Kernel config for Transcend IDE Flash Module

Question

I'm trying to build a minimal custom kernel for my set-top-box (very limited ressources), which I use as home server.
From a recent Arch Live (USB-stick) the Transcend Flash SSD (4GB, 40pin IDE) gets detected as /dev/sda (by the "sd"-driver, I think). The Problem now is that I can't find the kernel settings and always get a kernel panic because it can't find the root device.
Here's the data I have:
lspci (Intel ICH chipset):
00:00.0 Host bridge: Intel Corporation 82830 830 Chipset Host Bridge (rev 04)
00:02.0 VGA compatible controller: Intel Corporation 82830 CGC [Chipset Graphics Controller] (rev 04)
00:02.1 Display controller: Intel Corporation 82830 CGC [Chipset Graphics Controller]
00:1d.0 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 02)
00:1d.7 USB Controller: Intel Corporation 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 82)
00:1f.0 ISA bridge: Intel Corporation 82801DB/DBL (ICH4/ICH4-L) LPC Interface Bridge (rev 02)
00:1f.1 IDE interface: Intel Corporation 82801DB (ICH4) IDE Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) SMBus Controller (rev 02)
00:1f.5 Multimedia audio controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Audio Controller (rev 02)
01:06.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
dmesg output from the live stick:
Linux version 2.6.30-ARCH (root@T-POWA-LX) (gcc version 4.4.1 (GCC) ) #1 SMP PREEMPT Fri Jul 31 18:10:38 UTC 2009
SCSI subsystem initialized
libata version 3.00 loaded.
ata_piix 0000:00:1f.1: version 2.13
ata_piix 0000:00:1f.1: enabling device (0005 -> 0007)
ata_piix 0000:00:1f.1: PCI INT A -> Link[LNKC] -> GSI 9 (level, low) -> IRQ 9
ata_piix 0000:00:1f.1: setting latency timer to 64
scsi0 : ata_piix
scsi1 : ata_piix
ata1: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0xffa0 irq 14
ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0xffa8 irq 15
ata1.00: CFA: TRANSCEND, 20071207, max UDMA/66
ata1.00: 7831152 sectors, multi 0: LBA
ata1.00: limited to UDMA/33 due to 40-wire cable
ata1.00: configured for UDMA/33
scsi 0:0:0:0: Direct-Access ATA TRANSCEND 2007 PQ: 0 ANSI: 5
ata2: port disabled. ignoring.
Driver 'sd' needs updating - please use bus_type methods
sd 0:0:0:0: [sda] 7831152 512-byte hardware sectors: (4.00 GB/3.73 GiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
sda: sda1 sda2 sda3
sd 0:0:0:0: [sda] Attached SCSI disk
sd 0:0:0:0: Attached scsi generic sg0 type 0
sd 2:0:0:0: Attached scsi generic sg1 type 0
ls -lh /dev/disk/by-id (the "USB_2.0_Memory_Adapter" is the live stick):
ata-TRANSCEND_20091118_500059E8 -> /dev/sda
ata-TRANSCEND_20091118_500059E8-part1 -> /dev/sda1
ata-TRANSCEND_20091118_500059E8-part2 -> /dev/sda2
ata-TRANSCEND_20091118_500059E8-part3 -> /dev/sda3
scsi-SATA_TRANSCEND_20091118_500059E8 -> /dev/sda
scsi-SATA_TRANSCEND_20091118_500059E8-part1 -> /dev/sda1
scsi-SATA_TRANSCEND_20091118_500059E8-part2 -> /dev/sda2
scsi-SATA_TRANSCEND_20091118_500059E8-part3 -> /dev/sda3
usb-USB_2.0_Memory_Adapter_AAAAA10062345-0:0 -> /dev/sdb
usb-USB_2.0_Memory_Adapter_AAAAA10062345-0:0-part1 -> /dev/sdb1
The kernel configuration I tried can be found here (from another box running Gentoo).
Any suggestions how I could find the right driver?
Thanks in advance,
lynix

Answer 1

Although I have compiled a custom kernel w/o any kind of automatic support, and it worked, I REALLY don' think that it is worth the effort.  In the wiki it recommends: zcat /proc/config.gz > .config  (from within the kernel directory), and I strongly recommend it as well.  All it does is copy some information from your existing kernel into your .config, which vastly improves your odds of having a working kernel right off the bat.  I would compile that, verify that it works, and from that point start taking out modules that you are confident have nothing to do with your system.  (don't forget to select your processor type, and deselect smp if you don't have smp)
I know that it is dissappointing and you'd like to perfect your kernel in one go, but I really think that in the long run, this is your best option.  I don't think that you are going to find anyone who is willing to take the time to tell you what options you personally need to compile in or as modules for you, however, there will be plenty of people who are willing to help. 
I know that there are even smarter solutions, including scripts that can supposedly configure a kernel based on the modules and options that are already loaded, but I think results are mixed.  Although, they might make a great starting point.  I think (but could be wrong) that gentoo's 'genkernel' worked like that.  Though I've used it years ago, I don't think that I fully understood how it worked at the time.
If you are dead set on minimizing all of the options that you compile for your kernel manually, your tools are lspci, lsmod, cat /proc* etc.  You can save the output, figure out what options correspond with that output, and hope for the best!
Good luck
Last edited by Convergence (2009-03-13 11:51:01)