The kernel updated its ABI to tell the relocatable kernel to run where it was loaded. We now need to set a flag in the kernel image. Since we only have the kernel image avialable as const data to kexec-tools c code, set the flag in the copy we put in purgatory, and have it set the flag in the kernel (after purgatory has run its checksum). To simplfy the purgatory code we can always copy the flag word back to the kernel as the c code made a copy of the original flag value. Signed-off-by: Milton Miller <miltonm at bga.com> --- v3: purgatory now copies the flag to the kernel master entrypoint instead of the kernel reading the value copied to 0 with the slave spinloop. rename the local varable to my_run_at_load to be more consistent, and change its type to uint32_t from unsigned int Index: kexec-tools/purgatory/arch/ppc64/v2wrap.S =================================================================== --- kexec-tools.orig/purgatory/arch/ppc64/v2wrap.S 2009-01-01 21:46:15.000000000 -0600 +++ kexec-tools/purgatory/arch/ppc64/v2wrap.S 2009-01-01 22:01:10.000000000 -0600 @@ -45,11 +45,14 @@ oris rn,rn,name##@h; \ ori rn,rn,name##@l -#define KDUMP_SIGNATURE 0xfeed1234 - .machine ppc64 .globl purgatory_start purgatory_start: b master + .org purgatory_start + 0x5c # ABI: possible run_at_load flag at 0x5c + .globl run_at_load +run_at_load: + .long 0 + .size run_at_load, . - run_at_load .org purgatory_start + 0x60 # ABI: slaves start at 60 with r3=phys slave: b $ .org purgatory_start + 0x100 # ABI: end of copied region @@ -57,7 +60,7 @@ slave: b $ # # The above 0x100 bytes at purgatory_start are replaced with the -# code from the kernel (or next stage) by kexec/arch/ppc64/kexec-ppc64.c +# code from the kernel (or next stage) by kexec/arch/ppc64/kexec-elf-ppc64.c # master: @@ -65,7 +68,6 @@ master: isync mr 17,3 # save cpu id to r17 mr 15,4 # save physical address in reg15 - mr 18,6 # save kdump flag in reg18 LOADADDR(6,my_toc) ld 2,0(6) #setup toc @@ -92,18 +94,13 @@ master: 80: LOADADDR(6,kernel) ld 4,0(6) # load the kernel address + LOADADDR(6,run_at_load) # the load flag + lwz 7,0(6) # possibly patched by kexec-elf-ppc64 + stw 7,0x5c(4) # and patch it into the kernel li 5,0 # r5 will be 0 for kernel mtctr 4 # prepare branch too mr 3,16 # restore dt address - LOADADDR(6,KDUMP_SIGNATURE) - cmpd 18,6 - bne regular - li 7,1 - std 7,24(4) # mark kdump flag at kernel -regular: - lwz 7,0(4) # get the first instruction that we stole - stw 7,0(0) # and put it in the slave loop at 0 # skip cache flush, do we care? bctr # start kernel Index: kexec-tools/kexec/arch/ppc64/crashdump-ppc64.h =================================================================== --- kexec-tools.orig/kexec/arch/ppc64/crashdump-ppc64.h 2009-01-01 21:46:15.000000000 -0600 +++ kexec-tools/kexec/arch/ppc64/crashdump-ppc64.h 2009-01-01 21:46:24.000000000 -0600 @@ -23,6 +23,8 @@ void add_usable_mem_rgns(unsigned long l #define _ALIGN_UP(addr,size) (((addr)+((size)-1))&(~((size)-1))) #define _ALIGN_DOWN(addr,size) ((addr)&(~((size)-1))) +#define KERNEL_RUN_AT_ZERO_MAGIC 0x72756e30 /* "run0" */ + extern uint64_t crash_base; extern uint64_t crash_size; extern unsigned int rtas_base; Index: kexec-tools/kexec/arch/ppc64/kexec-elf-ppc64.c =================================================================== --- kexec-tools.orig/kexec/arch/ppc64/kexec-elf-ppc64.c 2009-01-01 21:46:15.000000000 -0600 +++ kexec-tools/kexec/arch/ppc64/kexec-elf-ppc64.c 2009-01-01 21:46:24.000000000 -0600 @@ -92,6 +92,7 @@ int elf_ppc64_load(int argc, char **argv unsigned int my_panic_kernel; uint64_t my_stack, my_backup_start; uint64_t toc_addr; + uint32_t my_run_at_load; unsigned int slave_code[256/sizeof (unsigned int)], master_entry; #define OPT_APPEND (OPT_ARCH_MAX+0) @@ -307,6 +308,18 @@ int elf_ppc64_load(int argc, char **argv my_backup_start = info->backup_start; elf_rel_set_symbol(&info->rhdr, "backup_start", &my_backup_start, sizeof(my_backup_start)); + + /* Tell relocatable kernel to run at load address + * via word before slave code in purgatory + */ + + elf_rel_get_symbol(&info->rhdr, "run_at_load", &my_run_at_load, + sizeof(my_run_at_load)); + if (my_run_at_load == KERNEL_RUN_AT_ZERO_MAGIC) + my_run_at_load = 1; + /* else it should be a fixed offset image */ + elf_rel_set_symbol(&info->rhdr, "run_at_load", &my_run_at_load, + sizeof(my_run_at_load)); } /* Set stack address */ @@ -325,10 +338,13 @@ int elf_ppc64_load(int argc, char **argv my_backup_start = 0; my_stack = 0; toc_addr = 0; + my_run_at_load = 0; elf_rel_get_symbol(&info->rhdr, "kernel", &my_kernel, sizeof(my_kernel)); elf_rel_get_symbol(&info->rhdr, "dt_offset", &my_dt_offset, sizeof(my_dt_offset)); + elf_rel_get_symbol(&info->rhdr, "run_at_load", &my_run_at_load, + sizeof(my_run_at_load)); elf_rel_get_symbol(&info->rhdr, "panic_kernel", &my_panic_kernel, sizeof(my_panic_kernel)); elf_rel_get_symbol(&info->rhdr, "backup_start", &my_backup_start, @@ -341,6 +357,7 @@ int elf_ppc64_load(int argc, char **argv fprintf(stderr, "kernel is %llx\n", (unsigned long long)my_kernel); fprintf(stderr, "dt_offset is %llx\n", (unsigned long long)my_dt_offset); + fprintf(stderr, "run_at_load flag is %x\n", my_run_at_load); fprintf(stderr, "panic_kernel is %x\n", my_panic_kernel); fprintf(stderr, "backup_start is %llx\n", (unsigned long long)my_backup_start);
