diff options
Diffstat (limited to 'kernel/src/memory/memory.c')
| -rw-r--r-- | kernel/src/memory/memory.c | 202 |
1 files changed, 0 insertions, 202 deletions
diff --git a/kernel/src/memory/memory.c b/kernel/src/memory/memory.c deleted file mode 100644 index 30da0fc..0000000 --- a/kernel/src/memory/memory.c +++ /dev/null @@ -1,202 +0,0 @@ -#include <stdint.h> -#include <string.h> -#include <sys.h> -#include <panic.h> - -#include "memory.h" -#include "boot/tag.h" -#include "print.h" - -struct MemoryArea { - uint32_t len; - struct MemoryArea *prev; - struct MemoryArea *next; -}; - -typedef unsigned char page[4096]; - -extern unsigned char kernel_start, kernel_end; -static uintptr_t kernel_start_addr, kernel_end_addr; -static uint32_t *bitmap; -static uint32_t total_memory; -static uint32_t free_memory; -static uint32_t page_count; -static uint32_t page_free_start; -static struct MemoryArea *page_start; - -int memory_lock(void) { - int_disable(); - return 0; -} - -int memory_unlock(void) { - int_enable(); - return 0; -} - -static int n_pages(const struct MemoryArea *m) { - return (m->len - sizeof(*m)) / sizeof(page); -} - -static void *page_at(int i) { - int cur_page = 0; - for (struct MemoryArea *m = page_start; m != NULL; m = m->next) { - int pages = n_pages(m); - if (i - cur_page < pages) { - page *page_array = (page *) (m + 1); - return page_array[i - cur_page]; - } - cur_page += pages; - } - return NULL; -} - -static int page_idx(page p) { - uintptr_t addr = (uintptr_t) p; - int cur_page = 0; - for (struct MemoryArea *m = page_start; m != NULL; m = m->next) { - if ((uintptr_t) m + m->len > addr) { - return cur_page + (addr - (uintptr_t) m) / sizeof(page); - } - cur_page += n_pages(m); - } - return -1; -} - -static inline bool bitmap_get(int i) { - return (bitmap[i / 32] >> i % 32) & 1; -} - -static inline void bitmap_set(int i, bool v) { - int idx = i / 32; - bitmap[idx] &= ~(1 << i % 32); - bitmap[idx] |= (v << i % 32); -} - -void *memory_alloc_page(int pages) { - if (pages < 1) return NULL; - - int n_contiguous = 0; - int free_region_start = 0; - bool first = true; - for (uint32_t i = page_free_start; i < page_count; i++) { - bool free = !bitmap_get(i); - - if (first) { - first = false; - page_free_start = i; - } - - if (free) { - if (n_contiguous == 0) free_region_start = i; - n_contiguous++; - if (n_contiguous == pages) { - for (int j = 0; j < pages; j++) - bitmap_set(free_region_start + j, true); - return page_at(free_region_start); - } - } else n_contiguous = 0; - } - - return NULL; -} - -int memory_free_page(void *ptr, int pages) { - int idx = page_idx(ptr); - if (idx == -1) return 1; - - if ((unsigned) idx < page_free_start) page_free_start = idx; - - for (int i = 0; i < pages; i++) - bitmap_set(idx + pages, false); - return 0; -} - -void memory_init(void) { - - debugk("Loading memory pages"); - - memory_lock(); - - bitmap = NULL; - total_memory = 0; - free_memory = 0; - page_count = 0; - page_free_start = 0; - page_start = NULL; - - kernel_start_addr = (uintptr_t) &kernel_start; - kernel_end_addr = (uintptr_t) &kernel_end; - - struct BootTag *tag; - if (!get_boot_tag(iD_MEMORYMAP, &tag)) { - panic("No multiboot memory map found"); - } - - uintptr_t end = (uintptr_t) tag->data.memory_map; - end += tag->size; - - struct MemoryArea *prev = NULL; - struct MemorySegment *segment = &tag->data.memory_map->entries[0]; - for(; (uintptr_t) segment < end; segment++) { - - if (segment->type != 1) continue; - if (segment->addr >= UINT32_MAX) continue; - if (segment->addr < kernel_start_addr) continue; - - uint32_t length; - if (segment->addr + segment->len > UINT32_MAX) { - length = UINT32_MAX - segment->addr; - } else { - length = segment->len; - } - - uintptr_t addr; - if (segment->addr < kernel_end_addr) { - addr = kernel_end_addr; - length -= addr - segment->addr; - } else { - addr = segment->addr; - } - - struct MemoryArea *current = (struct MemoryArea *) addr; - current->prev = prev; - current->next = NULL; - current->len = length; - - if (prev != NULL) { - prev->next = current; - } else { - page_start = current; - } - - page_count += n_pages(current); - total_memory += length; - - prev = current; - - } - - int bitmap_pages = page_count / 32 / sizeof(page) + 1; - bitmap = (uint32_t *) page_at(page_count - bitmap_pages); - page_count -= bitmap_pages; - memset(bitmap, 0, bitmap_pages * sizeof(page)); - free_memory = page_count * sizeof(page); - - memory_unlock(); - - succek("Memory loaded. %k total %k free", total_memory, free_memory); - -} - -uint32_t memory_total(void) { - return total_memory; -} - -uint32_t memory_free(void) { - return free_memory; -} - -uint32_t memory_used(void) { - return total_memory - free_memory; -} |