work on page loading

kernel/memory/pageframealloc.cc

@@ -88,8 +88,8 @@ void PageFrameAllocator::stats(){
         //if(bitmap[i/8] & (1<<i%8))
             pages_available++;
     }
-    for(uint64_t i=0; i < 0x2000000/4096/8; i++){
-        if(i%64 == 0){
+    for(uint64_t i=0; i < 0x8000000/4096/8; i+=4){
+        if(i%(64*4) == 0){
             DBG << endl << hex << i * 8 * 4096 << " " << flush;
             int x,y;
             dout.getPos(x,y);
@@ -104,9 +104,10 @@ void PageFrameAllocator::stats(){
             DBG << '.';
     }
     DBG << "\npages available: " << dec << pages_available << endl;
+
 }
 
-PageFrame* PageFrameAllocator::alloc(bool kernel){
+void* PageFrameAllocator::alloc(bool kernel){
     uintptr_t search_start;
     uintptr_t search_end;
     if(kernel){
@@ -131,7 +132,7 @@ PageFrame* PageFrameAllocator::alloc(bool kernel){
         return 0;
 
     mark_pageframes(free_pageframe*4096, free_pageframe*4096, false);
-    return &PageFrames[free_pageframe];
+    return (void*)(free_pageframe*4096);
 }
 
 void PageFrameAllocator::free(PageFrame* frame){

kernel/memory/pageframealloc.h

@@ -12,7 +12,7 @@ namespace PageFrameAllocator {
 
     void init ();
     void stats ();
-    PageFrame* alloc(bool kernel);
+    void* alloc(bool kernel);
     void free (PageFrame *frame);
     void free (uintptr_t addr);
 }

kernel/memory/pagetable.cc

@@ -4,12 +4,11 @@
 void load_cr3( void* cr3_value ) {
     asm volatile("mov %0, %%cr3" :: "r"((uint64_t)cr3_value) : "memory");
 }
-void create_basic_page_table(uintptr_t base){
+void create_basic_page_table(four_lvl_paging_t* table){
     //pagedirectory_entry_t *l4 = (pagedirectory_entry_t *)(base + (0 * 4096));
     //pagedirectory_entry_t *l3 = (pagedirectory_entry_t *)(base + (1 * 4096));
     //pagedirectory_entry_t *l2 = (pagedirectory_entry_t *)(base + (2 * 4096));
     //pagetable_entry_t     *l1 = (pagetable_entry_t *)    (base + (7 * 4096));
-    four_lvl_paging_t* table = (four_lvl_paging_t*)base;
 
     table->l4.entries[0] = {
         .present = 1,
@@ -25,7 +24,19 @@ void create_basic_page_table(uintptr_t base){
         .address = (uintptr_t)&(table->l2) >> 12,
     };
 
-    for(uint32_t i=0; i<sizeof(table->l1)/sizeof(table->l1[0]); i++){
+    //kernel memory
+    //for(uintptr_t i=0; i<0x4000000/(2*1024*1024); i++){
+    //    table->l2.entries[i] = {
+    //        .present = 1,
+    //        .write = 1,
+    //        .user = 1,
+    //        .pat = 1,   //2MB pages
+    //        .address = i,
+    //    };
+    //}
+
+    //kernel memory
+    for(uint32_t i=0; i<KERNEL_MEMORY_BORDER/4096/512; i++){
         table->l2.entries[i] = {
             .present = 1,
             .write = 1,
@@ -34,8 +45,7 @@ void create_basic_page_table(uintptr_t base){
         };
     }
 
-    //kernel memory
-    for(uintptr_t i=0; i<0x4000000/4096; i++){
+    for(uintptr_t i=0; i<KERNEL_MEMORY_BORDER/4096; i++){
         table->l1[i/512].entries[i%512] = {
             .present = 1,
             .write = 1,
@@ -78,13 +88,14 @@ void create_basic_page_table(uintptr_t base){
         .address = 0xFEE00,
     };
 
-
     //unmap 0 page
     table->l1[0].entries[0].present = 0;
-
-    ////map ioapic
-    //uintptr_t ioapic_page = 0xfec00000 >> 12;
-    //table->l1[ioapic_page/512].entries[ioapic_page%512].address = ioapic_page;
-    //table->l1[ioapic_page/512].entries[ioapic_page%512].present = 1;
-    //table->l1[ioapic_page/512].entries[ioapic_page%512].write = 1;
 }
+
+void map_pageframe(four_lvl_paging_t* table, uintptr_t phys, uintptr_t virt){
+    uint64_t pagefr_nr = phys / 4096;
+
+    table->l1[pagefr_nr/512].entries[pagefr_nr%512].address = virt >> 12;
+    table->l1[pagefr_nr/512].entries[pagefr_nr%512].present = 1;
+}
+

kernel/memory/pagetable.h

@@ -3,6 +3,8 @@
 
 #include "../types.h"
 
+#define KERNEL_MEMORY_BORDER 0x4000000
+
 typedef struct {
     uint8_t present:1 = 0;
     uint8_t write:1 = 0;
@@ -39,14 +41,15 @@ typedef struct {
     alignas(4096) pagetable_t l4;
     alignas(4096) pagetable_t l3;
     alignas(4096) pagetable_t l2;
-    alignas(4096) pagetable_t l1[64];
+    alignas(4096) pagetable_t l1[KERNEL_MEMORY_BORDER/4096/512];
     alignas(4096) pagetable_t l2_apic;
     alignas(4096) pagetable_t ioapic;
     alignas(4096) pagetable_t lapic;
 } four_lvl_paging_t;
 
-void create_basic_page_table(uintptr_t base);
-void load_cr3( void* cr3_value );
+void create_basic_page_table(four_lvl_paging_t* table);
+void load_cr3(void* cr3_value);
+void map_pageframe(four_lvl_paging_t* table, uintptr_t phys, uintptr_t virt);
 
 //typedef struct {
 // same