altos: ARM ABI requires 8-byte aligned stack

[fw/altos] / src / kernel / ao_task.h

diff --git a/src/kernel/ao_task.h b/src/kernel/ao_task.h
index 709e10c60ce6f602a832a5b2396ee07390eeaaf1..03b629693c0e44baa9ba61a24caa39edc6d61ff4 100644 (file)
--- a/src/kernel/ao_task.h
+++ b/src/kernel/ao_task.h
@@ -26,10 +26,10 @@
 #define HAS_TASK_INFO 1
 #endif
 
-/* arm stacks must be 32-bit aligned */
+/* arm stacks must be 64-bit aligned */
 #ifndef AO_STACK_ALIGNMENT
 #ifdef __arm__
-#define AO_STACK_ALIGNMENT __attribute__ ((aligned(4)))
+#define AO_STACK_ALIGNMENT __attribute__ ((aligned(8)))
 #else
 #define AO_STACK_ALIGNMENT
 #endif
@@ -37,19 +37,24 @@
 
 /* An AltOS task */
 struct ao_task {
-       void *wchan;            /* current wait channel (NULL if running) */
+       void *wchan;                    /* current wait channel (NULL if running) */
        uint16_t alarm;                 /* abort ao_sleep time */
-       ao_arch_task_members            /* any architecture-specific fields */
-       uint8_t task_id;                /* unique id */
+       uint16_t task_id;               /* unique id */
+       /* Saved stack pointer */
+       union {
+               uint32_t        *sp32;
+               uint8_t         *sp8;
+       };
        const char *name;               /* task name */
-#ifdef NEWLIB
-       int __errno;                    /* storage for errno in newlib libc */
-#endif
 #if HAS_TASK_QUEUE
        struct ao_list  queue;
        struct ao_list  alarm_queue;
 #endif
-       uint8_t stack[AO_STACK_SIZE] AO_STACK_ALIGNMENT;        /* saved stack */
+       /* Provide both 32-bit and 8-bit stacks */
+       union {
+               uint32_t stack32[AO_STACK_SIZE>>2];
+               uint8_t stack8[AO_STACK_SIZE];
+       } AO_STACK_ALIGNMENT;
 #if HAS_SAMPLE_PROFILE
        uint32_t ticks;
        uint32_t yields;