#include "thread.h"
#include "timer.h"
#include "vga.h"
+#ifdef USERPROG
+#include "exception.h"
+#include "syscall.h"
+#include "gdt.h"
+#include "tss.h"
+#endif
#ifdef FILESYS
#include "filesys.h"
#include "disk.h"
#endif
static void ram_init (void);
-static void gdt_init (void);
static void argv_init (void);
-static void
-main_thread (void *aux UNUSED)
-{
-#ifdef FILESYS
- disk_init ();
- filesys_init (format_filesys);
- fsutil_run ();
-#endif
-
-#ifdef USERPROG
- if (initial_program != NULL)
- thread_execute (initial_program);
- else
- PANIC ("no initial program specified");
-#endif
-}
+int main (void) NO_RETURN;
int
main (void)
{
- /* Initialize prerequisites for calling printk(). */
+ /* Needed by printk(), so initialize them very early. */
ram_init ();
vga_init ();
serial_init ();
/* Parse command line. */
argv_init ();
- /* Initialize memory system. */
+ /* Initialize memory system, segments, paging. */
+ thread_init ();
palloc_init ();
paging_init ();
+#ifdef USERPROG
+ tss_init ();
gdt_init ();
+#endif
malloc_init ();
+ /* Set random seed if not already done. */
random_init (0);
/* Initialize interrupt handlers. */
intr_init ();
timer_init ();
kbd_init ();
+#ifdef USERPROG
+ exception_init ();
+ syscall_init ();
+#endif
- /* Do everything else in a system thread. */
- thread_init ();
- thread_create ("main", main_thread, NULL);
+ /* Start thread scheduler and enable interrupts. */
thread_start ();
-}
-
-static uint64_t
-make_seg_desc (uint32_t base,
- uint32_t limit,
- enum seg_system system,
- enum seg_type type,
- int dpl,
- enum seg_granularity granularity)
-{
- uint32_t e0 = ((limit & 0xffff) /* Limit 15:0. */
- | (base << 16)); /* Base 15:0. */
- uint32_t e1 = (((base >> 16) & 0xff) /* Base 23:16. */
- | (system << 12) /* 0=system, 1=code/data. */
- | (type << 8) /* Segment type. */
- | (dpl << 13) /* Descriptor privilege. */
- | (1 << 15) /* Present. */
- | (limit & 0xf0000) /* Limit 16:19. */
- | (1 << 22) /* 32-bit segment. */
- | (granularity << 23) /* Byte/page granularity. */
- | (base & 0xff000000)); /* Base 31:24. */
- return e0 | ((uint64_t) e1 << 32);
-}
-static uint64_t
-make_code_desc (int dpl)
-{
- return make_seg_desc (0, 0xfffff, SYS_CODE_DATA, TYPE_CODE | TYPE_READABLE,
- dpl, GRAN_PAGE);
-}
-
-static uint64_t
-make_data_desc (int dpl)
-{
- return make_seg_desc (0, 0xfffff, SYS_CODE_DATA, TYPE_WRITABLE,
- dpl, GRAN_PAGE);
-}
-
-static uint64_t
-make_tss_desc (void *vaddr)
-{
- return make_seg_desc ((uint32_t) vaddr,
- 0x67, SYS_SYSTEM, TYPE_TSS_32_A, 0, GRAN_BYTE);
-}
+#ifdef FILESYS
+ /* Initialize filesystem. */
+ disk_init ();
+ filesys_init (format_filesys);
+ fsutil_run ();
+#endif
-static uint64_t gdt[SEL_CNT];
+ printk ("Boot complete.\n");
-struct tss *tss;
+#ifdef USERPROG
+ /* Run a user program. */
+ if (initial_program != NULL)
+ {
+ printk ("\nExecuting '%s':\n", initial_program);
+ thread_execute (initial_program);
+ }
+#endif
-/* Sets up a proper GDT. The bootstrap loader's GDT didn't
- include user-mode selectors or a TSS. */
-static void
-gdt_init (void)
-{
- uint64_t gdtr_operand;
-
- /* Our TSS is never used in a call gate or task gate, so only a
- few fields of it are ever referenced, and those are the only
- ones we initialize. */
- tss = palloc_get (PAL_ASSERT | PAL_ZERO);
- tss->esp0 = (uint32_t) ptov(0x20000);
- tss->ss0 = SEL_KDSEG;
- tss->bitmap = 0xdfff;
-
- /* Initialize GDT. */
- gdt[SEL_NULL / sizeof *gdt] = 0;
- gdt[SEL_KCSEG / sizeof *gdt] = make_code_desc (0);
- gdt[SEL_KDSEG / sizeof *gdt] = make_data_desc (0);
- gdt[SEL_UCSEG / sizeof *gdt] = make_code_desc (3);
- gdt[SEL_UDSEG / sizeof *gdt] = make_data_desc (3);
- gdt[SEL_TSS / sizeof *gdt] = make_tss_desc (tss);
-
- /* Load GDTR, TR. */
- gdtr_operand = make_dtr_operand (sizeof gdt - 1, gdt);
- asm volatile ("lgdt %0" :: "m" (gdtr_operand));
- asm volatile ("ltr %w0" :: "r" (SEL_TSS));
+ /* Terminate this thread. */
+ thread_exit ();
}
-
+\f
+/* Clear BSS and obtain RAM size from loader. */
static void
ram_init (void)
{
extern char _start_bss, _end_bss;
memset (&_start_bss, 0, &_end_bss - &_start_bss);
- /* Get RAM size from loader. */
+ /* Get RAM size from loader. See loader.S. */
ram_pages = *(uint32_t *) ptov (LOADER_RAM_PAGES);
}
-\f
+
+/* Parses the command line. */
static void
argv_init (void)
{
" -p FILENAME Print the contents of FILENAME\n"
" -r FILENAME Delete FILENAME\n"
" -ls List the files in the filesystem\n"
- " -D Dump complete filesystem contents\n");
+ " -D Dump complete filesystem contents\n"
#endif
+ );
}
else
PANIC ("unknown option `%s'", argv[i]);