Roland Paterson-Jones writes:
> I notice that there is some mention of an S3 card in the diary, but what
> scares me is the mention that an x86 emulator had been compiled into the
> image to get it working. What was wrong with manual initialization?
I used to do my own initialisation, but there were problems with doing
this. Some of the settings had to be guessed and trialed, and it was
never perfect. By this, I mean I had white text on grey background.
In addition, dispite there being links on the card to tell the chip
what type of video memory the board contained, these links were set
wrong, so the only accurate source of this information was presumably
buried in the BIOS.
The PCI standard allows two different types of ROM format - one is based
on Forth, the other is x86 machine code. Unfortunately, most cards
contain x86 machine code.
Therefore, the only reliable way to initialise such cards is to actually
run the BIOS, which, in this case is the x86 code.
The only other way is to be limited to just one video card with one
fixed initialisation method. In an industry where things go obsolete
very quickly, this IMHO is not a good answer.
Therefore, I took the decision to include an x86 emulator core into the
EBSA285 BIOS so that most video cards could and should work.
Currently, the emulator is not all that fast, mainly because its running
in the BIOS without the D-cache and writebuffers on. However, I am
considering turning these on for better performance.
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|_____| ------------------------------------------------- ---+---+-
| | Russell King [EMAIL PROTECTED] --- ---
| | | | http://www.arm.linux.org.uk/ / / |
| +-+-+ --- -+-
/ | THE developer of ARM Linux |+| /|\
/ | | | --- |
+-+-+ ------------------------------------------------- /\\\ |
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