1 files changed, 69 insertions, 0 deletions
diff --git a/core/thread/start_thread.c b/core/thread/start_thread.c
new file mode 100644
index 0000000..2e4320a
--- /dev/null
+++ b/core/thread/start_thread.c
@@ -0,0 +1,69 @@
+#include <string.h>
+#include <stdlib.h>
+#include <com32.h>
+#include "core.h"
+#include "thread.h"
+
+#define REAL_MODE_STACK_SIZE	4096
+#define MIN_STACK_SIZE		16384
+#define THREAD_ALIGN		64 	/* Thread alignment */
+
+extern void __start_thread(void);
+
+struct thread *start_thread(const char *name, size_t stack_size, int prio,
+			    void (*start_func)(void *), void *func_arg)
+{
+    irq_state_t irq;
+    struct thread *curr, *t;
+    char *stack, *rmstack;
+    const size_t thread_mask = THREAD_ALIGN - 1;
+    struct thread_stack *sp;
+
+    if (stack_size < MIN_STACK_SIZE)
+	stack_size = MIN_STACK_SIZE;
+
+    stack_size = (stack_size + thread_mask) & ~thread_mask;
+    stack = malloc(stack_size + sizeof(struct thread));
+    if (!stack)
+	return NULL;
+    rmstack = lmalloc(REAL_MODE_STACK_SIZE);
+    if (!rmstack) {
+	free(stack);
+	return NULL;
+    }
+
+    t = (struct thread *)stack;
+    memset(t, 0, sizeof *t);
+    t->stack   = stack;
+    t->rmstack = rmstack;
+    stack += sizeof(struct thread);
+
+    /* sp allocated from the end of the stack */
+    sp = (struct thread_stack *)(stack + stack_size) - 1;
+    t->esp = sp;
+
+    sp->errno = 0;
+    sp->rmss = SEG(rmstack);
+    sp->rmsp = REAL_MODE_STACK_SIZE;
+    sp->esi = (size_t)start_func;
+    sp->edi = (size_t)func_arg;
+    sp->ebx = irq_state();	/* Inherit the IRQ state from the spawner */
+    sp->eip = __start_thread;
+    t->prio = prio;
+    t->name = name;
+
+    irq = irq_save();
+    curr = current();
+
+    t->thread_magic    = THREAD_MAGIC;
+
+    t->list.prev       = &curr->list;
+    t->list.next       = curr->list.next;
+    curr->list.next    = &t->list;
+    t->list.next->prev = &t->list;
+
+    __schedule();
+
+    irq_restore(irq);
+    return t;
+}