• Mike Dunn's avatar
    pxa: add support for palmtreo680 board · 0dc0e846
    Mike Dunn authored
    This patch adds support for the Palm Treo 680 smartphone.  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: default avatarMike Dunn <mikedunn@newsguy.com>