diff options
Diffstat (limited to 'kernel/include/mm/virtual_mm.h')
| -rw-r--r-- | kernel/include/mm/virtual_mm.h | 52 |
1 files changed, 39 insertions, 13 deletions
diff --git a/kernel/include/mm/virtual_mm.h b/kernel/include/mm/virtual_mm.h index fce10bc..fa7f505 100644 --- a/kernel/include/mm/virtual_mm.h +++ b/kernel/include/mm/virtual_mm.h @@ -26,6 +26,9 @@ #define PAGE_DIRECTORY_SIZE 1024 #define PAGE_TABLE_SIZE 1024 +#define PAGE_DIRECTORY_INDEX(virtual_address) ((virtual_address >> 22) & 0x3ff) +#define PAGE_TABLE_INDEX(virtual_address) ((virtual_address >> 12) & 0x3ff) + #define PDE_PRESENT 1 #define PDE_WRITABLE (1 << 1) #define PDE_USER (1 << 2) @@ -41,24 +44,47 @@ /* Page table address */ #define PDE_FRAME(x) (x << 11) -#define PTE_PRESENT 1 -#define PTE_WRITABLE (1 << 1) -#define PTE_USER (1 << 2) -#define PTE_WRITETHROUGH (1 << 3) -#define PTE_CACHE_DISABLE (1 << 4) -#define PTE_ACCESSED (1 << 5) -#define PTE_DIRTY (1 << 6) -#define PTE_PAT (1 << 7) -#define PTE_GLOBAL (1 << 8) +#define SET_PTE_PRESENT(x) x +#define SET_PTE_WRITABLE(x) (x << 1) +#define SET_PTE_USER(x) (x << 2) +#define SET_PTE_WRITETHROUGH(x) (x << 3) +#define SET_PTE_CACHE_DISABLE(x) (x << 4) +#define SET_PTE_ACCESSED(x) (x << 5) +#define SET_PTE_DIRTY(x) (x << 6) +#define SET_PTE_PAT(x) (x << 7) +#define SET_PTE_GLOBAL(x) (x << 8) /* NOTE: Unused by the CPU, free to be used by us! */ -#define PTE_UNUSED(x) (x << 9) +#define SET_PTE_UNUSED(x) (x << 9) /* MAX: 0xFFFFF000 */ -#define PTE_FRAME(x) (x << 11) +#define SET_PTE_FRAME(x) (x << 11) + +#define GET_PTE_FRAME(x) (*x >> 11) #define ADD_ATTRIB(entry, attribute) (*entry |= (attribute)) -#define SET_FRAME(entry, frame) \ - (ADD_ATTRIB(entry, PTE_FRAME((uint32_t) frame))) +/* + * Given a page table entry, it sets the frame to a newly allocated address, + * and sets the present bit to false. + */ bool virtual_mm_allocate_page(uint32_t *pt_entry); +/* + * Given a page table entry, it sets the entry to 0 (therefore zero-ing the + * frame and present bit). + */ +bool virtual_mm_free_page(uint32_t *pt_entry); + +/* + * Given a page table and virtual address, it returns a pointer to the page + * table entry referenced by the virtual address. + */ +uint32_t *virtual_mm_lookup_table(uint32_t *page_table, uint32_t virtual_addr); + +/* + * Given a page directory and virtual address, it returns a pointer to the page + * directory entry referenced by the virtual address. + */ +uint32_t *virtual_mm_lookup_directory(uint32_t *page_directory, + uint32_t virtual_addr); + #endif |