[U-Boot] Beginners Questions on modding a NAS

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hi Jagan,

On Mon, 4 Mar 2013 23:02:58 +0530, Jagan Teki
<jagannadh.teki@gmail.com> wrote:

> Hi JPT,
> 
> On Mon, Mar 4, 2013 at 9:10 PM, JPT <j-p-t@gmx.net> wrote:
> > Hi,
> >
> > I've got a NAS which uses uboot:
> > U-Boot 1.1.4 (Feb  6 2012 - 14:40:46) Marvell version: 3.4.27
> >
> > It's a Netgear ReadyNAS Duo V2, and the original sofware sucks. ;)
> >
> > I would like to start with the original kernel (because it contains some
> > patches) and a custom debian made with multistrap.
> >
> > Where do I start?
> >
> > I'll add some information about the config.
> >
> > I believe these are the most important boot options.
> >
> > standalone=fsload 0x2000000 $(image_name);setenv bootargs $(console)
> > root=/dev/mtdblock0 rw ip=$(ipaddr):$(serverip)$(bootargs_end)
> > $(mvPhoneConfig); bootm 0x2000000;
> >
> > bootcmd=nand read.e 0x1200000 0x200000 0x600000;nand read.e 0x2000000
> > 0x800000 0x1000000;bootm 0x1200000 0x2000000
> >
> > bootargs=console=ttyS0,115200 reason=normal
> > mtdparts=nand_mtd:0x180000 at 0(u-boot),0x20000 at 0x180000(u-boot-env),0x600000 at 0x200000(uImage),0x1000000 at 0x800000(minirootfs),0x6800000 at 0x1800000(jffs2);
> >
> >
> > there are 5 mtds:
> > 1,5M mtd0 - ?
> > 128K mtd1 - ?
> > 6,0M mtd2 - kernel
> > 2,2M mtd3 - initrd (gzipped)
> >  89M mtd4 - jffs2 image, I think it contains a rescue image of the
> > filesystem which is applied to the harddisks.
> >
> > I dumped the kernel from mtd2, it is:
> > u-boot legacy uImage, Linux-2.6.31.8.duov2, Linux/ARM, OS Kernel Image (Not
> > compressed), 3442208 bytes, Tue Aug 28 05:21:43 2012, Load Address:
> > 0x00008000, Entry Point: 0x00008000, Header CRC: 0xDA1ECA31, Data CRC:
> > 0x269C27DE
> >
> >
> > I tried to load the kernel through tftp, but it crashed:
> >
> > Marvell>> dhcp
> >
> > BOOTP broadcast 1
> > *** Unhandled DHCP Option in OFFER/ACK: 28
> > *** Unhandled DHCP Option in OFFER/ACK: 28
> > DHCP client bound to address 192.168.20.35
> > Marvell>> set serverip 192.168.20.24
> >
> > Marvell>> tftpboot 0x02000000 /boot/kernel.img
> >
> > Using egiga0 device
> > TFTP from server 192.168.20.24; our IP address is 192.168.20.35
> > Filename '/boot/kernel.img'.
> > Load address: 0x2000000
> > Loading: #################################################################
> > ...
> > done
> > Bytes transferred = 3442272 (348660 hex)
> > Marvell>> go  0x02000000
> 
> Is this load address for kernel is correct? likely to have 8000 multiples..
> check it once.

Just about any address can be used to load and bootm (as
Michael notes) a kernel image. And 2000000 is a multiple of 8000, as we
are talking hex here. :)

> > ## Starting application at 0x02000000 ...
> > software interrupt
> > pc : [<0200001c>]          lr : [<00633cac>]
> > sp : 005fef68  ip : ffffffff     fp : 005ff7de
> > r10: 005ff3de  r9 : ffffe804     r8 : 005fffcc
> > r7 : 005ff388  r6 : 00000001     r5 : 005ff38c  r4 : 02000000
> > r3 : 30383101  r2 : f1012000     r1 : 005ff38c  r0 : c0c0e0c4
> > Flags: nZCv  IRQs off  FIQs off  Mode SVC_32
> > Resetting CPU ...
> 
> Try to debug the value from pc.
> Use the pc value using the instructions from doc/README.arm-unaligned-accesses

doc/README.unaligned-accesses is about data aborts, not SW interrupts.

> Thanks,
> Jagan.

Amicalement,
-- 
Albert.