[U-Boot] [PATCH 8/8] board support for palm treo 680

[Marek Vasut]

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 <mikedunn at newsguy.com>

I dunno about the userland too, it might go into tools/ and be unified to all 
DoCG4 devices. And also make sure to use #define[space] isntead of #define[tab] 
in the config file.