Using ATA133 Hard Disks w/RAQ4 hardware and RAQ550 OS

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You can use ATA133 hard disks with the RAQ4 (with the RAQ550 os installed). Please note this requires downloading, editing, compiling and installing a new kernel so do this at your own risk! You should use the 2.9.36 rom only. It will allow you to boot from the rom if the kernel fails. Newer roms will not allow you to boot from rom so be careful. Also, this process will not allow you to use more than 127 GB of the disk regardless of how large it is. This is a limitation of using LBA48 disks with a LBA24 controller.

Download the source for the kernel from

The code is in the ide-disk.c:

static int probe_lba_addressing (ide_drive_t *drive, int arg) 


drive->addressing = 0; 

if (!(drive->id->cfs_enable_2 & 0x0400))
return -EIO; 

/* drive->addressing = arg; */ 

drive->addressing = 0; /* forced to LBA24 */ 

return 0; 


I just forced the value to return 0 regardless. This will prevent LBA48 hard drives from being detected as LBA48. In this case this is exactly what we want. They will be used as LBA24 drives even though they are LBA48 capable.

Then I followed the following steps to compile the kernel. This can take over an hour so be patient!

cd /usr/src/linux/ 
make dep 
make clean 
make boot 
make modules 
make modules_install 

cp vmlinux /boot/vmlinux-2.4.19C13_III 
gzip /boot/vmlinux-2.4.19C13_III 

cp vmlinux /boot/vmlinux-2.4.19C13_III 
bzip2 /boot/vmlinux-2.4.19C13_III 

cp /boot/ 

rm /boot/vmlinux.gz 
rm /boot/vmlinux.bz2 

ln -s /boot/vmlinux-2.4.19C13_III.gz /boot/vmlinux.gz 
ln -s /boot/vmlinux-2.4.19C13_III.bz2 /boot/vmlinux.bz2 

rm /boot/ 
ln -s /boot/ /boot/ 

chmod 755 /boot/ 

Note: The Cobalt RaQs cannot boot a BzImage kernel. However they can boot a GZip or BZip2 kernel. Also, replace 2.4.19C13_III with the correct revision for your kernel.

I created RPMs with these changes. You can download them from These files are provided without warranty or support.

--ChrisD 18:57, 15 May 2005 (UTC)

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