Status of ATA support

[Marco Gerards <mgerards@xs4all.nl>]

Hi,

A while ago I added support for ATA support.  It wasn't complete yet,
but I rather have this in CVS than rotting on my harddisk.  Besides
that, it isn't *that* bad.  I will describe the outstanding issues
below.

First of all, this is mainly for i386-linuxbios.  On i386-pc we have
to disable biosdisk support because ata.mod and biosdisk.mod do not
like eachother :-).  Perhaps disk access via the BIOS will not be
possible/safe anymore after loading ata.mod.

PCI devices are not supported *yet*.  Same for controllers 3 and 4.  I
will work on this.

The code to detect the type of controller (PATA, SATA, PATAPI, SATAPI)
really sucks.  I will have a look at this.

There is no code to detect the amount of sectors for a CDROM.  I will
write this eventually.  Patches are more than welcome!

The biggest problem is that grub_get_rtc is used to measure how long
we have to wait for the hardware to settle.  This function return the
amount of ticks (1/18th of a second), this resolution is not
acceptable.  It will result in large delays in ata.mod because it will
wait at least 1/18th of a second on i386-pc.

For i386-linuxbios we still need grub_get_rtc.

More about this on my blog:
http://www.mgerards.net/blog/?p=34

--
Marco