I've been working on kexec into a kdump kernel on mips64 for work. Since kexec isn't supported by Cavium on the 2.3 SDK, I'm a bit on my own. Based on patches from Cavium, I can get the system to crash and boot into the kdump kernel, and come up to a shell on the console. However, gdb on /proc/vmcore basically doesn't work for me. One issue is that x/w on various kernel addresses doesn't work. I traced it to what looks like a bug in the kexec binary when it sets up the elf notes. The below patch seems to fix the issue, but I wonder why this has not been seen by others. I'm still using the kexec-tools-2.0.4 sources, but the is no difference between 2.0.4 and 2.0.5 in this file. 2.0.5 threw an error when trying to load the kernel and I haven't had time to debug that yet, so I've been proceeding with 2.0.4. Thanks, matthew diff -r -U8 --show-c-func /tmp/kexec-tools-2.0.4/kexec/arch/mips/crashdump-mips.h /home/sciadmin/workspace/ws_mdf_kdump/target/cavium/SDK/2.3/linux/embedded_rootfs/build/kexec-tools-2.0.4/kexec/arch/mips/crashdump-mips.h --- /tmp/kexec-tools-2.0.4/kexec/arch/mips/crashdump-mips.h 2011-10-02 15:56:38.000000000 -0700 +++ /home/sciadmin/workspace/ws_mdf_kdump/target/cavium/SDK/2.3/linux/embedded_rootfs/build/kexec-tools-2.0.4/kexec/arch/mips/crashdump-mips.h 2014-02-18 17:00:27.848982998 -0800 @@ -1,23 +1,23 @@ #ifndef CRASHDUMP_MIPS_H #define CRASHDUMP_MIPS_H struct kexec_info; int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline, unsigned long max_addr, unsigned long min_base); #ifdef __mips64 #define PAGE_OFFSET 0xa800000000000000ULL +#define MAXMEM 0 #else #define PAGE_OFFSET 0x80000000 +#define MAXMEM 0x80000000 #endif #define __pa(x) ((unsigned long)(X) & 0x7fffffff) -#define MAXMEM 0x80000000 - #define CRASH_MAX_MEMMAP_NR (KEXEC_MAX_SEGMENTS + 1) #define CRASH_MAX_MEMORY_RANGES (MAX_MEMORY_RANGES + 2) #define COMMAND_LINE_SIZE 512 /* Backup Region, First 1M of System RAM. */ #define BACKUP_SRC_START 0x00000000 #define BACKUP_SRC_END 0x000fffff
