On 13:30 Mon 03 Sep , Sascha Hauer wrote: > On Mon, Sep 03, 2012 at 12:55:34PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote: > > On 12:32 Mon 03 Sep , Juergen Beisert wrote: > > > Hi all, > > > > > > currently I'm working on the difficult process to make an i.MX35 SoC boot from > > > an externally connected NAND device. > > > > > > Nothing special with it, only the NAND flash controller in the i.MX35 (also in > > > i.MX25, i.MX27 and i.MX31) is braindamaged broken. This controller loses the > > > factory bad block markers when used without a workaround and losing these > > > markers is a _really_ bad idea. > > > > > > But to use the workaround on these SoCs it needs a complicated preparation of > > > the NAND. Doing it manually is very error prone. And this kind of preparation > > > has to be kept when the system should be updated and so on. Not easy to > > > explain and so much more chances for the user to brick the system while the > > > update process. > > > > > > This makes me think about a dedicated command which is responsible to make the > > > target bootable and does all the (more or less complicated) steps to ensure > > > the next time it gets powered it's able to boot again. > > > > > > There are more architectures which needs a complicated setup to be able to > > > boot it from some kind of externally connected devices like NAND or eMMCs for > > > example. Some needs special NAND checksums only for the bootloader, others > > > needs to keep the partition table even if the bootloader gets updated and so > > > on. > > > > > > Would it be possible to share one command (or one group of commands) by all > > > architectures? And each architecture adds its special code to the command? > > > > > > What kind of setup procedures we must cover with such a command? > > > > > > My examples: > > > > > > - for the Freescale i.MX SoCs with the broken NFC we must write the bootloader > > > in a different way than all the remaining data into the NAND device > > > - for the Samsung S36410 we must save the factory bad block markers first to > > > support booting from NAND as its internal ROM expects the checksums at a > > > strange offset in the OOB area > > On some ST SoC it's the same I think we do not need any command we just need > > to specify it as mtd level for a specific mtd part > > A command has the advantage that for example we could also check for > valid images before flashing them (does it have a correct barebox > header?). This could be checked before actually erasing a sector. > Also, flashing boot images is not limited to mtd devices, it could also > be mmc, or for OMAP, not a device at all but a file inside a FAT on SD > card. for this part I agree but for the oob we must handle it at mtd level otherwise the mtdcore will taint on bad ecc as example Best Regards, J. _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
