Re: [Qemu-devel] arm return

[Max Filippov]

On Fri, Jun 1, 2012 at 3:57 PM, Davide Ferraretto
<address@hidden> wrote:
> I tried to insert " printf("exit\n"); ", but qemu dosen't write to monitor.

printf should not write to monitor (if you mean QEMU monitor), it
should go to stdout.
I don't have ARM compiler set up ATM, but x86_64 with the following
patch does what I describe:

$ git diff
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 20d2a74..ccb71dc 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -5052,6 +5052,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,

     switch(num) {
     case TARGET_NR_exit:
+        fprintf(stderr, "TARGET_NR_exit\n");
 #ifdef CONFIG_USE_NPTL
       /* In old applications this may be used to implement _exit(2).
          However in threaded applictions it is used for thread termination,
@@ -6833,6 +6834,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 #ifdef __NR_exit_group
         /* new thread calls */
     case TARGET_NR_exit_group:
+        fprintf(stderr, "TARGET_NR_exit_group\n");
 #ifdef TARGET_GPROF
         _mcleanup();
 #endif

$ cat a.c
#include <stdio.h>
int main()
{
    printf("Hello, world\n");
    return 0;
}

$ gcc -static a.c -o a
$ qemu-all/root/bin/qemu-x86_64 ./a
Hello, world
TARGET_NR_exit_group

> On 06/01/12 13:43, Max Filippov wrote:
>>
>> On Fri, Jun 1, 2012 at 3:16 PM, Davide Ferraretto
>> <address@hidden>  wrote:
>>>
>>> In arm user mode, where does qemu exit? Where is last qemu's instruction?
>>>
>>> I.E.
>>> int main (){return 0;}
>>> in what file does qemu run "return 0"??
>>
>> Simulated code reaches the point where libc calls 'exit' or 'exit_group'
>> syscall
>> and then QEMU goes to the do_syscall in the linux-user/syscall.c to
>> terminate
>> the process.
>>
>

-- 
Thanks.
-- Max