On 16.01.2014, at 17:59, Thomas Falcon <tlfal...@linux.vnet.ibm.com> wrote:
> This patch allows registers to be properly read from and written to > when using the gdbstub to debug a ppc guest running in little > endian mode. It accomplishes this goal by byte swapping the values of > any registers if the MSR:LE value is set. > > Signed-off-by: Thomas Falcon<tlfal...@linux.vnet.ibm.com> > --- > Have created wrapper functions that swap mem_buf in-place. > mem_buf is swapped regardless of the the host's endianness if msr_le is true. > --- > target-ppc/cpu-qom.h | 2 ++ > target-ppc/gdbstub.c | 48 +++++++++++++++++++++++++++++++++++++++++++++ > target-ppc/translate_init.c | 4 ++-- > 3 files changed, 52 insertions(+), 2 deletions(-) > > diff --git a/target-ppc/cpu-qom.h b/target-ppc/cpu-qom.h > index 72b2232..992963f 100644 > --- a/target-ppc/cpu-qom.h > +++ b/target-ppc/cpu-qom.h > @@ -109,7 +109,9 @@ void ppc_cpu_dump_statistics(CPUState *cpu, FILE *f, > fprintf_function cpu_fprintf, int flags); > hwaddr ppc_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr); > int ppc_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg); > +int ppc_cpu_gdb_read_register_wrap(CPUState *cpu, uint8_t *buf, int reg); > int ppc_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg); > +int ppc_cpu_gdb_write_register_wrap(CPUState *cpu, uint8_t *buf, int reg); > int ppc64_cpu_write_elf64_qemunote(WriteCoreDumpFunction f, > CPUState *cpu, void *opaque); > int ppc64_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs, > diff --git a/target-ppc/gdbstub.c b/target-ppc/gdbstub.c > index 1c91090..964fd85 100644 > --- a/target-ppc/gdbstub.c > +++ b/target-ppc/gdbstub.c > @@ -21,6 +21,54 @@ > #include "qemu-common.h" > #include "exec/gdbstub.h" > > +/* The following functions are used to ensure the correct > + * transfer of registers between a little endian ppc target > + * and a big endian host by checking the LE bit in the Machine State Register > + */ > + > +int ppc_cpu_gdb_read_register_wrap(CPUState *cs, uint8_t *mem_buf, int n) > +{ > + PowerPCCPU *cpu = POWERPC_CPU(cs); > + CPUPPCState *env = &cpu->env; > + > + int len = ppc_cpu_gdb_read_register(cs, mem_buf, n),i; > + if(msr_le) > + { > + uint8_t tmp; > + for(i=0;i<len/2;i++) > + { > + tmp=*(mem_buf+i); > + *(mem_buf+i)=*(mem_buf+len-1-i); > + *(mem_buf+len-1-i)=tmp; > + } > + } > + return len; > +} > + > +int ppc_cpu_gdb_write_register_wrap(CPUState *cs, uint8_t *mem_buf, int n) > +{ > + PowerPCCPU *cpu = POWERPC_CPU(cs); > + CPUPPCState *env = &cpu->env; > + if(msr_le) > + { > + int len=0,i=0; > + if(n < 64) > + len=8; > + else if(n == 66) > + len=4; > + else > + len = sizeof(target_ulong); > + uint8_t tmp; > + for(i=0;i<len/2;i++) > + { > + tmp=*(mem_buf+i); > + *(mem_buf+i)=*(mem_buf+len-1-i); > + *(mem_buf+len-1-i)=tmp; > + } > + } > + return ppc_cpu_gdb_write_register(cs, mem_buf, n); Please run checkpatch.pl :). Also the return value is already then length. No need to duplicate that logic. Alex