Re: [ECOS] SH3 and Redboot [newbie]

[Jonathan Larmour <jlarmour at redhat dot com>]

Paul Krushka wrote:
> 
> Hi
> 
> Our engineer has designed a circuit with a 7077 SH3 ship, 8Mb RAM some flash
> and a 4Mb boot EPROM.  I would like to get linux booting using RedBoot as
> the bootloader.  My first step will be to get RedBoot working, what
> information should I get from the engineer?
> 
> He is not really interested in getting linux going on this board but is
> willing to supply me with all the memory addresses that I think I will need
> and also help with the schematic circuit.
> 
> Is anyone willing to give me some pointers on where to start...ie  what
> memory addresses or information do I need for RedBoot to load?
> 
> I can programme the EPROM with an external programmer to load RedBoot,  the
> engineer has said the EPROM is mapped at 0 so I assume I need to modify
> RedBoot to setup the chip registers etc after the CPU jumps to address 0...

For starters, you should get the memory map, details of all devices you
have on the board, and inparticular the details about some form of
diagnostic I/O, although for the SH3, you will probably be able to use the
SCI/SCIF. The trickiest part will probably be configuring whatever RAM you
have on the board, so be sure you have the details about that.

Perhaps the best guide is to look at an existing SH3 platform HAL and see
what is needed. Try the edk7708.

Jifl
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