mini-os: initial ARM support

index ea409f4..27e3c56 100644
@@ -69,6 +69,8 @@ void setup_xen_features(void)
 __attribute__((weak)) void app_shutdown(unsigned reason)
 {
     printk("Shutdown requested: %d\n", reason);
+    struct sched_shutdown sched_shutdown = { .reason = reason };
+    HYPERVISOR_sched_op(SCHEDOP_shutdown, &sched_shutdown);
 }
 
 static void shutdown_thread(void *p)

@@ -76,12 +78,14 @@ static void shutdown_thread(void *p)
     const char *path = "control/shutdown";
     const char *token = path;
     xenbus_event_queue events = NULL;
-    char *shutdown, *err;
+    char *shutdown = NULL, *err;
     unsigned int shutdown_reason;
     xenbus_watch_path_token(XBT_NIL, path, token, &events);
-    while ((err = xenbus_read(XBT_NIL, path, &shutdown)) != NULL)
+    while ((err = xenbus_read(XBT_NIL, path, &shutdown)) != NULL || !strcmp(shutdown, ""))
     {
         free(err);
+        free(shutdown);
+        shutdown = NULL;
         xenbus_wait_for_watch(&events);
     }
     err = xenbus_unwatch_path_token(XBT_NIL, path, token);

@@ -106,7 +110,7 @@ static void shutdown_thread(void *p)
 /* This should be overridden by the application we are linked against. */
 __attribute__((weak)) int app_main(start_info_t *si)
 {
-    printk("Dummy main: start_info=%p\n", si);
+    printk("kernel.c: dummy main: start_info=%p\n", si);
     return 0;
 }
 

index 73eb6fb..aec0586 100644
@@ -185,7 +185,7 @@ void _exit(int ret)
 
 int app_main(start_info_t *si)
 {
-    printk("Dummy main: start_info=%p\n", si);
+    printk("main.c: dummy main: start_info=%p\n", si);
     main_thread = create_thread("main", call_main, si);
     return 0;
 }

index 89bc382..2c8d033 100644
@@ -212,7 +212,7 @@ void block_domain(s_time_t until)
 
 
 /*
- * Just a dummy 
+ * Just a dummy
  */
 static void timer_handler(evtchn_port_t ev, struct pt_regs *regs, void *ign)
 {

index 380f53c..5538bd4 100644
@@ -124,7 +124,7 @@ void print(int direct, const char *fmt, va_list args)
     static char   buf[1024];
     
     (void)vsnprintf(buf, sizeof(buf), fmt, args);
- 
+
     if(direct)
     {
         (void)HYPERVISOR_console_io(CONSOLEIO_write, strlen(buf), buf);

index 036b84b..2da9b01 100644
@@ -138,7 +138,8 @@ evtchn_port_t bind_virq(uint32_t virq, evtchn_handler_t handler, void *data)
 	op.virq = virq;
 	op.vcpu = smp_processor_id();
 
-	if ( (rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, &op)) != 0 )
+	rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, &op);
+	if (rc != 0)
 	{
 		printk("Failed to bind virtual IRQ %d with rc=%d\n", virq, rc);
 		return -1;

index 22ed450..f6ab3ad 100644
@@ -38,6 +38,15 @@
 #include <inttypes.h>
 #include <mini-os/gntmap.h>
 
+//#define GNTMAP_DEBUG
+#ifdef GNTMAP_DEBUG
+#define DEBUG(_f, _a...) \
+    printk("MINI_OS(gntmap.c:%d): %s" _f "\n", __LINE__, __func__, ## _a)
+#else
+#define DEBUG(_f, _a...)    ((void)0)
+#endif
+
+
 #define DEFAULT_MAX_GRANTS 128
 
 struct gntmap_entry {

@@ -61,10 +70,8 @@ gntmap_find_free_entry(struct gntmap *map)
             return &map->entries[i];
     }
 
-#ifdef GNTMAP_DEBUG
-    printk("gntmap_find_free_entry(map=%p): all %d entries full\n",
+    DEBUG("(map=%p): all %d entries full",
            map, map->nentries);
-#endif
     return NULL;
 }
 

@@ -83,9 +90,7 @@ gntmap_find_entry(struct gntmap *map, unsigned long addr)
 int
 gntmap_set_max_grants(struct gntmap *map, int count)
 {
-#ifdef GNTMAP_DEBUG
-    printk("gntmap_set_max_grants(map=%p, count=%d)\n", map, count);
-#endif
+    DEBUG("(map=%p, count=%d)", map, count);
 
     if (map->nentries != 0)
         return -EBUSY;

@@ -157,10 +162,8 @@ gntmap_munmap(struct gntmap *map, unsigned long start_address, int count)
     int i, rc;
     struct gntmap_entry *ent;
 
-#ifdef GNTMAP_DEBUG
-    printk("gntmap_munmap(map=%p, start_address=%lx, count=%d)\n",
+    DEBUG("(map=%p, start_address=%lx, count=%d)",
            map, start_address, count);
-#endif
 
     for (i = 0; i < count; i++) {
         ent = gntmap_find_entry(map, start_address + PAGE_SIZE * i);

@@ -189,14 +192,12 @@ gntmap_map_grant_refs(struct gntmap *map,
     struct gntmap_entry *ent;
     int i;
 
-#ifdef GNTMAP_DEBUG
-    printk("gntmap_map_grant_refs(map=%p, count=%" PRIu32 ", "
+    DEBUG("(map=%p, count=%" PRIu32 ", "
            "domids=%p [%" PRIu32 "...], domids_stride=%d, "
-           "refs=%p [%" PRIu32 "...], writable=%d)\n",
+           "refs=%p [%" PRIu32 "...], writable=%d)",
            map, count,
            domids, domids == NULL ? 0 : domids[0], domids_stride,
            refs, refs == NULL ? 0 : refs[0], writable);
-#endif
 
     (void) gntmap_set_max_grants(map, DEFAULT_MAX_GRANTS);
 

@@ -224,9 +225,7 @@ gntmap_map_grant_refs(struct gntmap *map,
 void
 gntmap_init(struct gntmap *map)
 {
-#ifdef GNTMAP_DEBUG
-    printk("gntmap_init(map=%p)\n", map);
-#endif
+    DEBUG("(map=%p)", map);
     map->nentries = 0;
     map->entries = NULL;
 }

@@ -237,9 +236,7 @@ gntmap_fini(struct gntmap *map)
     struct gntmap_entry *ent;
     int i;
 
-#ifdef GNTMAP_DEBUG
-    printk("gntmap_fini(map=%p)\n", map);
-#endif
+    DEBUG("(map=%p)", map);
 
     for (i = 0; i < map->nentries; i++) {
         ent = &map->entries[i];

index c08b6f1..59f7b63 100644
@@ -61,7 +61,7 @@
 
 static inline void _raw_spin_unlock(spinlock_t *lock)
 {
-	char oldval = 1;
+	char oldval = ARCH_SPIN_LOCK_UNLOCKED;
 	__asm__ __volatile__(
 		spin_unlock_string
 	);

index 5ac5c1c..174945e 100644
@@ -85,6 +85,7 @@ void schedule(void)
         printk("Must not call schedule() from a callback\n");
         BUG();
     }
+
     if (flags) {
         printk("Must not call schedule() with IRQs disabled\n");
         BUG();

@@ -188,6 +189,8 @@ struct _reent *__getreent(void)
 	}
     }
 #endif
+#else
+#error Not implemented yet
 #endif
     return _reent;
 }

index c5d9b02..934f23b 100644
@@ -276,7 +276,7 @@ static void xenbus_evtchn_handler(evtchn_port_t port, struct pt_regs *regs,
 }
 
 static int nr_live_reqs;
-static spinlock_t req_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(req_lock);
 static DECLARE_WAIT_QUEUE_HEAD(req_wq);
 
 /* Release a xenbus identifier */

new file mode 100644
index 0000000..e420a98
@@ -0,0 +1,31 @@
+#include <mini-os/os.h>
+#include <mini-os/mm.h>
+#include <mini-os/events.h>
+
+#if defined(__x86_64__)
+char irqstack[2 * STACK_SIZE];
+
+static struct pda
+{
+    int irqcount;       /* offset 0 (used in x86_64.S) */
+    char *irqstackptr;  /*        8 */
+} cpu0_pda;
+#endif
+
+void arch_init_events(void)
+{
+#if defined(__x86_64__)
+    asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0));
+    wrmsrl(0xc0000101, &cpu0_pda); /* 0xc0000101 is MSR_GS_BASE */
+    cpu0_pda.irqcount = -1;
+    cpu0_pda.irqstackptr = (void*) (((unsigned long)irqstack + 2 * STACK_SIZE)
+                                    & ~(STACK_SIZE - 1));
+#endif
+}
+
+void arch_fini_events(void)
+{
+#if defined(__x86_64__)
+    wrmsrl(0xc0000101, NULL); /* 0xc0000101 is MSR_GS_BASE */
+#endif
+}

index 2da9b01..d60630b 100644
@@ -167,44 +167,28 @@ evtchn_port_t bind_pirq(uint32_t pirq, int will_share,
 	return op.port;
 }
 
-#if defined(__x86_64__)
-char irqstack[2 * STACK_SIZE];
-
-static struct pda
-{
-    int irqcount;       /* offset 0 (used in x86_64.S) */
-    char *irqstackptr;  /*        8 */
-} cpu0_pda;
-#endif
-
 /*
  * Initially all events are without a handler and disabled
  */
 void init_events(void)
 {
     int i;
-#if defined(__x86_64__)
-    asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0));
-    wrmsrl(0xc0000101, &cpu0_pda); /* 0xc0000101 is MSR_GS_BASE */
-    cpu0_pda.irqcount = -1;
-    cpu0_pda.irqstackptr = (void*) (((unsigned long)irqstack + 2 * STACK_SIZE)
-                                    & ~(STACK_SIZE - 1));
-#endif
+
     /* initialize event handler */
     for ( i = 0; i < NR_EVS; i++ )
 	{
         ev_actions[i].handler = default_handler;
         mask_evtchn(i);
     }
+
+    arch_init_events();
 }
 
 void fini_events(void)
 {
     /* Dealloc all events */
     unbind_all_ports();
-#if defined(__x86_64__)
-    wrmsrl(0xc0000101, NULL); /* 0xc0000101 is MSR_GS_BASE */
-#endif
+    arch_fini_events();
 }
 
 void default_handler(evtchn_port_t port, struct pt_regs *regs, void *ignore)

index 0e9d3a7..0452d21 100644
@@ -25,6 +25,9 @@
 typedef void (*evtchn_handler_t)(evtchn_port_t, struct pt_regs *, void *);
 
 /* prototypes */
+void arch_init_events(void);
+void arch_fini_events(void);
+
 int do_event(evtchn_port_t port, struct pt_regs *regs);
 evtchn_port_t bind_virq(uint32_t virq, evtchn_handler_t handler, void *data);
 evtchn_port_t bind_pirq(uint32_t pirq, int will_share, evtchn_handler_t handler, void *data);

index 54046d3..58ede15 100644
@@ -28,6 +28,7 @@
 
 #include <mini-os/os.h>
 #include <mini-os/lib.h> /* for printk, memcpy */
+#include <xen/xen.h>
 
 /*
  * Shared page for communicating with the hypervisor.

@@ -87,14 +88,40 @@ static inline void sse_init(void) {
 #define sse_init()
 #endif
 
+
+void start_kernel(void);
+
+/*
+ * INITIAL C ENTRY POINT.
+ */
 void
 arch_init(start_info_t *si)
 {
+	static char hello[] = "Bootstrapping...\n";
+
+	(void)HYPERVISOR_console_io(CONSOLEIO_write, strlen(hello), hello);
+
+	trap_init();
+
+	/* print out some useful information  */
+	printk("Xen Minimal OS!\n");
+	printk("  start_info: %p(VA)\n", si);
+	printk("    nr_pages: 0x%lx\n", si->nr_pages);
+	printk("  shared_inf: 0x%08lx(MA)\n", si->shared_info);
+	printk("     pt_base: %p(VA)\n", (void *)si->pt_base);
+	printk("nr_pt_frames: 0x%lx\n", si->nr_pt_frames);
+	printk("    mfn_list: %p(VA)\n", (void *)si->mfn_list);
+	printk("   mod_start: 0x%lx(VA)\n", si->mod_start);
+	printk("     mod_len: %lu\n", si->mod_len);
+	printk("       flags: 0x%x\n", (unsigned int)si->flags);
+	printk("    cmd_line: %s\n",
+			si->cmd_line ? (const char *)si->cmd_line : "NULL");
+
 	/*Initialize floating point unit */
-        fpu_init();
+	fpu_init();
 
-        /* Initialize SSE */
-        sse_init();
+	/* Initialize SSE */
+	sse_init();
 
 	/* Copy the start_info struct to a globally-accessible area. */
 	/* WARN: don't do printk before here, it uses information from

@@ -118,12 +145,15 @@ arch_init(start_info_t *si)
 		(unsigned long)failsafe_callback, 0);
 #endif
 
-
+	start_kernel();
 }
 
 void
 arch_fini(void)
 {
+	/* Reset traps */
+	trap_fini();
+
 #ifdef __i386__
 	HYPERVISOR_set_callbacks(0, 0, 0, 0);
 #else

@@ -132,9 +162,7 @@ arch_fini(void)
 }
 
 void
-arch_print_info(void)
+arch_do_exit(void)
 {
-	printk("  stack:      %p-%p\n", stack, stack + sizeof(stack));
+	stack_walk();
 }
-
-

index b36f172..13e3274 100644
@@ -1,7 +1,9 @@
 #ifndef _KERNEL_H_
 #define _KERNEL_H_
 
-extern void do_exit(void) __attribute__((noreturn));
-extern void stop_kernel(void);
+void start_kernel(void);
+void do_exit(void) __attribute__((noreturn));
+void arch_do_exit(void);
+void stop_kernel(void);
 
 #endif /* _KERNEL_H_ */

index f193865..73b8297 100644
@@ -64,8 +64,6 @@ extern shared_info_t *HYPERVISOR_shared_info;
 void trap_init(void);
 void trap_fini(void);
 
-void arch_init(start_info_t *si);
-void arch_print_info(void);
 void arch_fini(void);
 
 

index 27e3c56..b9ab0a2 100644
@@ -114,41 +114,14 @@ __attribute__((weak)) int app_main(start_info_t *si)
     return 0;
 }
 
-/*
- * INITIAL C ENTRY POINT.
- */
-void start_kernel(start_info_t *si)
+void start_kernel(void)
 {
-    static char hello[] = "Bootstrapping...\n";
-
-    (void)HYPERVISOR_console_io(CONSOLEIO_write, strlen(hello), hello);
-
-    arch_init(si);
-
-    trap_init();
-
-    /* print out some useful information  */
-    printk("Xen Minimal OS!\n");
-    printk("  start_info: %p(VA)\n", si);
-    printk("    nr_pages: 0x%lx\n", si->nr_pages);
-    printk("  shared_inf: 0x%08lx(MA)\n", si->shared_info);
-    printk("     pt_base: %p(VA)\n", (void *)si->pt_base); 
-    printk("nr_pt_frames: 0x%lx\n", si->nr_pt_frames);
-    printk("    mfn_list: %p(VA)\n", (void *)si->mfn_list); 
-    printk("   mod_start: 0x%lx(VA)\n", si->mod_start);
-    printk("     mod_len: %lu\n", si->mod_len); 
-    printk("       flags: 0x%x\n", (unsigned int)si->flags);
-    printk("    cmd_line: %s\n",  
-           si->cmd_line ? (const char *)si->cmd_line : "NULL");
-
     /* Set up events. */
     init_events();
-    
+
     /* ENABLE EVENT DELIVERY. This is disabled at start of day. */
     __sti();
 
-    arch_print_info();
-
     setup_xen_features();
 
     /* Init memory management. */

@@ -201,13 +174,12 @@ void stop_kernel(void)
     /* Reset events. */
     fini_events();
 
-    /* Reset traps */
-    trap_fini();
-
     /* Reset arch details */
     arch_fini();
 }
 
+void arch_do_exit(void);
+
 /*
  * do_exit: This is called whenever an IRET fails in entry.S.
  * This will generally be because an application has got itself into

@@ -218,7 +190,7 @@ void stop_kernel(void)
 void do_exit(void)
 {
     printk("Do_exit called!\n");
-    stack_walk();
+    arch_do_exit();
     for( ;; )
     {
         struct sched_shutdown sched_shutdown = { .reason = SHUTDOWN_crash };

index 935bede..670c14f 100644
@@ -52,10 +52,10 @@
 #include <stddef.h>
 #include <xen/xen.h>
 #include <xen/event_channel.h>
-#include <sys/queue.h>
 #include "gntmap.h"
 
 #ifdef HAVE_LIBC
+#include <sys/queue.h>
 #include <stdio.h>
 #else
 #include <lib-gpl.h>

new file mode 100644
index 0000000..5fd637e
@@ -0,0 +1,24 @@
+#include <mini-os/os.h>
+#include <mini-os/events.h>
+#include <mini-os/hypervisor.h>
+
+static void virq_debug(evtchn_port_t port, struct pt_regs *regs, void *params)
+{
+    printk("Received a virq_debug event\n");
+}
+
+evtchn_port_t debug_port = -1;
+void arch_init_events(void) {
+    debug_port = bind_virq(VIRQ_DEBUG, (evtchn_handler_t)virq_debug, 0);
+    if(debug_port == -1)
+        BUG();
+    unmask_evtchn(debug_port);
+}
+
+void arch_fini_events(void) {
+    if(debug_port != -1)
+    {
+        mask_evtchn(debug_port);
+        unbind_evtchn(debug_port);
+    }
+}

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new file mode 100644
index 0000000..1306c1b
@@ -0,0 +1,37 @@
+#include <mini-os/sched.h>
+#include <mini-os/xmalloc.h>
+
+void arm_start_thread(void);
+
+/* Architecture specific setup of thread creation */
+struct thread* arch_create_thread(char *name, void (*function)(void *),
+                                  void *data)
+{
+    struct thread *thread;
+
+    thread = xmalloc(struct thread);
+    /* We can't use lazy allocation here since the trap handler runs on the stack */
+    thread->stack = (char *)alloc_pages(STACK_SIZE_PAGE_ORDER);
+    thread->name = name;
+    printk("Thread \"%s\": pointer: 0x%lx, stack: 0x%lx\n", name, thread,
+            thread->stack);
+
+    /* Save pointer to the thread on the stack, used by current macro */
+    *((unsigned long *)thread->stack) = (unsigned long)thread;
+
+    /* Push the details to pass to arm_start_thread onto the stack */
+    int *sp = (int *) (thread->stack + STACK_SIZE);
+    *(--sp) = (int) function;
+    *(--sp) = (int) data;
+    thread->sp = (unsigned long) sp;
+
+    thread->ip = (unsigned long) arm_start_thread;
+
+    return thread;
+}
+
+void run_idle_thread(void)
+{
+    __asm__ __volatile__ ("mov sp, %0; mov pc, %1"::"r"(idle_thread->sp), "r"(idle_thread->ip));
+    /* Never arrive here! */
+}

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index d60630b..79ba286 100644
@@ -246,7 +246,8 @@ int evtchn_bind_interdomain(domid_t pal, evtchn_port_t remote_port,
 
 int evtchn_get_peercontext(evtchn_port_t local_port, char *ctx, int size)
 {
-    int rc;
+    int rc = 0;
+#ifndef __arm__			/* TODO */
     uint32_t sid;
     struct xen_flask_op op;
     op.cmd = FLASK_GET_PEER_SID;

@@ -261,6 +262,7 @@ int evtchn_get_peercontext(evtchn_port_t local_port, char *ctx, int size)
     op.u.sid_context.size = size;
     set_xen_guest_handle(op.u.sid_context.context, ctx);
     rc = _hypercall1(int, xsm_op, &op);
+#endif
     return rc;
 }
 

index b4688a0..2a12ec4 100644
@@ -73,18 +73,26 @@ void do_hypervisor_callback(struct pt_regs *regs)
 
 void force_evtchn_callback(void)
 {
+#ifdef XEN_HAVE_PV_UPCALL_MASK
     int save;
+#endif
     vcpu_info_t *vcpu;
     vcpu = &HYPERVISOR_shared_info->vcpu_info[smp_processor_id()];
+#ifdef XEN_HAVE_PV_UPCALL_MASK
     save = vcpu->evtchn_upcall_mask;
+#endif
 
     while (vcpu->evtchn_upcall_pending) {
+#ifdef XEN_HAVE_PV_UPCALL_MASK
         vcpu->evtchn_upcall_mask = 1;
+#endif
         barrier();
         do_hypervisor_callback(NULL);
         barrier();
+#ifdef XEN_HAVE_PV_UPCALL_MASK
         vcpu->evtchn_upcall_mask = save;
         barrier();
+#endif
     };
 }
 

@@ -110,7 +118,9 @@ inline void unmask_evtchn(uint32_t port)
               &vcpu_info->evtchn_pending_sel) )
     {
         vcpu_info->evtchn_upcall_pending = 1;
+#ifdef XEN_HAVE_PV_UPCALL_MASK
         if ( !vcpu_info->evtchn_upcall_mask )
+#endif
             force_evtchn_callback();
     }
 }

new file mode 100644
index 0000000..bae99e1
@@ -0,0 +1,9 @@
+#ifndef __ARCH_LIMITS_H__
+#define __ARCH_LIMITS_H__
+
+#include <mm.h>
+
+#define __STACK_SIZE_PAGE_ORDER  2
+#define __STACK_SIZE (4 * PAGE_SIZE)
+
+#endif

new file mode 100644
index 0000000..5e3953b
@@ -0,0 +1,37 @@
+#ifndef _ARCH_MM_H_
+#define _ARCH_MM_H_
+
+extern char _text, _etext, _erodata, _edata, _end, __bss_start;
+extern char stack[];
+
+#define PAGE_SHIFT        12
+#define PAGE_SIZE        (1 << PAGE_SHIFT)
+#define PAGE_MASK       (~(PAGE_SIZE-1))
+
+#define L1_PAGETABLE_SHIFT      12
+
+#if 0
+#define VIRT_START                 ((unsigned long)&_text)
+#else
+#define VIRT_START                 ((unsigned long)0)
+#endif
+
+#define to_phys(x)                 ((unsigned long)(x)-VIRT_START)
+#define to_virt(x)                 ((void *)((unsigned long)(x)+VIRT_START))
+
+#define PFN_UP(x)    (((x) + PAGE_SIZE-1) >> L1_PAGETABLE_SHIFT)
+#define PFN_DOWN(x)    ((x) >> L1_PAGETABLE_SHIFT)
+#define PFN_PHYS(x)    ((uint64_t)(x) << L1_PAGETABLE_SHIFT)
+#define PHYS_PFN(x)    ((x) >> L1_PAGETABLE_SHIFT)
+
+#define virt_to_pfn(_virt)         (PFN_DOWN(to_phys(_virt)))
+#define virt_to_mfn(_virt)         (0)
+#define mach_to_virt(_mach)        (0)
+#define virt_to_mach(_virt)        (0)
+#define mfn_to_virt(_mfn)          (to_virt(PFN_PHYS(_mfn)))
+#define pfn_to_virt(_pfn)          (to_virt(PFN_PHYS(_pfn)))
+
+// FIXME
+#define map_frames(f, n) (NULL)
+
+#endif

new file mode 100644
index 0000000..e2307ed
@@ -0,0 +1,22 @@
+
+#ifndef __ARCH_SCHED_H__
+#define __ARCH_SCHED_H__
+
+#include "arch_limits.h"
+
+static inline struct thread* get_current(void)
+{
+   struct thread **current;
+   unsigned long sp;
+   __asm__ __volatile__ ("mov %0, sp":"=r"(sp));
+    current = (void *)(unsigned long)(sp & ~(__STACK_SIZE-1));
+    return *current;
+}
+
+
+extern void __arch_switch_threads(unsigned long *prevctx, unsigned long *nextctx);
+
+#define arch_switch_threads(prev,next) __arch_switch_threads(&(prev)->sp, &(next)->sp)
+
+
+#endif /* __ARCH_SCHED_H__ */

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new file mode 100644
index 0000000..704df22
@@ -0,0 +1,20 @@
+#ifndef _TRAPS_H_
+#define _TRAPS_H_
+
+struct pt_regs {
+    unsigned long r0;
+    unsigned long r1;
+    unsigned long r2;
+    unsigned long r3;
+    unsigned long r4;
+    unsigned long r5;
+    unsigned long r6;
+    unsigned long r7;
+    unsigned long r8;
+    unsigned long r9;
+    unsigned long r10;
+    unsigned long r11;
+    unsigned long r12;
+};
+
+#endif

new file mode 100644
index 0000000..cead2e5
@@ -0,0 +1 @@
+void gic_init(void);

index a62cb78..052f4f8 100644
@@ -18,6 +18,10 @@
 #include <hypercall-x86_32.h>
 #elif defined(__x86_64__)
 #include <hypercall-x86_64.h>
+#elif defined(__arm__)
+#include <hypercall-arm32.h>
+#elif defined(__aarch64__)
+#include <hypercall-arm64.h>
 #else
 #error "Unsupported architecture"
 #endif

index a94cd6d..644c7de 100644
@@ -29,6 +29,8 @@
 #include <xen/arch-x86_32.h>
 #elif defined(__x86_64__)
 #include <xen/arch-x86_64.h>
+#elif defined(__arm__) || defined(__aarch64__)
+#include <xen/arch-arm.h>
 #else
 #error "Unsupported architecture"
 #endif

index 6640ede..931e853 100644
@@ -27,7 +27,7 @@ typedef unsigned char       u_char;
 typedef unsigned int        u_int;
 typedef unsigned long       u_long;
 #endif
-#ifdef __i386__
+#if defined(__i386__) || defined(__arm__)
 typedef long long           quad_t;
 typedef unsigned long long  u_quad_t;
 

@@ -40,7 +40,7 @@ typedef unsigned long       u_quad_t;
 typedef struct { unsigned long pte; } pte_t;
 #endif /* __i386__ || __x86_64__ */
 
-#ifdef __x86_64__
+#if defined(__x86_64__) || defined(__aarch64__)
 #define __pte(x) ((pte_t) { (x) } )
 #else
 #define __pte(x) ({ unsigned long long _x = (x);        \

@@ -51,10 +51,10 @@ typedef struct { unsigned long pte; } pte_t;
 #include <limits.h>
 #include <stdint.h>
 #else
-#ifdef __i386__
+#if defined(__i386__) || defined(__arm__)
 typedef unsigned int        uintptr_t;
 typedef int                 intptr_t;
-#elif defined(__x86_64__)
+#elif defined(__x86_64__) || defined(__aarch64__)
 typedef unsigned long       uintptr_t;
 typedef long                intptr_t;
 #endif /* __i386__ || __x86_64__ */

@@ -64,10 +64,10 @@ typedef unsigned short uint16_t;
 typedef   signed short int16_t;
 typedef unsigned int uint32_t;
 typedef   signed int int32_t;
-#ifdef __i386__
+#if defined(__i386__) || defined(__arm__)
 typedef   signed long long int64_t;
 typedef unsigned long long uint64_t;
-#elif defined(__x86_64__)
+#elif defined(__x86_64__) || defined(__aarch64__)
 typedef   signed long int64_t;
 typedef unsigned long uint64_t;
 #endif

index b9ab0a2..cdf5928 100644
@@ -46,6 +46,10 @@
 #include <xen/features.h>
 #include <xen/version.h>
 
+#ifdef __arm__
+#include <mini-os/gic.h>
+#endif
+
 uint8_t xen_features[XENFEAT_NR_SUBMAPS * 32];
 
 void setup_xen_features(void)

@@ -146,6 +150,10 @@ void start_kernel(void)
     create_thread("shutdown", shutdown_thread, NULL);
 #endif
 
+#ifdef __arm__
+    gic_init();
+#endif
+
     /* Call (possibly overridden) app_main() */
     app_main(&start_info);
 

index 174945e..ed3f8c0 100644
@@ -145,6 +145,9 @@ struct thread* create_thread(char *name, void (*function)(void *), void *data)
     unsigned long flags;
     /* Call architecture specific setup. */
     thread = arch_create_thread(name, function, data);
+    if(!thread)
+    	BUG(); //For now, FIXME should just return NULL
+
     /* Not runable, not exited, not sleeping */
     thread->flags = 0;
     thread->wakeup_time = 0LL;