diff options
Diffstat (limited to 'kernel/features/mm.c')
| -rw-r--r-- | kernel/features/mm.c | 39 |
1 files changed, 22 insertions, 17 deletions
diff --git a/kernel/features/mm.c b/kernel/features/mm.c index cde9a94..c39b8b7 100644 --- a/kernel/features/mm.c +++ b/kernel/features/mm.c @@ -6,7 +6,6 @@ #include <def.h> #include <mem.h> #include <mm.h> - #include <print.h> static struct page_dir kernel_dir ALIGNED(PAGE_SIZE) = { 0 }; @@ -138,7 +137,7 @@ static u8 physical_is_used(struct memory_range range) return 0; } -static struct memory_range physical_alloc(u32 size) +struct memory_range physical_alloc(u32 size) { assert(PAGE_ALIGNED(size)); @@ -165,34 +164,34 @@ static void physical_free(struct memory_range range) * Virtual */ -#define PDI(vaddr) ((vaddr) >> 22) +#define PDI(vaddr) (((vaddr) >> 22) & 0x03ff) #define PTI(vaddr) (((vaddr) >> 12) & 0x03ff) u8 virtual_present(struct page_dir *dir, u32 vaddr) { u32 pdi = PDI(vaddr); - u32 pti = PTI(vaddr); - union page_dir_entry *dir_entry = &dir->entries[pdi]; if (!dir_entry->bits.present) return 0; struct page_table *table = (struct page_table *)(dir_entry->bits.address * PAGE_SIZE); + + u32 pti = PTI(vaddr); union page_table_entry *table_entry = &table->entries[pti]; - return !table_entry->bits.present; + return table_entry->bits.present; } u32 virtual_to_physical(struct page_dir *dir, u32 vaddr) { u32 pdi = PDI(vaddr); - u32 pti = PTI(vaddr); - union page_dir_entry *dir_entry = &dir->entries[pdi]; if (!dir_entry->bits.present) return 0; struct page_table *table = (struct page_table *)(dir_entry->bits.address * PAGE_SIZE); + + u32 pti = PTI(vaddr); union page_table_entry *table_entry = &table->entries[pti]; if (!table_entry->bits.present) return 0; @@ -204,9 +203,8 @@ void virtual_map(struct page_dir *dir, struct memory_range prange, u32 vaddr, u3 { for (u32 i = 0; i < prange.size / PAGE_SIZE; i++) { u32 offset = i * PAGE_SIZE; - u32 pdi = PDI(vaddr + offset); - u32 pti = PTI(vaddr + offset); + u32 pdi = PDI(vaddr + offset); union page_dir_entry *dir_entry = &dir->entries[pdi]; struct page_table *table = (struct page_table *)(dir_entry->bits.address * PAGE_SIZE); @@ -219,6 +217,7 @@ void virtual_map(struct page_dir *dir, struct memory_range prange, u32 vaddr, u3 dir_entry->bits.address = (u32)(table) >> 12; } + u32 pti = PTI(vaddr + offset); union page_table_entry *table_entry = &table->entries[pti]; table_entry->bits.present = 1; table_entry->bits.writable = 1; @@ -263,14 +262,14 @@ void virtual_free(struct page_dir *dir, struct memory_range vrange) u32 offset = i * PAGE_SIZE; u32 pdi = PDI(vrange.base + offset); - u32 pti = PTI(vrange.base + offset); - union page_dir_entry *dir_entry = &dir->entries[pdi]; if (!dir_entry->bits.present) continue; struct page_table *table = (struct page_table *)(dir_entry->bits.address * PAGE_SIZE); + + u32 pti = PTI(vrange.base + offset); union page_table_entry *table_entry = &table->entries[pti]; if (table_entry->bits.present) @@ -284,12 +283,14 @@ struct page_dir *virtual_create_dir(void) { struct page_dir *dir = memory_alloc(&kernel_dir, sizeof(*dir), MEMORY_CLEAR); + memset(dir, 0, sizeof(*dir)); + for (u32 i = 0; i < 256; i++) { union page_dir_entry *dir_entry = &dir->entries[i]; - dir_entry->bits.user = 0; - dir_entry->bits.writable = 1; dir_entry->bits.present = 1; + dir_entry->bits.writable = 1; + dir_entry->bits.user = 0; dir_entry->bits.address = (u32)&kernel_tables[i] / PAGE_SIZE; } @@ -334,22 +335,26 @@ void *memory_alloc(struct page_dir *dir, u32 size, u32 flags) assert(PAGE_ALIGNED(size)); if (!size) - return 0; + goto err; struct memory_range prange = physical_alloc(size); if (prange.size == 0) - return 0; + goto err; u32 vaddr = virtual_alloc(dir, prange, flags).base; if (!vaddr) { physical_free(prange); - return 0; + goto err; } if (flags & MEMORY_CLEAR) memset((void *)vaddr, 0, size); return (void *)vaddr; + +err: + print("Memory allocation error!\n"); + return 0; } void *memory_alloc_identity(struct page_dir *dir, u32 flags) |