arch/arm-native/kernel/syscall.c

   1 /*
   2     Copyright © 2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <inttypes.h>
   7 #include <aros/kernel.h>
   8 #include <aros/libcall.h>
   9
  10 #include <aros/arm/cpucontext.h>
  11
  12 #include <stddef.h>
  13 #include <string.h>
  14
  15 #include <proto/exec.h>
  16 #include <proto/kernel.h>
  17
  18 #include "kernel_cpu.h"
  19 #include "kernel_intern.h"
  20 #include "kernel_scheduler.h"
  21 #include "kernel_intr.h"
  22 #include "kernel_syscall.h"
  23
  24 extern char * __text_start;
  25 extern char * __text_end;
  26
  27 #ifndef _CUSTOM
  28 #define _CUSTOM NULL
  29 #endif
  30
  31 #define DREGS(x)
  32 #define D(x)
  33
  34 /*
  35     __vectorhand_swi:
  36
  37     this code currently assumes the caller is in user mode (and will break from any other mode)
  38
  39     r0 = passed to c handler, r1/r2 = temp
  40 */
  41 asm (
  42     ".globl __vectorhand_swi                   \n"
  43     ".type __vectorhand_swi,%function          \n"
  44     "__vectorhand_swi:                         \n"
  45     VECTCOMMON_START
  46     "           add     r1, r0, #13*4          \n" // store sp^ in ctx_sp
  47     "           stm     r1, {sp}^              \n"
  48     "           add     r1, r0, #14*4          \n" // store lr^ in ctx_lr
  49     "           stm     r1, {lr}^              \n"
  50     "           mov     fp, #0                 \n" // clear fp(??)
  51
  52     "           bl      handle_syscall         \n"
  53     VECTCOMMON_END
  54 );
  55
  56 void handle_syscall(void *regs)
  57 {
  58     register unsigned int addr;
  59     register unsigned int swi_no;
  60
  61     /* We determine the SWI number by reading in "tasks"
  62        program counter, subtract the instruction from it and
  63        obtain the value from there.  we also use this to check if
  64        we have been called from outwith the kernel's code (illegal!)
  65      */
  66
  67     addr = ((uint32_t *)regs)[15];
  68     addr -= 4;
  69     swi_no = *((unsigned int *)addr) & 0x00ffffff;
  70
  71     D(bug("[KRN] ## SWI %d @ 0x%p\n", swi_no, addr));
  72
  73     if (((char*)addr < &__text_start) || ((char*)addr >= &__text_end))
  74     {
  75         D(bug("[KRN] ## SWI : ILLEGAL ACCESS!\n"));
  76         return;
  77     }
  78     if (swi_no <= 0x0a || swi_no == 0x100)
  79     {
  80         DREGS(cpu_DumpRegs(regs));
  81
  82         switch (swi_no)
  83         {
  84             case SC_CLI:
  85             {
  86                 D(bug("[KRN] ## CLI...\n"));
  87                 ((uint32_t *)regs)[16] |= 0x80;
  88                 break;
  89             }
  90
  91             case SC_STI:
  92             {
  93                 D(bug("[KRN] ## STI...\n"));
  94                 ((uint32_t *)regs)[16] &= ~0x80;
  95                 break;
  96             }
  97
  98             case SC_SUPERSTATE:
  99             {
 100                 D(bug("[KRN] ## SUPERSTATE... (0x%p ->", ((uint32_t *)regs)[16]));
 101                 ((uint32_t *)regs)[16] &= ~CPUMODE_MASK;
 102                 ((uint32_t *)regs)[16] |= (0x80 | CPUMODE_SUPERVISOR);
 103                 D(bug(" 0x%p)\n", ((uint32_t *)regs)[16]));
 104                 break;
 105             }
 106
 107             case SC_ISSUPERSTATE:
 108             {
 109                 D(bug("[KRN] ## ISSUPERSTATE... "));
 110                 ((uint32_t *)regs)[0] = !(((((uint32_t *)regs)[16] & CPUMODE_MASK) == CPUMODE_USER) || ((((uint32_t *)regs)[16] & CPUMODE_MASK) == CPUMODE_SYSTEM));
 111                 D(bug("%d\n", ((uint32_t *)regs)[0]));
 112                 break;
 113             }
 114
 115             case SC_REBOOT:
 116             {
 117                 D(bug("[KRN] ## REBOOT...\n"));
 118                 asm volatile ("mov pc, #0\n"); // Jump to the reset vector..
 119                 break;
 120             }
 121             default:
 122                 core_SysCall(swi_no, regs);
 123                 break;
 124         }
 125     }
 126     else
 127     {
 128         D(bug("[KRN] ## SWI : ILLEGAL SWI!\n"));
 129         return;
 130     }
 131
 132     D(bug("[KRN] ## SWI returning ..\n"));
 133 }