to solve the problem of the hardcoded command-line options i m using two trunks, one for the native image, and one for the kexec image.
i used the patch posted http://www.nabble.com/kexec-on-mips---a … 58033.html an included it by hand into both trunks. (i ll post some ready-to-use patches, as said, at weekend, or when its working^^)
now you should be able to execute the new kernel. to let it boot from an external device the commandline options must be changed in make kernel_menuconfig.
so far its working. now there is the problem to include support for your external device in the kernel. so i have added support for all things that could have something to do with usb.
all in all i have no luck getting my usb device recogniced. it also may be, that my device name /dev/sda2 is wrong.
Kernel command line: root=/dev/sda2 rootfstype=ext2 init=/etc/preinit noinitrd console=ttyS0,115200
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
PCI: Enabling device 0000:00:02.2 (0000 -> 0002)
PCI: Fixing up device 0000:00:02.2
ehci_hcd 0000:00:02.2: EHCI Host Controller
ehci_hcd 0000:00:02.2: new USB bus registered, assigned bus number 1
ehci_hcd 0000:00:02.2: irq 5, io mem 0x40002000
ehci_hcd 0000:00:02.2: USB 2.0 started, EHCI 1.00
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 4 ports detected
usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb1: Product: EHCI Host Controller
usb usb1: Manufacturer: Linux 2.6.28.7 ehci_hcd
usb usb1: SerialNumber: 0000:00:02.2
Initializing USB Mass Storage driver...
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
usbcore: registered new interface driver libusual
usbcore: registered new interface driver usbhid
usbhid: v2.6:USB HID core driver
TCP vegas registered
NET: Registered protocol family 17
802.1Q VLAN Support v1.8 Ben Greear <greearb@candelatech.com>
All bugs added by David S. Miller <davem@redhat.com>
VFS: Cannot open root device "sda2" or unknown-block(0,0)
Please append a correct "root=" boot option; here are the available partitions:
1f00 256 mtdblock0 (driver?)
1f01 3776 mtdblock1 (driver?)
1f02 3002 mtdblock2 (driver?)
1f03 960 mtdblock3 (driver?)
1f04 64 mtdblock4 (driver?)
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
i hope, this will help someone.
(Last edited by wurststulle on 25 Feb 2009, 17:13)