Thumb syscalls

PATCH New Paul Brook 1 participant 1 message Apr 26, 2005

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Paul Brook

author

2005-04-26 22:50 UTC #0 lore raw

PATCH 1/1 Thumb syscalls

The attached patch implements syscalls when in thumb mode.

Paul

Index: linux-user/main.c
===================================================================
RCS file: /cvsroot/qemu/qemu/linux-user/main.c,v
retrieving revision 1.65

main.c +15 -4

diff -u -p -r1.65 main.c
@@ -359,16 +359,27 @@ void cpu_loop(CPUARMState *env)
         case EXCP_SWI:
             {
                 /* system call */
-                insn = ldl((void *)(env->regs[15] - 4));
-                n = insn & 0xffffff;
+                if (env->thumb) {
+                    insn = lduw((void *)(env->regs[15] - 2));
+                    n = insn & 0xff;
+                } else {
+                    insn = ldl((void *)(env->regs[15] - 4));
+                    n = insn & 0xffffff;
+                }
+
                 if (n == ARM_NR_cacheflush) {
                     arm_cache_flush(env->regs[0], env->regs[1]);
                 } else if (n == ARM_NR_semihosting
                            || n == ARM_NR_thumb_semihosting) {
                     env->regs[0] = do_arm_semihosting (env);
-                } else if (n >= ARM_SYSCALL_BASE) {
+                } else if (n >= ARM_SYSCALL_BASE
+                           || (env->thumb && n == ARM_THUMB_SYSCALL)) {
                     /* linux syscall */
-                    n -= ARM_SYSCALL_BASE;
+                    if (env->thumb) {
+                        n = env->regs[7];
+                    } else {
+                        n -= ARM_SYSCALL_BASE;
+                    }
                     env->regs[0] = do_syscall(env, 
                                               n, 
                                               env->regs[0],

Index: linux-user/arm/syscall.h
===================================================================
RCS file: /cvsroot/qemu/qemu/linux-user/arm/syscall.h,v retrieving revision 1.5

arm/syscall.h +1 -0

diff -u -p -r1.5 syscall.h
@@ -26,6 +26,7 @@ struct target_pt_regs {
 #define ARM_ORIG_r0	uregs[17]
 
 #define ARM_SYSCALL_BASE	0x900000
+#define ARM_THUMB_SYSCALL	0
 
 #define ARM_NR_cacheflush (ARM_SYSCALL_BASE + 0xf0000 + 2)