1 #include <string.h>
2 #include <stdlib.h>
3 #include <com32.h>
4 #include "core.h"
5 #include "thread.h"
6
7 #define REAL_MODE_STACK_SIZE 4096
8 #define MIN_STACK_SIZE 16384
9 #define THREAD_ALIGN 64 /* Thread alignment */
10
11 extern void __start_thread(void);
12
start_thread(const char * name,size_t stack_size,int prio,void (* start_func)(void *),void * func_arg)13 struct thread *start_thread(const char *name, size_t stack_size, int prio,
14 void (*start_func)(void *), void *func_arg)
15 {
16 irq_state_t irq;
17 struct thread *curr, *t;
18 char *stack, *rmstack;
19 const size_t thread_mask = THREAD_ALIGN - 1;
20 struct thread_stack *sp;
21
22 if (stack_size < MIN_STACK_SIZE)
23 stack_size = MIN_STACK_SIZE;
24
25 stack_size = (stack_size + thread_mask) & ~thread_mask;
26 stack = malloc(stack_size + sizeof(struct thread));
27 if (!stack)
28 return NULL;
29 rmstack = lmalloc(REAL_MODE_STACK_SIZE);
30 if (!rmstack) {
31 free(stack);
32 return NULL;
33 }
34
35 t = (struct thread *)stack;
36 memset(t, 0, sizeof *t);
37 t->stack = stack;
38 t->rmstack = rmstack;
39 stack += sizeof(struct thread);
40
41 /* sp allocated from the end of the stack */
42 sp = (struct thread_stack *)(stack + stack_size) - 1;
43 t->esp = sp;
44
45 sp->errno = 0;
46 sp->rmss = SEG(rmstack);
47 sp->rmsp = REAL_MODE_STACK_SIZE;
48 sp->esi = (size_t)start_func;
49 sp->edi = (size_t)func_arg;
50 sp->ebx = irq_state(); /* Inherit the IRQ state from the spawner */
51 sp->eip = __start_thread;
52 t->prio = prio;
53 t->name = name;
54
55 irq = irq_save();
56 curr = current();
57
58 t->thread_magic = THREAD_MAGIC;
59
60 t->list.prev = &curr->list;
61 t->list.next = curr->list.next;
62 curr->list.next = &t->list;
63 t->list.next->prev = &t->list;
64
65 __schedule();
66
67 irq_restore(irq);
68 return t;
69 }
70