I can't get kernel 2.6.15 boot properly. Here's what it prints out on screen on startup:

kernel-panic:udf-fs: no partition found not syncing: vfs unable to mount root fs on unknown block (3,1)

I've compiled ext2,ext3 and reiserfs as "built-in" as well as IDE support.

I don't have SATA disks.

Here's some important files:

/etc/lilo.conf

# LILO configuration file
# generated by 'liloconfig'
#
# Start LILO global section
boot = /dev/hda
message = /boot/boot_message.txt
prompt
timeout = 1200
# Override dangerous defaults that rewrite the partition table:
change-rules
reset
# VESA framebuffer console @ 1024x768x256
vga = 773
# Normal VGA console
# vga = normal
# VESA framebuffer console @ 1024x768x64k
# vga=791
# VESA framebuffer console @ 1024x768x32k
# vga=790
# VESA framebuffer console @ 1024x768x256
# vga=773
# VESA framebuffer console @ 800x600x64k
# vga=788
# VESA framebuffer console @ 800x600x32k
# vga=787
# VESA framebuffer console @ 800x600x256
# vga=771
# VESA framebuffer console @ 640x480x64k
# vga=785
# VESA framebuffer console @ 640x480x32k
# vga=784
# VESA framebuffer console @ 640x480x256
# vga=769
# End LILO global section
# Windows bootable partition config begins
other = /dev/hdb1
label = Windows
table = /dev/hdb
# Windows bootable partition config ends
# Linux bootable partition config begins
image = /boot/vmlinuz
root = /dev/hda1
label = Linux
read-only
# Linux bootable partition config ends

--------
/etc/fstab
--------

/dev/hda2 swap swap defaults 0 0
/dev/hda1 / reiserfs defaults 1 1
/dev/hdb1 /windows ntfs ro 1 0
/dev/cdrom /mnt/cdrom auto noauto,owner,ro 0 0
/dev/fd0 /mnt/floppy auto noauto,owner 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
proc /proc proc defaults 0 0

My ide controller:
00:1f.1 IDE interface: Intel Corporation 82801BA IDE U100 (rev 12)

PIIxn-something is the only option related to intel ide controller into config process:
CONFIG_BLK_DEV_PIIX=y

I'm out of ideas... I don't know what else I could try

*Note:

I built kernel "from scratch" without doing "make oldconfig"

you must have
in partition section
unix
and you have windows so you need
Windows Volume



in file systems you need
ufs and vfs


you need
initrd
where it is general?

You mean in /etc/fstab or /etc/lilo.conf ?

Do you suggest I should compile udf or vfs support ?

no you need to run

make menuconfig again
and recompile wioth the above things included.

and make 100% certain you chose the correct IDE controller.