Dear Mike Dunn, > On 04/11/2013 12:20 PM, Marek Vasut wrote: > > Dear Mike Dunn, > > > >> A quick overview of u-boot implementation on the treo 680... > >> > >> The treo 680 has a Diskonchip G4 nand flash chip. This device has a 2k > >> region that maps to the system bus at the reset vector in a NOR-like > >> fashion so that it can be used as the boot device. The phone is shipped > >> with this 2k region configured as write-protected (can't be modified) > >> and programmed with an initial program loader (IPL). At power-up, this > >> IPL loads the contents of two flash blocks to SDRAM and jumps to it. > >> The capacity of the two blocks is not large enough to hold all of > >> u-boot, so a u-boot SPL is used. To conserve flash space, these two > >> blocks and the necessary number of subsequent blocks are programmed > >> with a concatenated spl + u-boot image. That way, the IPL will also > >> load a portion of u-boot proper, and when the spl runs, it relocates > >> the portion of u-boot that the IPL has already loaded, and then resumes > >> loading the remaining part of u-boot before jumping to it. > >> > >> The default_environment is used (CONFIG_ENV_IS_NOWHERE) because I didn't > >> think that having a writable environment was worth the cost of a flash > >> block, although adding it would be straightforward. I abuse the > >> CONFIG_EXTRA_ENV_SETTINGS option to specify the usbtty for the console > >> (CONFIG_SYS_CONSOLE_IS_IN_ENV). > >> > >> Support for the LCD is included, but currently it is only useful for > >> displaying the u-boot splash screen. But if u-boot is built without the > >> usbtty console, it does display the auto-boot progress nicely. > >> > >> Signed-off-by: Mike Dunn <miked...@newsguy.com> > > > > I think the tool shall really go as a separate patch. Besides, can the > > tool not be implemented as a part of u-boot's mkimage infrastructure? > > OK, I can make the flash_u-boot utility (which writes u-boot to the flash > boot blocks) a separate patch. > > As for making it part of mkimage... I didn't really consider that because > based on my (limited) knowledge, I figured they are unrelated. As I > understand it, mkimage creates an OS image file that u-boot can parse and > load. flash_u-boot is a utility that performs the task of writing u-boot > itself to flash.
It can create an bootloader image that can be written to flash using standard mtd utilities. Does this not cut it for you? Why do you need a separate flasher, because the G4 is special ? > I figured that mine was a special case, since u-boot must be written in a > special format (redundant pages) and in a special manner (alternate 4k > regions skipped), with the flash device in a special mode, and so it can > not be done in the normal manner; e.g., 'nandwrite' from mtd-utils, or its > u-boot 'nand write' equivalent, even if you first ran the u-boot image > through a separate utility that simply converted the format of the image. > > Hope that makes sense. Any insight appreciated. I'll take a look at > what's in the tools directory. I see ... so the G4 is such a horrible beast :( OK Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot