josh/hos
1
0
Fork 0
Code Issues 1 Pull Requests Projects Releases Wiki Activity

Moved page_directory from an allocated object to a pointer to a run-time allocated page of RAM

Browse Source 
git-svn-id: svn://anubis/hos/trunk@42 5b3e749e-e535-0410-8002-a9bb6afbdfca
This commit is contained in:
josh 2009-07-06 21:48:04 +00:00
parent 784978b131
commit 1aace858da
2 changed files with 24 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
kernel/mm/mm.cc
View File

@ -8,8 +8,7 @@
static bool mm_use_virtual_offset;
pagedirectory_t page_directory __attribute__ ((aligned (4096)));
static pagedirectory_entry_t * page_directory;
static mm_mem_range_t mm_mmap_entries[MM_MAX_MMAP_ENTRIES];
static int mm_mmap_num_entries = 0;
static int mm_num_free_pages = 0;
@ -108,10 +107,18 @@ void mm_bootstrap()
k_early_panic("Not enough free pages of RAM!");
}
/* ok, now mm_page_alloc() should be functional */
/* allocate the page directory */
u32_t page_directory_phys = mm_page_alloc();
page_directory = (pagedirectory_entry_t *) page_directory_phys;
pagedirectory_entry_t * page_dir_virt =
(pagedirectory_entry_t *) (page_directory_phys + KERNEL_OFFSET);
/* Clear the page directory */
for (unsigned int i = 0; i < NUM_PAGETABLE_ENTRIES; i++)
{
page_directory[i] = 0;
page_dir_virt[i] = 0;
}
/*
@ -135,7 +142,7 @@ void mm_bootstrap()
}
/* set the page directory base register */
set_cr3(&page_directory);
set_cr3(page_directory);
mm_use_virtual_offset = false;
}
@ -149,7 +156,13 @@ int mm_map(u32_t virtual_address, u32_t physical_address,
{
u32_t directory_index = (virtual_address >> 22) & 0x3FF;
u32_t table_index = (virtual_address >> 12) & 0x3FF;
if (page_directory[directory_index] == 0)
pagedirectory_entry_t * page_dir = page_directory;
if (mm_use_virtual_offset)
{
page_dir = (pagedirectory_entry_t *)((u32_t)page_dir + KERNEL_OFFSET);
}
if (page_dir[directory_index] == 0)
{
/* allocate a new page table */
u32_t page_table_address = mm_page_alloc();
@ -157,12 +170,12 @@ int mm_map(u32_t virtual_address, u32_t physical_address,
{
return 0;
}
page_directory[directory_index] = page_table_address
page_dir[directory_index] = page_table_address
| 0x1 << 2 /* PTs can be user mode */
| 0x1 << 1 /* writable */
| 0x1; /* present */
}
u32_t page_table_address = page_directory[directory_index] & PAGE_HIGH_MASK;
u32_t page_table_address = page_dir[directory_index] & PAGE_HIGH_MASK;
u32_t * page_table = (u32_t *) page_table_address;
if (mm_use_virtual_offset)

5
kernel/mm/mm.h
View File

@ -10,10 +10,7 @@ typedef u32_t pagedirectory_entry_t;
#define NUM_PAGETABLE_ENTRIES (PAGE_SIZE / sizeof(pagedirectory_entry_t))
typedef pagedirectory_entry_t
pagedirectory_t[NUM_PAGETABLE_ENTRIES];
extern pagedirectory_t page_directory;
typedef pagedirectory_entry_t pagedirectory_t[NUM_PAGETABLE_ENTRIES];
typedef struct
{