enable kdump capture kernel functionality

[Cosmin Banu]

Hi,

I am trying to rebuild the kernel for one of our powerpc devices to include kdump capture kernel functionality, but I'm having trouble getting it to load for use on panic.
I'm running Linux 3.14.60 on e500v2 (COMX-P2020 module).

I've tried following the documentation at https://www.kernel.org/doc/Documentation/kdump/kdump.txt:
CONFIG_KEXEC=y
CONFIG_CRASH_DUMP=y
CONFIG_NONSTATIC_KERNEL=y
CONFIG_PROC_VMCORE=y
CONFIG_RELOCATABLE=y
CONFIG_RELOCATABLE_PPC32=y

These are the parameters I'm using to boot the kernel:
> cat /proc/cmdline
root=/dev/mmcblk0p2 rw rootdelay=15 ip=10.215.181.92::10.215.180.1:255.255.254.0:XSTREAM-DEV2:eth0 loglevel=0 mfgstring=1:XF40-LB-SSSSSS-MMDDYY console=ttyS0,115200 ramdisk_size=700000 cache-sram-size=0x10000 crashkernel=0x04000000 at 0x04000000 slub_debug=FPZ

Running the following command:
> kexec -l /boot/uImage -t uImage-ppc --dtb=/boot/comx.dtb --initrd=/boot/initramfs_data.cpio --command-line="root=/dev/mmcblk0p2 3 maxcpus=1 irqpoll noirqdistrib reset_devices rw rootdelay=15 ip=10.215.181.92::10.215.180.1:255.255.254.0:XSTREAM-DEV2:eth0 loglevel=0 mfgstring=1:XF40-LB-SSSSSS-MMDDYY console=ttyS0,115200 ramdisk_size=700000 cache-sram-size=0x10000"
Returns:
Can't add kernel to addr 0x00000000 len 0
Cannot load /boot/uImage

I'm not sure what mechanism is used to load the kernel and where this can be configured. I assumed that the crashkernel parameter from the cmdline is the actual setting.
Where should I set this value? Also, how can I ensure that the two kernel images don't overlap?

Thanks in advance,
Cosmin