something gives me the feeling i shouldn't have put root=/dev/hda1 or the problem is deeper than that..
If your trying to mount the 1st primary partition on your 1st ide drive as the 'root' partition ... then thats correct.
The panic message is refering to the kernel attempting to re-mount the root partition read/write so it can run /sbin/init, and failing at that point.
Check your /etc/fstab file !!!
When ever i/ve had that, it's just been either one of two possibles:
# a syntax error, ie /devhda1 rather than /dev/hda1
# a missing mount path
Grub is working fine, as it is finding the kernel and it's being loaded and going through preliminary initialisation. After the kernel reads the partition table to get its' own mappings it will already have the root partition mounted due to grub having passed the 'root=' cli string. But it will need to remount it read/write so that it can invoke 'init' and complete its' init process while being able to log.
Thats were it will attemp to read /etc/fstab !
If there is an error there, or it wasn't able to find a correct mapping due to an error in the partition table ... it will spit that message out and just freeze. It wont fall back on the path provided by the boot-loader.
Another install ?, or a liveCD boot, mount the problematic 'root', ... should fix it.
i think i put reiser in the kernel
, best to make sure. As you mention an 'initrd' there may have been facilities that existed in the previous setup that needed an initrd to load support modules/drivers. It wouldn't be to hard to overlook those on a rebuild
A little time traversing the configuration tree gui, comparing it to whats set in the previous config, is time well spent. If you have a previous config ".config", from the initial install and an initrd was being used, there would likely be a few key items that may be modular and so need to be preloaded, but maybe not. Again, that needs to be checked. If so, they will need to be configured as built ins. If the previous config isn't available, or you haven't got one at all, you will be looking at a full fresh configuration from scratch. That should at least occupy a couple of hours and is best spread out over a few sessions to get it right. Backing up the resulting config to use as a base for further updates is highly recomended. As a "make mrproper" will wipe out all the files prefixed with a "dot", remove it from the backup name first. The kernel defaults will probably be off target as per your own requirments so a good bit of time spent on that stage is necessary.
If the previous kernel is available for boot, you may find a copy of its' config in ...
/proc/config.gz , to use as a base.