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fixed bug that mapping PAGE_DIR_SELF_REF would incorrectly allocate a new physical page

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git-svn-id: svn://anubis/hos/trunk@101 5b3e749e-e535-0410-8002-a9bb6afbdfca
This commit is contained in:
josh 2010-02-01 05:04:39 +00:00
parent 563758b1bd
commit 4b688a3ce0
1 changed files with 19 additions and 13 deletions
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32
kernel/mm/mm.cc
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@ -147,7 +147,8 @@ void mm_bootstrap()
/* ok, now mm_early_map() should be functional */ /* ok, now mm_early_map() should be functional */
/* map in the page directory itself so we can modify it once paging is on */ /* map in the page directory itself so we can modify it once paging is on */
mm_early_map(PAGE_DIR_SELF_REF2, page_directory_phys, 0, 1); (*early_page_directory_ptr)[PAGE_DIR_SELF_REF_INDEX] =
(page_directory_phys) | (0x1 << 1) | (0x1);
/* map in the physical page allocator pages */ /* map in the physical page allocator pages */
for (int i = 0; i <= last_page_alloc_page; i++) for (int i = 0; i <= last_page_alloc_page; i++)
@ -250,14 +251,14 @@ int mm_early_map(u32_t virtual_address, u32_t physical_address,
} }
pagedirectory_entry_t * page_table_virt = (pagedirectory_entry_t *) pagedirectory_entry_t * page_table_virt = (pagedirectory_entry_t *)
(page_table_phys + KERNEL_OFFSET); (page_table_phys + KERNEL_OFFSET);
for (int i = 0; i < NUM_PAGETABLE_ENTRIES; i++) for (unsigned int i = 0; i < NUM_PAGETABLE_ENTRIES; i++)
{ {
page_table_virt[i] = 0; page_table_virt[i] = 0;
} }
(*early_page_directory_ptr)[directory_index] = page_table_phys (*early_page_directory_ptr)[directory_index] = page_table_phys
| 0x1 << 2 /* PTs can be user mode */ | (0x1 << 2) /* PTs can be user mode */
| 0x1 << 1 /* writable */ | (0x1 << 1) /* writable */
| 0x1; /* present */ | (0x1); /* present */
} }
u32_t page_table_phys = u32_t page_table_phys =
(*early_page_directory_ptr)[directory_index] & PAGE_HIGH_MASK; (*early_page_directory_ptr)[directory_index] & PAGE_HIGH_MASK;
@ -266,8 +267,8 @@ int mm_early_map(u32_t virtual_address, u32_t physical_address,
(pagedirectory_entry_t *) (page_table_phys + KERNEL_OFFSET); (pagedirectory_entry_t *) (page_table_phys + KERNEL_OFFSET);
page_table[table_index] = (physical_address & PAGE_HIGH_MASK) page_table[table_index] = (physical_address & PAGE_HIGH_MASK)
| (user_mode & 0x1) << 2 | ((user_mode & 0x1) << 2)
| (writable & 0x1) << 1 | ((writable & 0x1) << 1)
| 0x1; /* present */ | 0x1; /* present */
return 1; return 1;
@ -294,18 +295,23 @@ int mm_map(u32_t virtual_address, u32_t physical_address,
return 0; return 0;
} }
*page_dir_entry = page_table_phys *page_dir_entry = page_table_phys
| 0x1 << 2 /* PTs can be user mode */ | (0x1 << 2) /* PTs can be user mode */
| 0x1 << 1 /* writable */ | (0x1 << 1) /* writable */
| 0x1; /* present */ | (0x1); /* present */
/* FIXME pagedirectory_entry_t * page_table = */ pagedirectory_entry_t * page_table = (pagedirectory_entry_t *)
(PAGE_DIR_SELF_REF | (directory_index << 12));
for (unsigned int i = 0; i < NUM_PAGETABLE_ENTRIES; i++)
{
page_table[i] = 0;
}
} }
pagedirectory_entry_t * page_table_entry = (pagedirectory_entry_t *) pagedirectory_entry_t * page_table_entry = (pagedirectory_entry_t *)
(PAGE_DIR_SELF_REF | (directory_index << 12) | (table_index << 2)); (PAGE_DIR_SELF_REF | (directory_index << 12) | (table_index << 2));
*page_table_entry = (physical_address & PAGE_HIGH_MASK) *page_table_entry = (physical_address & PAGE_HIGH_MASK)
| (user_mode & 0x1) << 2 | ((user_mode & 0x1) << 2)
| (writable & 0x1) << 1 | ((writable & 0x1) << 1)
| 0x1; /* present */ | 0x1; /* present */
return 1; return 1;