From 5a4db78897063e5b09a676b02fec3ba4a2965921 Mon Sep 17 00:00:00 2001 From: Marvin Borner Date: Fri, 25 Oct 2019 23:26:29 +0200 Subject: Rewrite of paging and alloc functions Still not working though :/ --- src/kernel/paging/paging.c | 274 +++++++++++++++++++-------------------------- 1 file changed, 118 insertions(+), 156 deletions(-) (limited to 'src/kernel/paging/paging.c') diff --git a/src/kernel/paging/paging.c b/src/kernel/paging/paging.c index 0b7428e..f1dc340 100644 --- a/src/kernel/paging/paging.c +++ b/src/kernel/paging/paging.c @@ -1,187 +1,149 @@ +#include #include "paging.h" -#include "kheap.h" #include "../system.h" -#include "../lib/lib.h" -#include "../io/io.h" - -page_directory_t *kernel_directory = 0; -page_directory_t *current_directory = 0; -uint32_t *frames; -uint32_t nframes; - -extern uint32_t placement_address; -extern heap_t *kheap; - -#define INDEX_FROM_BIT(a) (a/(8*4)) -#define OFFSET_FROM_BIT(a) (a%(8*4)) - -static void set_frame(uint32_t frame_addr) { - uint32_t frame = frame_addr / 0x1000; - uint32_t idx = INDEX_FROM_BIT(frame); - uint32_t off = OFFSET_FROM_BIT(frame); - frames[idx] |= (0x1 << off); -} - -static void clear_frame(uint32_t frame_addr) { - uint32_t frame = frame_addr / 0x1000; - uint32_t idx = INDEX_FROM_BIT(frame); - uint32_t off = OFFSET_FROM_BIT(frame); - frames[idx] &= ~(0x1 << off); -} - -/*static uint32_t test_frame(uint32_t frame_addr) { - uint32_t frame = frame_addr / 0x1000; - uint32_t idx = INDEX_FROM_BIT(frame); - uint32_t off = OFFSET_FROM_BIT(frame); - return (frames[idx] & (0x1 << off)); -}*/ - -static uint32_t first_frame() { - uint32_t i, j; - for (i = 0; i < INDEX_FROM_BIT(nframes); i++) { - if (frames[i] != 0xFFFFFFFF) { - for (j = 0; j < 32; j++) { - uint32_t toTest = 0x1 << j; - if (!(frames[i] & toTest)) { - return i * 4 * 8 + j; - } - } + +extern void *end; + +uint32_t page_directory[1024] __attribute__((aligned(4096))); +uint32_t page_tables[1024][1024] __attribute__((aligned(4096))); + +void paging_install() { + for (uint32_t i = 0; i < 1024; i++) { + for (uint32_t j = 0; j < 1024; j++) { + page_tables[i][j] = ((j * 0x1000) + (i * 0x400000)) | PT_RW; } } - return -1; -} - -void alloc_frame(page_t *page, int is_kernel, int is_writeable) { - if (page->frame != 0) { - return; - } else { - uint32_t idx = first_frame(); - if (idx == (uint32_t) -1) panic("No free frames!"); - set_frame(idx * 0x1000); - page->present = 1; - page->rw = (is_writeable == 1) ? 1 : 0; - page->user = (is_kernel == 1) ? 0 : 1; - page->frame = idx; - } -} -void free_frame(page_t *page) { - uint32_t frame; - if (!(frame = page->frame)) { - return; - } else { - clear_frame(frame); - page->frame = 0x0; + for (uint32_t i = 0; i < 1024; i++) { + page_directory[i] = ((uint32_t) page_tables[i]) | PD_RW | PD_PRESENT; } -} - -void initialise_paging() { - uint32_t mem_end_page = 0x1000000; - nframes = mem_end_page / 0x1000; - frames = (uint32_t *) kmalloc(INDEX_FROM_BIT(nframes)); - memory_set(frames, 0, INDEX_FROM_BIT(nframes)); - kernel_directory = (page_directory_t *) kmalloc_a(sizeof(page_directory_t)); - memory_set(kernel_directory, 0, sizeof(page_directory_t)); - kernel_directory->physicalAddr = (uint32_t) kernel_directory->tablesPhysical; + // TODO: Calculate max memory + paging_set_present(0, 0x1000000); - unsigned int i = 0; - for (i = KHEAP_START; i < KHEAP_START + KHEAP_INITIAL_SIZE; i += 0x1000) - get_page(i, 1, kernel_directory); + paging_set_used(0, ((uint32_t) end >> 12) + 1); - i = 0; - while (i < 0x400000) { - alloc_frame(get_page(i, 1, kernel_directory), 0, 0); - i += 0x1000; - } - - for (i = KHEAP_START; i < KHEAP_START + KHEAP_INITIAL_SIZE; i += 0x1000) - alloc_frame(get_page(i, 1, kernel_directory), 0, 0); + paging_enable(); +} - switch_page_directory(kernel_directory); - kheap = create_heap(KHEAP_START, KHEAP_START + KHEAP_INITIAL_SIZE, 0xCFFFF000, 0, 0); - current_directory = clone_directory(kernel_directory); - switch_page_directory(current_directory); - serial_write("Paging init successful!\n"); +int paging_enabled() { + uint32_t cr0; + asm volatile("mov %%cr0, %0": "=r"(cr0)); + return (cr0 | 0x80000000) == cr0; } -void disable_paging() { +void paging_disable() { uint32_t cr0; asm volatile("mov %%cr0, %0": "=r"(cr0)); cr0 &= 0x7fffffff; asm volatile("mov %0, %%cr0"::"r"(cr0)); } -void enable_paging() { - switch_page_directory(kernel_directory); - switch_page_directory(current_directory); -} - -void switch_page_directory(page_directory_t *dir) { - current_directory = dir; - asm volatile("mov %0, %%cr3"::"r"(dir->physicalAddr)); +void paging_enable() { + asm volatile("mov %0, %%cr3"::"r"(page_directory)); uint32_t cr0; asm volatile("mov %%cr0, %0": "=r"(cr0)); cr0 |= 0x80000000; asm volatile("mov %0, %%cr0"::"r"(cr0)); } -page_t *get_page(uint32_t address, int make, page_directory_t *dir) { - address /= 0x1000; - uint32_t table_idx = address / 1024; - - if (dir->tables[table_idx]) { - return &dir->tables[table_idx]->pages[address % 1024]; - } else if (make) { - uint32_t tmp; - dir->tables[table_idx] = (page_table_t *) kmalloc_ap(sizeof(page_table_t), &tmp); - memory_set(dir->tables[table_idx], 0, 0x1000); - dir->tablesPhysical[table_idx] = tmp | 0x7; - return &dir->tables[table_idx]->pages[address % 1024]; - } else { - return 0; +inline void invlpg(uint32_t addr) { + asm volatile("invlpg (%0)"::"r" (addr) : "memory"); +} + +void paging_map(uint32_t phy, uint32_t virt, uint16_t flags) { + uint32_t pdi = virt >> 22; + uint32_t pti = virt >> 12 & 0x03FF; + page_tables[pdi][pti] = phy | flags; + invlpg(virt); +} + +uint32_t paging_get_physical_addr(uint32_t virt) { + uint32_t pdi = virt >> 22; + uint32_t pti = (virt >> 12) & 0x03FF; + return page_tables[pdi][pti] & 0xFFFFF000; +} + +uint16_t paging_get_flags(uint32_t virt) { + uint32_t pdi = virt >> 22; + uint32_t pti = (virt >> 12) & 0x03FF; + return page_tables[pdi][pti] & 0xFFF; +} + +void paging_set_flag_up(uint32_t virt, uint32_t count, uint32_t flag) { + uint32_t page_n = virt / 4096; + for (uint32_t i = page_n; i < page_n + count; i++) { + page_tables[i / 1024][i % 1024] |= flag; + invlpg(i * 4096); + } +} + +void paging_set_flag_down(uint32_t virt, uint32_t count, uint32_t flag) { + uint32_t page_n = virt / 4096; + for (uint32_t i = page_n; i < page_n + count; i++) { + page_tables[i / 1024][i % 1024] &= ~flag; + invlpg(i * 4096); + } +} + +void paging_set_present(uint32_t virt, uint32_t count) { + paging_set_flag_up(virt, count, PT_PRESENT); +} + +void paging_set_absent(uint32_t virt, uint32_t count) { + paging_set_flag_down(virt, count, PT_PRESENT); +} + +void paging_set_used(uint32_t virt, uint32_t count) { + paging_set_flag_up(virt, count, PT_USED); +} + +void paging_set_free(uint32_t virt, uint32_t count) { + paging_set_flag_down(virt, count, PT_USED); +} + +void paging_set_user(uint32_t virt, uint32_t count) { + uint32_t page_n = virt / 4096; + for (uint32_t i = page_n; i < page_n + count; i += 1024) { + page_directory[i / 1024] |= PD_ALL_PRIV; } + paging_set_flag_up(virt, count, PT_ALL_PRIV); } -static page_table_t *clone_table(page_table_t *src, uint32_t *physAddr) { - page_table_t *table = (page_table_t *) kmalloc_ap(sizeof(page_table_t), physAddr); - memory_set(table, 0, sizeof(page_directory_t)); - - int i; - for (i = 0; i < 1024; i++) { - if (!src->pages[i].frame) - continue; - alloc_frame(&table->pages[i], 0, 0); - if (src->pages[i].present) table->pages[i].present = 1; - if (src->pages[i].rw) table->pages[i].rw = 1; - if (src->pages[i].user) table->pages[i].user = 1; - if (src->pages[i].accessed)table->pages[i].accessed = 1; - if (src->pages[i].dirty) table->pages[i].dirty = 1; - extern void copy_page_physical(int a, int b); - copy_page_physical(src->pages[i].frame * 0x1000, table->pages[i].frame * 0x1000); +uint32_t paging_find_pages(uint32_t count) { + uint32_t continous = 0; + uint32_t startDir = 0; + uint32_t startPage = 0; + for (uint32_t i = 0; i < 1024; i++) { + for (uint32_t j = 0; j < 1024; j++) { + if (!(page_tables[i][j] & PT_PRESENT) || (page_tables[i][j] & PT_USED)) { + continous = 0; + startDir = i; + startPage = j + 1; + } else { + if (++continous == count) + return (startDir * 0x400000) + (startPage * 0x1000); + } + } } - return table; -} - -page_directory_t *clone_directory(page_directory_t *src) { - uint32_t phys; - page_directory_t *dir = (page_directory_t *) kmalloc_ap(sizeof(page_directory_t), &phys); - memory_set(dir, 0, sizeof(page_directory_t)); - uint32_t offset = (uint32_t) dir->tablesPhysical - (uint32_t) dir; - dir->physicalAddr = phys + offset; - - for (int i = 0; i < 1024; i++) { - if (!src->tables[i]) - continue; - - if (kernel_directory->tables[i] == src->tables[i]) { - dir->tables[i] = src->tables[i]; - dir->tablesPhysical[i] = src->tablesPhysical[i]; - } else { - uint32_t phys; - dir->tables[i] = clone_table(src->tables[i], &phys); - dir->tablesPhysical[i] = phys | 0x07; + + panic("Out of memory!"); + return 0; +} + +uint32_t paging_alloc_pages(uint32_t count) { + uint32_t ptr = paging_find_pages(count); + paging_set_used(ptr, count); + return ptr; +} + +uint32_t paging_get_used_pages() { + uint32_t n = 0; + for (uint32_t i = 0; i < 1024; i++) { + for (uint32_t j = 0; j < 1024; j++) { + uint8_t flags = page_tables[i][j] & PT_USED; + if (flags == 1) n++; } } - return dir; + return n; 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