New macro to fill a new process stack: in this way the stack is always aligned.

[bertos.git] / bertos / cpu / frame.h

diff --git a/bertos/cpu/frame.h b/bertos/cpu/frame.h
index 1a80fa1da21fa2faf415391212835573a99608ea..2244b3b1bf85a243ca1d1f407a365fd1bc99cf24 100644 (file)
--- a/bertos/cpu/frame.h
+++ b/bertos/cpu/frame.h
@@ -64,24 +64,37 @@
 
        /**
         * Initialization value for registers in stack frame.
-        * The register index is not directly corrispondent to CPU
-        * register numbers, but is related to how are pushed to
-        * stack (\see asm_switch_context).
-        * Index (CPU_SAVED_REGS_CNT - 1) is the CPSR register,
-        * the initial value is set to:
+        * For the CPSR register, the initial value is set to:
         * - All flags (N, Z, C, V) set to 0.
         * - IRQ and FIQ enabled.
         * - ARM state.
         * - CPU in Supervisor Mode (SVC).
         */
-       #define CPU_REG_INIT_VALUE(reg) \
-       ({  int a = 0; \
-               if(reg == 0) \
-                       a = (int)proc_exit; \
-               else if(reg == (CPU_SAVED_REGS_CNT - 1)) \
-                       a = 0x13; \
-               a; \
-       })
+       #define CPU_CREATE_NEW_STACK(stack, entry, exit) \
+       do { \
+               /* Process entry point */ \
+               CPU_PUSH_CALL_FRAME(stack, entry); \
+               /* LR (proc_exit) */ \
+               CPU_PUSH_CALL_FRAME(stack, exit); \
+               /* R11 */ \
+               CPU_PUSH_WORD(stack, 0x11111111); \
+               /* R10 */ \
+               CPU_PUSH_WORD(stack, 0x10101010); \
+               /* R9 */ \
+               CPU_PUSH_WORD(stack, 0x09090909); \
+               /* R8 */ \
+               CPU_PUSH_WORD(stack, 0x08080808); \
+               /* R7 */ \
+               CPU_PUSH_WORD(stack, 0x07070707); \
+               /* R6 */ \
+               CPU_PUSH_WORD(stack, 0x06060606); \
+               /* R5 */ \
+               CPU_PUSH_WORD(stack, 0x05050505); \
+               /* R4 */ \
+               CPU_PUSH_WORD(stack, 0x04040404); \
+               /* CPSR */ \
+               CPU_PUSH_WORD(stack, 0x00000013); \
+       } while (0)
 
 #elif CPU_PPC
 
@@ -244,4 +257,21 @@
        #endif /* !ARCH_EMUL */
 #endif /* !CPU_IDLE */
 
+/**
+ * Default macro for creating a new Process stack
+ */ 
+#ifndef CPU_CREATE_NEW_STACK
+
+       #define CPU_CREATE_NEW_STACK(stack, entry, exit) \
+               do { \
+                       size_t i; \
+                       /* Initialize process stack frame */ \
+                       CPU_PUSH_CALL_FRAME(stack, exit); \
+                       CPU_PUSH_CALL_FRAME(stack, entry); \
+                       /* Push a clean set of CPU registers for asm_switch_context() */ \
+                       for (i = 0; i < CPU_SAVED_REGS_CNT; i++) \
+                               CPU_PUSH_WORD(stack, CPU_REG_INIT_VALUE(i)); \
+               } while (0)
+#endif
+
 #endif /* CPU_ATTR_H */