Clean up threads.c.

[pintos-anon] / src / threads / init.c

diff --git a/src/threads/init.c b/src/threads/init.c
index da1a98c69da9bcd70374255b98bf591d106b1051..03e0bb8bec1c1bfb7405f4ebef11c8af7a2ac369 100644 (file)
--- a/src/threads/init.c
+++ b/src/threads/init.c
@@ -7,6 +7,7 @@
 #include "io.h"
 #include "kbd.h"
 #include "lib.h"
+#include "loader.h"
 #include "malloc.h"
 #include "mmu.h"
 #include "paging.h"
@@ -18,69 +19,53 @@
 #include "vga.h"
 #ifdef FILESYS
 #include "filesys.h"
+#include "disk.h"
 #endif
 
-/* Size of kernel static code and data, in 4 kB pages. */
-size_t kernel_pages;
-
 /* Amount of physical memory, in 4 kB pages. */
 size_t ram_pages;
 
+static void ram_init (void);
 static void gdt_init (void);
-void power_off (void);
+static void argv_init (void);
 
 static void
 main_thread (void *aux UNUSED) 
 {
-  printk ("execute=%d\n", (int) thread_execute ("a.out"));
+#ifdef FILESYS
+  disk_init ();
+  filesys_init (true);
+  filesys_self_test ();
+#endif
 }
 
 int
 main (void)
 {
-  extern char _text, _end, __bss_start;
-  struct thread *t;
-
-  /* Clear out the BSS segment. */
-  memset (&__bss_start, 0, &_end - &__bss_start);
-
+  /* Initialize prerequisites for calling printk(). */
+  ram_init ();
   vga_init ();
   serial_init ();
 
-  /* Calculate how much RAM the kernel uses, and find out from
-     the bootloader how much RAM this machine has. */
-  kernel_pages = (&_end - &_text + 4095) / 4096;
-  ram_pages = *(uint32_t *) (0x7e00 - 8);
-
-  printk ("Initializing nachos-x86, %d kB RAM detected.\n",
-          ram_pages * 4);
+  /* Greet user. */
+  printk ("Booting cnachos86 with %'d kB RAM...\n", ram_pages * 4);
 
-  /* Memory from the end of the kernel through the end of memory
-     is free.  Give it to the page allocator. */
-  palloc_init ((void *) (KERN_BASE + kernel_pages * PGSIZE),
-               (void *) (PHYS_BASE + ram_pages * PGSIZE));
+  /* Initialize memory system. */
+  palloc_init ();
   paging_init ();
   gdt_init ();
-
   malloc_init ();
+
   random_init ();
+  argv_init ();
 
+  /* Initialize interrupt handlers. */
   intr_init ();
   timer_init ();
   kbd_init ();
 
-#ifdef FILESYS
-  filesys_init (false);
-  filesys_self_test ();
-#endif
-
-  thread_init ();
-
-  t = thread_create ("main", main_thread, NULL);
-  thread_start (t);
-
-  printk ("Done!\n");
-  return 0;
+  /* Do everything else in a system thread. */
+  thread_init ("main", main_thread, NULL);
 }
 
 static uint64_t
@@ -94,13 +79,13 @@ make_seg_desc (uint32_t base,
   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. */
+                 | (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. */
+                 | (granularity << 23)        /* Byte/page granularity. */
                  | (base & 0xff000000));      /* Base 31:24. */
   return e0 | ((uint64_t) e1 << 32);
 }
@@ -120,12 +105,13 @@ make_data_desc (int dpl)
 }
 
 static uint64_t
-make_tss_desc (uint32_t base)
+make_tss_desc (void *vaddr)
 {
-  return make_seg_desc (base, 0x67, SYS_SYSTEM, TYPE_TSS_32_A, 0, GRAN_BYTE);
+  return make_seg_desc ((uint32_t) vaddr,
+                        0x67, SYS_SYSTEM, TYPE_TSS_32_A, 0, GRAN_BYTE);
 }
 
-uint64_t gdt[SEL_CNT];
+static uint64_t gdt[SEL_CNT];
 
 struct tss *tss;
 
@@ -150,22 +136,48 @@ gdt_init (void)
   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 (vtop (tss));
+  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));
 }
-\f
-void
-power_off (void) 
+
+static void
+ram_init (void) 
 {
-  const char s[] = "Shutdown";
-  const char *p;
+  /* The "BSS" is a segment that should be initialized to zeros.
+     It isn't actually stored on disk or zeroed by the kernel
+     loader, so we have to zero it ourselves.
+
+     The start and end of the BSS segment is recorded by the
+     linker as _start_bss and _end_bss.  See kernel.lds. */
+  extern char _start_bss, _end_bss;
+  memset (&_start_bss, 0, &_end_bss - &_start_bss);
 
-  printk ("Powering off...\n");
-  for (p = s; *p != '\0'; p++)
-    outb (0x8900, *p);
-  for (;;);
+  /* Get RAM size from loader. */
+  ram_pages = *(uint32_t *) ptov (LOADER_RAM_PAGES);
+}
+\f
+/* This should be sufficient because the command line buffer is
+   only 128 bytes and arguments are space-delimited. */
+#define ARGC_MAX 64
+
+int argc;
+char *argv[ARGC_MAX + 1];
+
+static void
+argv_init (void) 
+{
+  char *cmd_line = ptov (LOADER_CMD_LINE);
+  char *arg, *pos;
+
+  for (arg = strtok_r (cmd_line, " \t\r\n\v", &pos); arg != NULL;
+       arg = strtok_r (NULL, " \t\r\n\v", &pos))
+    {
+      ASSERT (argc < ARGC_MAX);
+      argv[argc++] = arg;
+    }
+  argv[argc] = NULL;
 }