Linux 2.6.32 PowerPC MTD partition mounted at boot

[Scott Wood]

On Wed, 2013-09-18 at 22:43 -0400, Dorin D wrote:
> I am working on bringing up two Linux systems, both based on Freescale
> PowerPC devices, one is a MPC8349, the other a P1020. I was able to
> build, install and boot the kernel on both cards. The kernel is 2.6.32
> and the  toolchains  are coming from the LTIBs packages from
> Freescale. 
> 
> Both cards have a 32 MByte NOR flash memory (AMD) boot flash. I have
> Uboot, kernel, RAM disk image and DTB in the boot flash and I want to
> use the spare space (about 20 MBytes) as flash file system. 
> 
> I have the following problem : the P1020 board boots fine using the
> RAM disk with the flash in the device tree , shows the flash device
> partitions (JFFS2) and DOESN"T try to mount a flash partition as root.
> The MPC8349 boots fine from the RAM disk but, after identifying the
> flash partitions, the kernel panics because is looking for a flash
> partition to mount as root partition and none of them is usable (not
> formatted). If I remove the flash from the device tree, the card boots
> fine using the RAM disk.
> 
> 
> I am not too familiar with Linux boot scripts and I didn't figure out
> where I can disable this tentative of mounting the MTD partition. I
> want the boards to boot and mount the RAM disk, as the P1020 board
> does. The flash partition will be initialized and mounted at a later
> time, but not as root partition.

Compare the kernel command line and kernel config for the two boards;
there's probably a relevant difference there (especially with the
"root=" parameter).

-Scott