[ECOS] SH2 porting

[Jesper Skov]

[please make sure to CC the list]

>>>>> "John" == John M Mills <jmills@tga.com> writes:

John> Jesper - On 9 Jun 2000, Jesper Skov wrote:

>> Beware that there's likely to be a bit of work to do in order to
>> integrate support for the SH2 variant. Presently the architecture
>> code is primarily SH3 specific. When it's clear how much can be
>> shared between the SH2 and SH3 variants, it will be possible to
>> partition things in a better way.

John> Thanks for the comment. I really have no idea of the amount of
John> work involved, and expected it related primarily to
John> board-support, on-board-peripheral usage, and those parts of
John> eCos coded in SH-3 assembly.  I had inferred from listings of
John> cross-gcc builds that 'gcc' might build the same code for SH-2
John> and SH-3.

User level stuff will be the same. But there might be need for
different interrupt/exception handling implementations, and probably
new serial drivers.

It _could_ be fairly stright forward to do - but I've never taken the
time to go through the SH2 (or SH1) manuals to prepare the SH HAL for
this. Variants HALs came after the initial port - I've just been
waiting for a new SH2/1 port so I could split up the HAL in variants.

Jesper