Re: [Qemu-devel] [PATCH 1/3] linux-user:Support for MIPS64 user mode emulation in QEMU

[Andreas Färber]

This is about QEMU and linux-user is the user mode emulation, so please
change the subject to "linux-user: Add support for MIPS64" (note the
space that I reminded you of earlier, it looks weird without on Western
left-to-right screens).

Am 08.12.2011 06:25, schrieb address@hidden:
> From: Khansa Butt <address@hidden>
> 

As requested earlier, since this is a non-trivial change, please include
a summary here of what the patch does below. Should mention that people
can use it via "mips64-linux-user" and should describe syscall differences.

> 
> Signed-off-by: Khansa Butt <address@hidden>
> ---
>  configure                             |    1 +
>  default-configs/mips64-linux-user.mak |    1 +
>  linux-user/main.c                     |   21 +++++++++++++++++++--
>  linux-user/mips64/syscall.h           |    2 ++
>  4 files changed, 23 insertions(+), 2 deletions(-)
>  create mode 100644 default-configs/mips64-linux-user.mak
> 
> diff --git a/configure b/configure
> index ac4840d..e31229b 100755
> --- a/configure
> +++ b/configure
> @@ -914,6 +914,7 @@ m68k-linux-user \
>  microblaze-linux-user \
>  microblazeel-linux-user \
>  mips-linux-user \
> +mips64-linux-user \
>  mipsel-linux-user \

I would suggest to move your addition one line down, so that mips and
mipsel stay together.

For linux-user IIUC the ABI is relevant, so shouldn't this be
mipsn64-linux-user? We have a patch for mipsn32/mipsn32el. What about
mipsn64el?

>  ppc-linux-user \
>  ppc64-linux-user \
> diff --git a/default-configs/mips64-linux-user.mak 
> b/default-configs/mips64-linux-user.mak
> new file mode 100644
> index 0000000..1598bfc
> --- /dev/null
> +++ b/default-configs/mips64-linux-user.mak
> @@ -0,0 +1 @@
> +# Default configuration for mips64-linux-user

> diff --git a/linux-user/main.c b/linux-user/main.c
> index d1bbc57..17a74cd 100644
> --- a/linux-user/main.c
> +++ b/linux-user/main.c
> @@ -2157,7 +2157,8 @@ static int do_store_exclusive(CPUMIPSState *env)
>  void cpu_loop(CPUMIPSState *env)
>  {
>      target_siginfo_t info;
> -    int trapnr, ret;
> +    int trapnr;
> +    abi_long ret;
>      unsigned int syscall_num;
>  
>      for(;;) {
> @@ -2166,8 +2167,23 @@ void cpu_loop(CPUMIPSState *env)
>          cpu_exec_end(env);
>          switch(trapnr) {
>          case EXCP_SYSCALL:
> -            syscall_num = env->active_tc.gpr[2] - 4000;
>              env->active_tc.PC += 4;
> +#if defined(TARGET_MIPS64)

TARGET_ABI_MIPSN64?

> +            syscall_num = env->active_tc.gpr[2] - 5000;
> +            /* MIPS64 has eight argument registers so there is
> +             * no need to get arguments from stack
> +             */
> +            ret = do_syscall(env, env->active_tc.gpr[2],
> +                             env->active_tc.gpr[4],
> +                             env->active_tc.gpr[5],
> +                             env->active_tc.gpr[6],
> +                             env->active_tc.gpr[7],
> +                             env->active_tc.gpr[8],
> +                             env->active_tc.gpr[9],
> +                             env->active_tc.gpr[10],
> +                             env->active_tc.gpr[11]);
> +#else
> +            syscall_num = env->active_tc.gpr[2] - 4000;
>              if (syscall_num >= sizeof(mips_syscall_args)) {
>                  ret = -TARGET_ENOSYS;
>              } else {
> @@ -2205,6 +2221,7 @@ void cpu_loop(CPUMIPSState *env)
>                                   env->active_tc.gpr[7],
>                                   arg5, arg6, arg7, arg8);
>              }
> +#endif
>  done_syscall:
>              if (ret == -TARGET_QEMU_ESIGRETURN) {
>                  /* Returning from a successful sigreturn syscall.

> diff --git a/linux-user/mips64/syscall.h b/linux-user/mips64/syscall.h
> index 668a2b9..96f03da 100644
> --- a/linux-user/mips64/syscall.h
> +++ b/linux-user/mips64/syscall.h
> @@ -218,4 +218,6 @@ struct target_pt_regs {
>  
>  
>  
> +#define TARGET_QEMU_ESIGRETURN 255
> +
>  #define UNAME_MACHINE "mips64"

Andreas