diff options
Diffstat (limited to 'src/stem/mem/paging.c')
| -rw-r--r-- | src/stem/mem/paging.c | 171 |
1 files changed, 0 insertions, 171 deletions
diff --git a/src/stem/mem/paging.c b/src/stem/mem/paging.c deleted file mode 100644 index 27ce043..0000000 --- a/src/stem/mem/paging.c +++ /dev/null @@ -1,171 +0,0 @@ -#include "paging.h" -#include <bitset.h> -#include <stdlib.h> -#include <core/monitor.h> -#include "mem.h" -#include "seg.h" -#include <core/sys.h> -#include <task/task.h> - -static struct bitset frames; - -struct page_directory *kernel_pagedir, *current_pagedir; - -/* ACCESSOR FUNCTIONS FOR STATIC BITSET */ -uint32_t frame_alloc() { - uint32_t free = bitset_firstFree(&frames); - bitset_set(&frames, free); - return free; -} - -void frame_free(uint32_t id) { - bitset_clear(&frames, id); -} - - -void paging_init(size_t totalRam) { - uint32_t i; - - frames.size = totalRam / 0x1000; - frames.bits = kmalloc(INDEX_FROM_BIT(frames.size)); - - kernel_pagedir = kmalloc(sizeof(struct page_directory)); - kernel_pagedir->mappedSegs = 0; - kernel_pagedir->tablesPhysical = kmalloc_page(&kernel_pagedir->physicalAddr); - for (i = 0; i < 1024; i++) { - kernel_pagedir->tables[i] = 0; - kernel_pagedir->tablesPhysical[i] = 0; - } - - for (i = 0xE0000000; i < mem_placementAddr; i += 0x1000) { - page_map(pagedir_getPage(kernel_pagedir, i, 1), frame_alloc(), 0, 0); - } - for (i = 0; i < (mem_placementAddr - 0xE0000000) / 0x100000; i++) { - kernel_pagedir->tablesPhysical[i] = kernel_pagedir->tablesPhysical[i + 896]; - kernel_pagedir->tables[i] = kernel_pagedir->tables[i + 896]; - } - - monitor_write("Page dir is at: "); - monitor_writeHex(kernel_pagedir->physicalAddr); - pagedir_switch(kernel_pagedir); - monitor_write("\nPaging started\n"); -} - -void paging_cleanup() { - uint32_t i; - for (i = 0; i < (mem_placementAddr - 0xE0000000) / 0x100000; i++) { - kernel_pagedir->tablesPhysical[i] = 0; - kernel_pagedir->tables[i] = 0; - } - monitor_write("Pages cleaned up\n"); -} - -void pagedir_switch(struct page_directory *pd) { - current_pagedir = pd; - asm volatile("mov %0, %%cr3" : : "r"(pd->physicalAddr)); - uint32_t cr0; - asm volatile("mov %%cr0, %0" : "=r"(cr0)); - cr0 |= 0x80000000; - asm volatile("mov %0, %%cr0" : : "r"(cr0)); -} - -struct page_directory *pagedir_new() { - uint32_t i; - - struct page_directory *pd = kmalloc(sizeof(struct page_directory)); - pd->tablesPhysical = kmalloc_page(&pd->physicalAddr); - pd->mappedSegs = 0; - - for (i = 0; i < 1024; i++) { - pd->tables[i] = 0; pd->tablesPhysical[i] = 0; - } - - for (i = 896; i < 1024; i++) { - pd->tables[i] = kernel_pagedir->tables[i]; - pd->tablesPhysical[i] = kernel_pagedir->tablesPhysical[i]; - } - - return pd; -} - -void pagedir_delete(struct page_directory *pd) { - uint32_t i; - //Unmap segments - while (pd->mappedSegs != 0) seg_unmap(pd->mappedSegs); - //Cleanup page tables - for (i = 0; i < 896; i++) { - kfree_page(pd->tables[i]); - } - kfree_page(pd->tablesPhysical); - kfree(pd); -} - -uint32_t paging_fault(struct registers *regs) { - size_t addr; - struct segment_map *seg = 0; - asm volatile("mov %%cr2, %0" : "=r"(addr)); - - seg = current_pagedir->mappedSegs; - while (seg) { - if (seg->start <= addr && seg->start + seg->len > addr) break; - seg = seg->next; - } - - if (seg != 0) { - if (seg->seg->handle_fault(seg, addr, (regs->err_code & 0x2) && (regs->eip < 0xE0000000)) != 0) seg = 0; - } - - if (seg == 0) { - monitor_write("(paging.c:119) Unhandled Page Fault "); - if (regs->err_code & 0x1) monitor_write("present "); - if (regs->err_code & 0x2) monitor_write("write "); - if (regs->err_code & 0x4) monitor_write("user "); - if (regs->err_code & 0x8) monitor_write("rsvd "); - if (regs->err_code & 0x10) monitor_write("instructionfetch "); - monitor_write("@"); monitor_writeHex(addr); monitor_write("\n"); - return 1; - } - return 0; -} - -struct page *pagedir_getPage(struct page_directory *pd, uint32_t address, int make) { - address /= 0x1000; - uint32_t table_idx = address / 1024; - - if (pd->tables[table_idx]) { - return &pd->tables[table_idx]->pages[address % 1024]; - } else if (make) { - pd->tables[table_idx] = kmalloc_page(pd->tablesPhysical + table_idx); - if (table_idx >= 896) - tasking_updateKernelPagetable(table_idx, pd->tables[table_idx], pd->tablesPhysical[table_idx]); - memset((uint8_t*)pd->tables[table_idx], 0, 0x1000); - pd->tablesPhysical[table_idx] |= 0x07; - return &pd->tables[table_idx]->pages[address % 1024]; - } else { - return 0; - } -} - -void page_map(struct page *page, uint32_t frame, uint32_t user, uint32_t rw) { - if (page != 0 && page->frame == 0 && page->present == 0) { - page->present = 1; - page->rw = (rw ? 1 : 0); - page->user = (user ? 1 : 0); - page->frame = frame; - } -} - -void page_unmap(struct page *page) { - if (page != 0) { - page->frame = 0; - page->present = 0; - } -} - -void page_unmapFree(struct page *page) { - if (page != 0) { - if (page->frame != 0) frame_free(page->frame); - page->frame = 0; - page->present = 0; - } -} |