about BOOT_IDE

[Terry B. Chen]

Dear all:
         I decide to elf_boot use BOOT_IDE, because the rom is too small
to settle a big kernel that support.
Can some one tell me the usage of the options such as ONE_TRACK and how
to put the elf to hard disk, I think it must be dangerous, it seem to
read the sector directly. Someone can teach me a little?

Best regards 
Terry chen

[Adam Agnew]

Hi Terry,
This was actually discussed just yesturday as well, so in the interest of
not covering the subject again so soon... Please see the thread
starting with:

----
From: Deepak Kotian 
To: [e-mail]
Subject: Burning BIOS on FLASH ROMS, is the kernel also needs to burnt on
it
---

For three other options for booting from hard disk. Your actually looking
at the fourth option, which i forgot earlier. Also keep in mind that using
a flash disk, like perhaps a compact flash card on an ide adaptor
(cwlinux.com sells such a beast) you can keep your lightning fast boot up
speeds!

If you don't want to put your kernel image on the beginning sectors of
your hard disk, your easiest option is probably etherboot 5.0.6 + the
polled ide patch.

- Adam Agnew

On Thu, 10 Apr 2003, Terry B. Chen wrote:
> Dear all:
>          I decide to elf_boot use BOOT_IDE, because the rom is too small
> to settle a big kernel that support.
> Can some one tell me the usage of the options such as ONE_TRACK and how
> to put the elf to hard disk, I think it must be dangerous, it seem to
> read the sector directly. Someone can teach me a little?
>
> Best regards
> Terry chen

[Steve Gehlbach]

Terry B. Chen wrote:
> Dear all:
>      I decide to elf_boot use BOOT_IDE, because the rom is too small 
>
> to settle a big kernel that support.
>
> Can some one tell me the usage of the options such as ONE_TRACK and how 
> to put the elf to hard disk, I think it must be dangerous, it seem to 
> read the sector directly. Someone can teach me a little?

See pcchips787.config in util/config for complete configuration.

option BOOT_IDE=1
This enables booting from IDE, the file to use is linux.bin.gz:

option IDE_BOOT_DRIVE=2
If you do not use drive 0  (default), then you can set which drive to 
boot; (0,1,2,3) are the four standard PC drives:

option ONE_TRACK=32
The linux.bin.gz file is put in raw form at partition 1, ie, the first 
partition on the disk.  This is located just past the partition table. 
The partition table size varies, it is "one track" from the beginning of 
the disk.  "one track" in c/h/s notation is "s" or the number of sectors 
per track.  ONE_TRACK is in sectors, the software multiplies by 512. 
Most disks are 63 sectors per track (the default), but my CF is 32 
sectors per track.  eg, the partion table is 63x512 or 32x512 bytes.

You can partition your disk as you want, but linux goes raw in partition 
1; just make sure partition 1 is big enough, not a problem on today's 
disks.  You could put the linux root file system on partition 2, for 
example.  In pcchips787.config, I put the linux root file system on IDE 
0, partition 2 (I was experimenting with linux in partition 1), but I 
eventually put linux on drive 2 using CF.  You are right, copying of 
linux.bin.gz raw to the partition is dangerous, and something like "cat 
linux.bin.gz > /dev/hda1" will definitely screw the disk if you put the 
wrong disk or partition.  I recommend a shell script, fingers cannot be 
trusted.  You can also use "dd" but "cat" works.