#include "threads/loader.h"
#include "threads/malloc.h"
#include "threads/mmu.h"
-#include "threads/paging.h"
#include "threads/palloc.h"
#include "threads/test.h"
#include "threads/thread.h"
/* Amount of physical memory, in 4 kB pages. */
size_t ram_pages;
+/* Page directory with kernel mappings only. */
+uint32_t *base_page_dir;
+
#ifdef FILESYS
/* Format the filesystem? */
static bool format_filesys;
static bool power_off;
static void ram_init (void);
+static void paging_init (void);
static void argv_init (void);
static void do_power_off (void);
ram_pages = *(uint32_t *) ptov (LOADER_RAM_PAGES);
}
+/* Populates the base page directory and page table with the
+ kernel virtual mapping, and then sets up the CPU to use the
+ new page directory. Points base_page_dir to the page
+ directory it creates.
+
+ At the time this function is called, the active page table
+ (set up by loader.S) only maps the first 4 MB of RAM, so we
+ should not try to use extravagant amounts of memory.
+ Fortunately, there is no need to do so. */
+static void
+paging_init (void)
+{
+ uint32_t *pd, *pt;
+ size_t page;
+
+ pd = base_page_dir = palloc_get (PAL_ASSERT | PAL_ZERO);
+ pt = NULL;
+ for (page = 0; page < ram_pages; page++)
+ {
+ uintptr_t paddr = page * PGSIZE;
+ void *vaddr = ptov (paddr);
+ size_t pde_idx = pd_no (vaddr);
+ size_t pte_idx = pt_no (vaddr);
+
+ if (pd[pde_idx] == 0)
+ {
+ pt = palloc_get (PAL_ASSERT | PAL_ZERO);
+ pd[pde_idx] = pde_create (pt);
+ }
+
+ pt[pte_idx] = pte_create_kernel (vaddr, true);
+ }
+
+ asm volatile ("movl %0,%%cr3" :: "r" (vtop (base_page_dir)));
+}
+
/* Parses the command line. */
static void
argv_init (void)
/* The command line is made up of null terminated strings
followed by an empty string. Break it up into words. */
cmd_line = pos = ptov (LOADER_CMD_LINE);
+ printf ("Kernel command line:");
while (pos < cmd_line + LOADER_CMD_LINE_LEN)
{
ASSERT (argc < LOADER_CMD_LINE_LEN / 2);
if (*pos == '\0')
break;
argv[argc++] = pos;
+ printf (" %s", pos);
pos = strchr (pos, '\0') + 1;
}
+ printf ("\n");
argv[argc] = "";
argv[argc + 1] = "";
" -D Dump complete filesystem contents\n"
#endif
" -q Power off after doing requested actions.\n"
+ " -u Print this help message and power off.\n"
);
+ do_power_off ();
}
else
- PANIC ("unknown option `%s'", argv[i]);
+ PANIC ("unknown option `%s' (use -u for help)", argv[i]);
}
+/* Powers down the machine we're running on,
+ as long as we're running on Bochs or qemu. */
void
do_power_off (void)
{