On Tue, Nov 10, 2020 at 12:57:09PM +0000, André Przywara wrote: > On 10/11/2020 12:38, Tom Rini wrote: > > Hi Tom, > > > On Sun, Nov 08, 2020 at 03:48:23PM +0000, André Przywara wrote: > >> On 08/11/2020 14:59, Peter Robinson wrote: > >> > >> Hi, > >> > >>> On Sun, Nov 8, 2020 at 1:14 PM Andre Przywara <[email protected]> > >>> wrote: > >>>> > >>>> The eMMC standard describes the concept of boot partitions, consisting > >>>> of two storage areas separate from the main user data partition. > >>>> The Allwinner BootROM supports loading SPL/Boot0 from such a boot > >>>> partition, if that is configured in the eMMC device [1]. > >>>> > >>>> To load U-Boot proper along with the SPL from there, currently this > >>>> requires to enable CONFIG_SUPPORT_EMMC_BOOT, and this means that this > >>>> build won't boot from the normal eMMC user partition anymore. > >>>> Also the raw MMC sector offset needs to be adjusted manually, preventing > >>>> a boot from an SD card. > >>>> > >>>> This series introduces automatic detection of eMMC boot partition boot. > >>>> Patch 3/5 automates the raw MMC sector offset decision, allowing such > >>>> a build to also boot from an SD card. > >>>> Unfortunately the BootROM does not mark an eMMC boot partition boot > >>>> differently from the normal eMMC user data partition boot, so patch 4/5 > >>>> introduces a function that repeats the BootROM algorithm, so that the SPL > >>>> comes to the same conclusion as the BootROM. This allows to build one > >>>> single image that boots from everywhere: eMMC user data, eMMC boot, > >>>> SD card, SPI flash. > >>>> Patch 1/5 contains a bugfix that's needed in a later patch, patch 2/5 > >>>> extends the generic spl_mmc_boot_mode() interface to make 4/5 feasible. > >>>> > >>>> Without enabling CONFIG_SUPPORT_EMMC_BOOT, the AArch64 SPL grows by > >>>> 92 bytes, ARMv7 grows by 36 bytes. With enabling the feature, the size > >>>> goes up by 444 bytes (AArch64) and 260 bytes (ARMv7). > >>>> Even for AArch64 this is still 4.5 KB below the SPL limit, so patch 5/5 > >>>> enables this new mechanism for some boards I could test this on. > >>>> > >>>> Please have a look and test this if you have a board with eMMC. > >>>> I put installation instructions into the linux-sunxi Wiki: > >>>> http://linux-sunxi.org/Bootable_eMMC > >>> > >>> It would probably be good to put that link in the local Allwinner docs > >>> so it's easier for people to find. > >> > >> Yeah, actually as you mention it: > >> There does not seem to be some generic README.sunxi file where this > >> would belong to. > >> > >> Jagan: would it make sense to create one, and describe how to get U-Boot > >> into the devices (SD card, eMMC, SPI flash, FEL)? That could move some > >> parts of README.sunxi64 out of there, since they apply to all Allwinner > >> devices. > >> > >> If people agree that this is the right thing to do, I would be happy to > >> send a patch. > > > > Well, rST file in doc/boards/ and all of that, but, yes please. > > Ah, thanks for the pointer, looks good. > Do we accept symlinks in the tree? There are quite some references to > board/sunxi/README.sunxi64 out there. Or shall I keep a stub instead?
As there's external references to the README file, yes, please stub it out pointing people to the new rST file. Thanks! -- Tom -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/linux-sunxi/20201110130816.GC5340%40bill-the-cat.
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