diff options
| -rw-r--r-- | kernel/include/mm/virtual_mm.h | 8 | ||||
| -rw-r--r-- | kernel/kernel/kernel.c | 2 | ||||
| -rw-r--r-- | kernel/mm/virtual_mm/virtual_mm.c | 45 |
3 files changed, 29 insertions, 26 deletions
diff --git a/kernel/include/mm/virtual_mm.h b/kernel/include/mm/virtual_mm.h index c0eb237..bb63f97 100644 --- a/kernel/include/mm/virtual_mm.h +++ b/kernel/include/mm/virtual_mm.h @@ -64,6 +64,9 @@ #define ADD_ATTRIB(entry, attribute) (*entry |= (attribute)) +#define VIRTUAL_ADDRESS(pd_index, pt_index) \ + (((pd_index) << 22) | ((pt_index) << 12)) + /* * Loads a given page directory into CR0 */ @@ -84,6 +87,9 @@ void virtual_mm_initialize(void); */ void virtual_mm_map_page(void *physical_address, void *virtual_address); -void virtual_mm_find_free_virtual_addresses(uint32_t n); +/* + * Find a virtual address with n consecutive free addresses. AWIUFHAILWFHIALW + */ +uint32_t virtual_mm_find_free_virtual_addresses(uint32_t n); #endif diff --git a/kernel/kernel/kernel.c b/kernel/kernel/kernel.c index 7a7f95f..e988857 100644 --- a/kernel/kernel/kernel.c +++ b/kernel/kernel/kernel.c @@ -49,7 +49,7 @@ kernel_main(uint32_t magic, multiboot_info_t *multiboot_info) printk("\nKernel", "Started."); // virtual_mm_map_page((void *) 0x0C00000, (void *) 0x3000); - virtual_mm_find_free_virtual_addresses(10000); + virtual_mm_find_free_virtual_addresses(3); exit(); halt(); /* If exit() fails (on real hardware) */ diff --git a/kernel/mm/virtual_mm/virtual_mm.c b/kernel/mm/virtual_mm/virtual_mm.c index 4153065..573767e 100644 --- a/kernel/mm/virtual_mm/virtual_mm.c +++ b/kernel/mm/virtual_mm/virtual_mm.c @@ -135,54 +135,51 @@ get_or_make_table(uint32_t *pd_entry) return table; } -ALWAYS_INLINE void +uint32_t virtual_mm_find_free_virtual_addresses(uint32_t n) { /* Skip the first page directory, we don't wanna touch the first 4MiB. */ - for (uint32_t i = 1; i < PAGE_DIRECTORY_SIZE; i++) { - uint32_t *pd_entry = ¤t_page_directory[i]; + for (uint32_t pd_index = 1; pd_index < PAGE_DIRECTORY_SIZE; pd_index++) { + uint32_t starting_pd_index = pd_index; + uint32_t *pd_entry = ¤t_page_directory[pd_index]; uint32_t *table = get_or_make_table(pd_entry); - for (uint32_t j = 0; j < PAGE_TABLE_SIZE; j++) { - uint32_t *pt_entry = &table[j]; + for (uint32_t starting_pt_index = 0; starting_pt_index < PAGE_TABLE_SIZE; + starting_pt_index++) { + uint32_t *pt_entry = &table[starting_pt_index]; if (PTE_IS_PRESENT(pt_entry)) continue; /* We found our starting pt_entry */ - printk("debug", "Starting: 0x%x", pt_entry); uint32_t count = 0; - for (uint32_t k = j; k <= PAGE_TABLE_SIZE; k++) { + for (uint32_t pt_index = starting_pt_index; pt_index <= PAGE_TABLE_SIZE; + pt_index++) { /* If we overflow, switch to the consecutive page directory entry */ - if (k == PAGE_TABLE_SIZE) { - if (++i == PAGE_DIRECTORY_SIZE) - ASSERT_NOT_REACHED(); /* Ran out of pd_entries */ - - pd_entry = ¤t_page_directory[i]; - printk("debug", "Switching pd_entry: 0x%x", pd_entry); + if (pt_index == PAGE_TABLE_SIZE) { + if (++pd_index == PAGE_DIRECTORY_SIZE) + return 0; /* Ran out of pd_entries */ + pd_entry = ¤t_page_directory[pd_index]; table = get_or_make_table(pd_entry); - k = 0; + pt_index = 0; } /* If page table entry is already used, break from the current loop */ - uint32_t *pt_entry = &table[k]; + uint32_t *pt_entry = &table[pt_index]; if (PTE_IS_PRESENT(pt_entry)) { /* Since we have some used address at some point between j and count, * we can't find n consecutive free addresses in between j and the * used block (j + count + 1) */ - j += count; + starting_pt_index += count; break; } - // printk("debug", "Found page: 0x%x", &table[k]); - count++; - if (count == n) { - /* TODO: Convert this into a virtual_address using the pd_index & - * pt_index */ - printk("debug", "Found starting page at: 0x%x", &table[j]); - return; - } + if (++count == n) + return VIRTUAL_ADDRESS(starting_pd_index, starting_pt_index); } } } + + ASSERT_NOT_REACHED(); + return 0; } |