boards with eMMC FLASH and understand that I can >>>> set the fields of the PARTITION_CONFIG with the 'mmc partconf' command >>>> to specify what partition is used for boot. Once I do that to set the >>>> boot0 partition for example, how can I access that partition from >>>> within u-boot via mmc read/write? In Linux the kernel provides access >>>> to user/boot0/boot1/rpmb via different devices, but I don't see u-boot >>>> doing that. >>> >>> The "mmc dev" command can be used to select which MMC device to >>> operate on. The "typical" command "mmc dev 0" selects the main >>> partition on MMC device 0 for later MMC-specific commands such as "mmc >>> read". You can add an extra parameter to that command to request a >>> specific HW partition, e.g. "mmc dev 0 1" selects boo0 of MMC device 0 >>> and "mmc dev 0 2" selects boot1. >> >> The 4th of "mmc dev 0 1" is the *software* partition index, not the hw >> partition index. AKA eMMC has four partitions: user >> data/boot0/boot1/rpmb, I think Tim wanna to boot from other partition, >> like boot0, right? > > The fourth parameter is the HW partition number. See how cmd/mmc.c's > do_mmc_dev() passes this value to blk_select_hwpart_devnum(), then to > blk_select_hwpart(). Thanks, it's my fault. > > >