Re: [Qemu-devel] Debian 7.8.0 SPARC64 on qemu - anything i can do to speedup the emulation?

[Dennis Luehring <dl.soluz@gmx.net>]

Am 29.07.2015 um 14:34 schrieb Karel Gardas:
>   Once it boots, tell me how to find the asnwers to your
> questions.

compile with gcc test.cpp and run

-----------
#include <stdint.h>
#include <stdio.h>
#include <stddef.h>
#include <string.h>
#include <assert.h>

int main()
{
   uint16_t value = 0x1234;

   {
     volatile uint8_t* ptr = (uint8_t*)&value;
     printf("endianess: %s\n", ptr[0]==0x34 ? "little":"big");
   }

   uint8_t buffer[1+sizeof(value)]={0};
   uint8_t* ptr = buffer;
   if(ptrdiff_t(ptr) % 2 == 0)
   {
     ++ptr;
   }
   uint16_t* unaligned_word = (uint16_t*)ptr;

   ::memcpy(unaligned_word, &value, sizeof(value));

   printf("try to access unaligned word\n");
   uint16_t read = *unaligned_word; // here can happen Bus-Errors, 
Exceptions, whatever your architecture likes
   printf("  equal to 0x%04X: %s\n", value, read == value ? 
"YES":"!!NO!!"); // sometimes you get the value - but its still wrong
   printf("  value: 0x%04X\n", read);
   printf("done\n");

   return 0;
}
-----------