Hi, I am seeing a problem with the kdump kernel running on my Freescale mpc8536 based board. Specifically when the crash kernel boots after a forced panic, vmcore fails to initialize. The following errors are displayed by vmcore_init() Warning: Core image elf header not found Kdump: vmcore not initialized I only see this problem when loading a uImage-ppc image type. The problem does not occur when loading a elf-ppc image type (i.e. vmlinux). I am using kernel version 2.6.39 and kexec-tools version as of 6/16/2011. The problem seems to one of vmcore_init not being able to locate the ELF image header within the old kernel (/dev/oldmem). See additional details below. Reserved crash kernel memory: crashkernel=256M at 512 uImage file built as below to match the reserved memory area: lxapp-2:lc$ mkimage -A ppc -O linux -T kernel -C gzip -a 0x20000000 -e 0x20000000 -n Linux-2.6.39.3-495-g56d1401-dirty -d vmlinux.bin.gz uImage.kdump Image Name: Linux-2.6.39.3-495-g56d1401-dirt Created: Mon Sep 12 14:06:23 2011 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 4842545 Bytes = 4729.05 kB = 4.62 MB Load Address: 20000000 Entry Point: 20000000 After loading the crash kernel (uImage.kdump) I then force a kernel panic and the crash kernel is invoked as expected. However it appears as though the crash kernel is having trouble accessing some of the memory of the original kernel (/dev/oldmem). Specifically the test for the ELF header magic number is failing during vmcore_init(). As a result /proc/vmcore is not available within the crash kernel and hence I cannot create a dump of the original kernel. Here's the errors I am seeing. Note I have augmented the debug prints slightly to verify the inability to see the kernel image elf header. Reading 16 bytes from address 0x000000002086E000 within /dev/oldmem 00 00 00 00 00 00 00 00 Warning: Core image elf header not found Kdump: vmcore not initialized Here's the crash kernel bootline showing the elfcorehdr argument passed to the crash kernel. Kernel command line: irqpoll maxcpus=1 reset_devices boot_mode=crash root=/dev/nfs nfsroot=127.3.252.1:/var/export/hitchhiker-6kn/current/rootfs ip=127.3.10.1:127.3.252.1:127.3.252.1:255.255.0.0:hitchhiker-6kn:eth0:off rbn_net_dev=eth0 console=ttyS0,115200 dump_type=kernel dump_server=0.0.0.0 dump_server_port=9999 hwether=x board_name=wolf_lc slot_number=255 elfcorehdr=532920K savemaxmem=2048M To help me debug all of this I added some debug prints to the powerpc kexec code (default_machine_kexec()) so I could verify the kernel kimage and memory segment contents. See below. Bye! Calling reboot_code_buffer (vaddr:0xe086f000): page_list=0x00000004, reboot_code_buffer_phys=0x2086f000, start=0x2fffa724 Dumping kimage @ 0xdfbdf800 head: 0x00000004 entry: 0xdfbdf800 last_entry: 0xdfbdf800 destination: 0x00000000 start: 0x2fffa724 control_code_page: 0xc0c97de0 swap_page: 0x (null) control_page: 0x2086ffff type: 0x00000001 preserve_context: 0x00000000 nr_segments = 5 segment[0].buf = 48831008 segment[0].bufsz = 75d640 segment[0].mem = 0x20000000 segment[0].memsz = 85e000 segment[1].buf = 1007d988 segment[1].bufsz = 10000 segment[1].mem = 0x2085e000 segment[1].memsz = 10000 segment[2].buf = 1007d350 segment[2].bufsz = 400 segment[2].mem = 0x2086e000 segment[2].memsz = 1000 segment[3].buf = 10093fa8 segment[3].bufsz = 2b62 segment[3].mem = 0x217fd000 segment[3].memsz = 3000 segment[4].buf = 1008e380 segment[4].bufsz = 5c20 segment[4].mem = 0x2fffa000 segment[4].memsz = 6000 Thanks for any help, Dennis
