As long as you get this error you miss HDD controller support.

Edit: Boot up with some good LiveCD, run lspci -v, write down all drivers in use, enable the very same drivers in your kernel, doesn't sound impossible, does it?

Edit 2: My first kernel build took 14 hrs, today's machines are not that slow, it takes less than 4 min now. Meaning start with lean kernel, disable all bells and whistles, ACPI and APM, things like that. And if you need help describe exactly to what point it boots, plus error messages.

Checklist:
1. HDD controller
2. MS partition table support
3. Root filesystem

This would suffice for IDE drives using PATA drivers.

With libata you need also SCSI and SCSI disk support.

These is the drivers I couldnt find in the kernel, perhaps someone could identify some of the drivers for me?
However, I suspect that the IDE controller is "Intel PIIXn" (according to gentoo forums) but I'm not sure. Also the PCI Bridge (i guess) is CONFIG_PCI, but also here, not sure (do you have to select a specific PCI bridge btw?) but the rest I have no clue about.
Also, I added support for all "normal" fs available (except like minix and the misc ones), but still not able to read the drive.
Any new suggestions? :S

lspic -v:
00:00.0 Host bridge: Intel Corporation 82820 820 (Camino) Chipset Host Bridge (MCH) (rev 03)
Subsystem: Intel Corporation 82820 820 (Camino) Chipset Host Bridge (MCH)
Flags: bus master, fast devsel, latency 0
Memory at e8000000 (32-bit, prefetchable) [size=64M]
Capabilities: [a0] AGP version 2.0

00:1e.0 PCI bridge: Intel Corporation 82801AA PCI Bridge (rev 02) (prog-if 00 [Normal decode])
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=02, subordinate=02, sec-latency=32
I/O behind bridge: 0000b000-0000cfff
Memory behind bridge: efc00000-efefffff
Prefetchable memory behind bridge: e5900000-e59fffff

00:1f.1 IDE interface: Intel Corporation 82801AA IDE Controller (rev 02) (prog-if 80 [Master])
Subsystem: Intel Corporation 82801AA IDE Controller
Flags: bus master, medium devsel, latency 0
I/O ports at ffa0 [size=16]

00:1f.3 SMBus: Intel Corporation 82801AA SMBus Controller (rev 02)
Subsystem: Intel Corporation 82801AA SMBus Controller
Flags: medium devsel
I/O ports at 0540 [size=16]

That's funny, my lspci output is different:
See that kernel driver line?
Try with lspci -vv or -vvv.
Intel Corporation 82801AA IDE Controller is your controller indeed, PIIX driver is probably the correct one. What's the PCI-ID of it? Where your boot stops now? Still the same error?

Yeah I see that now. According to gentoo portage I'm running 2.2.10.
However I cant find any modules/drivers in the very verbose version either. Maybe you got another mod of pciutils? Or maybe it just dont work, cause I tried -k aswell without result, just acts as a normal lspci. :s

This is the ouput i get from lspci -vvv:

00:00.0 Host bridge: Intel Corporation 82820 820 (Camino) Chipset Host Bridge (MCH) (rev 03)
Subsystem: Intel Corporation 82820 820 (Camino) Chipset Host Bridge (MCH)
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort+ >SERR- <PERR-
Latency: 0
Region 0: Memory at e8000000 (32-bit, prefetchable) [size=64M]
Capabilities: [a0] AGP version 2.0
Status: RQ=32 Iso- ArqSz=0 Cal=0 SBA+ ITACoh- GART64- HTrans- 64bit- FW- AGP3- Rate=x1,x2,x4
Command: RQ=1 ArqSz=0 Cal=0 SBA- AGP- GART64- 64bit- FW- Rate=<none>

00:1e.0 PCI bridge: Intel Corporation 82801AA PCI Bridge (rev 02) (prog-if 00 [Normal decode])
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B-
Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Latency: 0
Bus: primary=00, secondary=02, subordinate=02, sec-latency=32
I/O behind bridge: 0000b000-0000cfff
Memory behind bridge: efc00000-efefffff
Prefetchable memory behind bridge: e5900000-e59fffff
Secondary status: 66MHz- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort+ <SERR- <PERR-
BridgeCtl: Parity- SERR+ NoISA- VGA- MAbort- >Reset- FastB2B-

00:1f.1 IDE interface: Intel Corporation 82801AA IDE Controller (rev 02) (prog-if 80 [Master])
Subsystem: Intel Corporation 82801AA IDE Controller
Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Latency: 0
Region 4: I/O ports at ffa0 [size=16]

00:1f.3 SMBus: Intel Corporation 82801AA SMBus Controller (rev 02)
Subsystem: Intel Corporation 82801AA SMBus Controller
Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Interrupt: pin B routed to IRQ 0
Region 4: I/O ports at 0540 [size=16]


lspci -nn:
00:00.0 Host bridge [0600]: Intel Corporation 82820 820 (Camino) Chipset Host Bridge (MCH) [8086:2501] (rev 03)
00:1e.0 PCI bridge [0604]: Intel Corporation 82801AA PCI Bridge [8086:2418] (rev 02)
00:1f.1 IDE interface [0101]: Intel Corporation 82801AA IDE Controller [8086:2411] (rev 02)
00:1f.3 SMBus [0c05]: Intel Corporation 82801AA SMBus Controller [8086:2413] (rev 02)
This is the PCI_ID, right?

The boots stops at the very same place as before. Still same error. :/

OK, did you run lspci with -nv option as I suggested and checked it at http://kmuto.jp/debian/hcl/

Ok, now I've checked against the database (and finally i did find the 82801aa support unde I2C! ) but I still get the same error msg when I'm trying to boot.
I have to say that all the drivers wasnt name exact as they where in the database in the kernel but I added those that looked logic for the specific device, so I dont think I screw up there.

Might be wrong in my grub.conf anyway? :S

I2C?
Database tells 8086:2411 works with PIIX. You built in PIIX and still get "unknown-block(0,0)" message? grub.conf you posted earlier is correct.

I have support for BLK_DEV_PIIX and ATA_PIIX and still get the same error msg.

You have enabled both, not a good idea. Don't know, your HDD may be recognized as sda as a result, meaning the line root=/dev/hda3 in the grub.conf becomes wrong.

Edit: Remember, if you choose to use libata then you must enable SCSI and SCSI disk.

Finally! Thx alot
Removed the ATA_PIIX and it works fine now=)
Or well, not fine cause there was some other problem with the filesystem but atleast it boots now. The other is a different problem and I wont bother anymore. Once again, thx alot.

Great! You are welcome.