lib/armflush.c

   1 /* armflush.c - flush the instruction cache
   2
   3    __clear_cache is used in tccrun.c,  It is a built-in
   4    intrinsic with gcc.  However tcc in order to compile
   5    itself needs this function */
   6
   7 #ifdef __TINYC__
   8
   9 /* syscall wrapper */
  10 unsigned _tccsyscall(unsigned syscall_nr, ...);
  11
  12 /* arm-tcc supports only fake asm currently */
  13 __asm__(
  14     ".global _tccsyscall\n"
  15     "_tccsyscall:\n"
  16     "push    {r7, lr}\n\t"
  17     "mov     r7, r0\n\t"
  18     "mov     r0, r1\n\t"
  19     "mov     r1, r2\n\t"
  20     "mov     r2, r3\n\t"
  21     "svc     #0\n\t"
  22     "pop     {r7, pc}"
  23     );
  24
  25 /* from unistd.h: */
  26 #if defined(__thumb__) || defined(__ARM_EABI__)
  27 # define __NR_SYSCALL_BASE      0x0
  28 #else
  29 # define __NR_SYSCALL_BASE      0x900000
  30 #endif
  31 #define __ARM_NR_BASE           (__NR_SYSCALL_BASE+0x0f0000)
  32 #define __ARM_NR_cacheflush     (__ARM_NR_BASE+2)
  33
  34 #define syscall _tccsyscall
  35
  36 #else
  37
  38 #define _GNU_SOURCE
  39 #include <unistd.h>
  40 #include <sys/syscall.h>
  41 #include <stdio.h>
  42
  43 #endif
  44
  45 /* Flushing for tccrun */
  46 void __clear_cache(void *beginning, void *end)
  47 {
  48 /* __ARM_NR_cacheflush is kernel private and should not be used in user space.
  49  * However, there is no ARM asm parser in tcc so we use it for now */
  50     syscall(__ARM_NR_cacheflush, beginning, end, 0);
  51 }