Finally a working paging and heap, missing copyright headers added

README.md

@@ -7,7 +7,7 @@ Welcome to rockOS project, a hobby OS that aims to run rogue and nethack.
 - PIC initialization
 - PIT timer
 - Keyboard driver
-- a thing that is supposed to be paging
+- Paging and Kheap
 
 
 ## Usage
@@ -40,6 +40,8 @@ you can run qemu.sh to compile and open the OS on QEMU or iso.sh to just generat
 ## Acknowledgements
 - osdev.org community for huge documentation on OS Development
 - musl for libc implementation
+- James Molloy for his paging and kheap tutorial
+- Free Software Foundation for multiboot specification
 
 
 ## License

kernel/Makefile

@@ -30,6 +30,8 @@ LIBS:=$(LIBS) $(KERNEL_ARCH_LIBS)
 KERNEL_OBJS=\
 $(KERNEL_ARCH_OBJS) \
 rockos/kernel.o \
+rockos/data_struct/sorted_array.o \
+rockos/kheap.o \
 rockos/paging.o \
 rockos/keyboard.o \
 rockos/timer.o \

kernel/arch/i386/boot/gdt.c

@@ -37,6 +37,7 @@ void gdt_set_descriptor(uint8_t vector, uint32_t base, uint32_t limit, uint8_t a
 }
 
 void gdt_init(void) {
+    printf("Beginning gdt initialization.\n");
     gdt_set_descriptor(0, 0, 0, 0, 0);              // 0x0000 Null Descriptor
     gdt_set_descriptor(1, 0, 0xFFFFF, 0x9A, 0xC);   // 0x0008 Kernel Mode Code Segment
     gdt_set_descriptor(2, 0, 0xFFFFF, 0x92, 0xC);   // 0x0010 Kernel Mode Data Segment

kernel/arch/i386/boot/idt.c

@@ -96,6 +96,7 @@ void idt_set_descriptor(uint8_t vector, void (*isr)(void*), uint8_t flags) {
 }
 
 void idt_init(void) {
+    printf("Beginning IDT initialization.\n");
     idtptr.base = (uintptr_t)&idt[0];
     idtptr.limit = (uint16_t)sizeof(idt_entry_t) * IDT_MAX_DESCRIPTORS - 1;
 

kernel/arch/i386/vga/tty.c

@@ -1,3 +1,21 @@
+/**
+ *  TTY section header of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>

kernel/arch/i386/vga/vga.h

@@ -1,3 +1,21 @@
+/**
+ *  VGA section header of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 #ifndef ARCH_I386_VGA_H
 #define ARCH_I386_VGA_H
 

kernel/include/rockos/data_struct/sorted_array.h

@@ -0,0 +1,42 @@
+/**
+ *  Sorted array data structure header of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef _ROCKOS_ORDERED_ARRAY_H
+#define _ROCKOS_ORDERED_ARRAY_H
+
+#include <stdint.h>
+
+typedef char (*LessThan)(void*, void*);
+
+typedef struct {
+    void** data;
+    uint32_t size;
+    uint32_t max_size;
+    LessThan less_than;
+} SortedArray;
+
+char less_than(void*, void*);
+
+SortedArray SortedArrayCreate(uint32_t, LessThan);
+SortedArray SortedArrayPlace(void*, uint32_t, LessThan);
+void SortedArrayDestroy(SortedArray*);
+void SortedArrayInsert(void*, SortedArray*);
+void* SortedArraySearch(uint32_t, SortedArray*);
+void SortedArrayDelete(uint32_t, SortedArray*);
+
+#endif

kernel/include/rockos/kheap.h

@@ -0,0 +1,58 @@
+/**
+ *  KHeap section header of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef _ROCKOS_KHEAP_H
+#define _ROCKOS_KHEAP_H
+
+#include <stdint.h>
+#include <rockos/data_struct/sorted_array.h>
+
+#define KHEAP_START 0xC0000000
+#define KHEAP_INITIAL_SIZE 0x100000
+#define HEAP_INDEX_SIZE 0x20000
+#define HEAP_MAGIC 0x06163474
+#define HEAP_MIN_SIZE 0x70000
+
+typedef struct {
+   uint32_t magic;
+   uint8_t hole;
+   uint32_t size;
+} Header;
+
+typedef struct {
+   uint32_t magic;
+   Header* header;
+} Footer;
+
+typedef struct {
+   SortedArray index;
+   uint32_t addr_start;
+   uint32_t addr_end;
+   uint32_t addr_max;
+   uint8_t supervisor;
+   uint8_t readonly;
+} Heap;
+
+Heap* HeapCreate(uint32_t, uint32_t, uint32_t, uint8_t, uint8_t);
+void* alloc(uint32_t, uint8_t, Heap*);
+void free(void*, Heap*);
+uint32_t kmalloc_int(uint32_t, uint8_t, uint32_t*);
+uint32_t kmalloc(uint32_t);
+void kfree(void*);
+
+#endif

kernel/include/rockos/paging.h

@@ -16,15 +16,39 @@
  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-#include <stdint.h>
-#include <stddef.h>
-
 #ifndef _ROCKOS_PAGING_H
 #define _ROCKOS_PAGING_H
 
-#define PAGE_ENTRIES 1024
-#define PAGE_SIZE 4096
+#include <stdint.h>
 
-void alloc_pages(uint32_t*, size_t);
+typedef struct {
+   uint32_t present: 1;
+   uint32_t rw: 1;
+   uint32_t user: 1;
+   uint32_t accessed: 1;
+   uint32_t dirty: 1;
+   uint32_t unused: 7;
+   uint32_t frame: 20;
+} Page;
+
+typedef struct {
+   Page pages[1024];
+} PageTable;
+
+typedef struct {
+   PageTable* tables[1024];
+   uint32_t tablesPhys[1024];
+   uint32_t physAddr;
+} PageDirectory;
+
+void paging_init();
+void paging_switch_dir(PageDirectory*);
+Page* PageGet(uint32_t, int32_t, PageDirectory*);
+void FrameSet(uint32_t);
+void FrameClear(uint32_t);
+uint32_t FrameTest(uint32_t);
+uint32_t FrameFirst();
+void FrameFree(Page*);
+void FrameAlloc(Page*, char, char);
 
 #endif

kernel/include/rockos/rockos.h

@@ -0,0 +1,31 @@
+/**
+ *  Header of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+
+static inline void panic(char* str) {
+    printf("%s\n", str);
+    asm("cli;hlt");
+}
+
+static inline void assert(uint32_t val) {
+    if(!val) {
+        panic("ASSERTION FAILED!");
+    }
+}

kernel/rockos/data_struct/sorted_array.c

@@ -0,0 +1,87 @@
+/**
+ *  Sorted array data structure of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <rockos/data_struct/sorted_array.h>
+#include <rockos/rockos.h>
+#include <rockos/kheap.h>
+#include <string.h>
+
+char less_than(void* a, void* b) {
+    return a < b;
+}
+
+SortedArray SortedArrayCreate(uint32_t size, LessThan less) {
+    SortedArray myArray = {
+        .data = (void*)kmalloc(size * sizeof(void*)),
+        .size = 0,
+        .max_size = size,
+        .less_than = less,
+    };
+    memset(myArray.data, 0, size * sizeof(void*));
+    return myArray;
+}
+
+SortedArray SortedArrayPlace(void* address, uint32_t size, LessThan less) {
+    SortedArray myArray = {
+        .data = (void**)address,
+        .size = 0,
+        .max_size = size,
+        .less_than = less,
+    };
+    memset(myArray.data, 0, size * sizeof(void*));
+    return myArray;
+}
+
+void SortedArrayDestroy(SortedArray* myArray) {
+    kfree(myArray->data);
+}
+
+void SortedArrayInsert(void* element, SortedArray* myArray) {
+    assert((uint32_t)myArray->less_than);
+    uint32_t iter = 0;
+    while(iter < myArray->size && myArray->less_than(myArray->data[iter], element)) {
+        ++iter;
+    }
+    if(myArray->size == iter) {
+        myArray->data[myArray->size++] = element;
+    } else {
+        void* temp = myArray->data[iter];
+        myArray->data[iter] = element;
+        while(iter < myArray->size) {
+            ++iter;
+            void* temp2 = myArray->data[iter];
+            myArray->data[iter] = temp;
+            temp = temp2;
+        }
+        myArray->size++;
+    }
+}
+
+void* SortedArraySearch(uint32_t index, SortedArray* myArray) {
+    assert(index < myArray->size);
+    return myArray->data[index];
+}
+
+void SortedArrayDelete(uint32_t index, SortedArray* myArray) {
+    assert(index < myArray->size);
+    while (index < myArray->size) {
+        myArray->data[index] = myArray->data[index + 1];
+        ++index;
+    }
+    myArray->size--;
+}

kernel/rockos/kernel.c

@@ -1,23 +1,37 @@
-#include <stdio.h>
+/**
+ *  Entry point of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
 
+#include <stdio.h>
 #include <rockos/tty.h>
 #include <rockos/keyboard.h>
 #include <rockos/pic.h>
 #include <rockos/hal.h>
 #include <rockos/timer.h>
 #include <rockos/paging.h>
+#include <rockos/kheap.h>
 #include <rockos/multiboot.h>
+#include <rockos/rockos.h>
 #include <string.h>
 
 extern char _rockos_start, _rockos_end;
 
 static multiboot_info_t* multiboot_info;
 
-void panic(char* str) {
-    printf("%s\n", str);
-    asm("cli;hlt");
-}
-
 void bootloader_init(multiboot_info_t* mbd, unsigned int magic) {
     /* Make sure the magic number matches for memory mapping*/
     if(magic != MULTIBOOT_BOOTLOADER_MAGIC) {
@@ -65,13 +79,15 @@ void kernel_main() {
             //
         }
     }
-    uint32_t* pages;
-    alloc_pages(pages, 1);
-    printf("Page Start: %#08X\n", *pages);
-    alloc_pages(*pages, 8192);
-    for(int i = 0; i < 8192; ++i){
-        //printf("Page Start: %#08X\n", (uint32_t)(*pages + i));
-    }
+
+    uint32_t a = kmalloc(8);
+    uint32_t b = kmalloc(8);
+    uint32_t c = kmalloc(8);
+    printf("A: %#08X B: %#08X C: %#08X\n",a,b,c);
+    kfree(c);
+    kfree(b);
+    uint32_t d = kmalloc(8);
+    printf("D: %#08X\n", d);
 
     unsigned char key;
     for(;;) {

kernel/rockos/keyboard.c

@@ -1,3 +1,21 @@
+/**
+ *  Keyboard driver of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 #include <rockos/keyboard.h>
 #include <rockos/pic.h>
 #include <rockos/timer.h>

kernel/rockos/kheap.c

@@ -0,0 +1,292 @@
+/**
+ *  KHeap section of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <rockos/kheap.h>
+#include <rockos/paging.h>
+#include <rockos/rockos.h>
+#include <rockos/data_struct/sorted_array.h>
+
+extern char _rockos_end;
+uint32_t start_addr = (uint32_t)&_rockos_end;
+extern PageDirectory* kernel_dir;
+Heap* kheap = 0;
+
+static int32_t smallest_hole(uint32_t size, uint8_t aligned, Heap* heap) {
+    uint32_t i = 0;
+    while(i < heap->index.size) {
+        Header* header = (Header*)SortedArraySearch(i, &heap->index);
+        if(aligned) {
+            uint32_t location = (uint32_t)header;
+            uint32_t offset = 0;
+            if((location + sizeof(Header) & ~0xFFF) != 0) {
+                offset = 0x1000 - (location + sizeof(Header)) % 0x1000;
+            }
+            uint32_t hole_size = (uint32_t)header->size - offset;
+            if(hole_size >= (uint32_t)size) {
+                break;
+            }
+        } else if (header->size >= size) {
+            break;
+        }
+        i++;
+    }
+    if(i == heap->index.size) {
+        return -1;
+    }
+    return i;
+}
+
+static void expand(uint32_t size, Heap* heap) {
+    assert(size > heap->addr_end - heap->addr_start);
+    if((size & ~0xFFF) != 0) {
+        size &= ~0xFFF;
+        size += 0x1000;
+    }
+    assert(heap->addr_start + size <= heap->addr_max);
+    uint32_t size_old = heap->addr_end - heap->addr_start;
+    for(uint32_t i = size_old; i < size; i+= 0x1000) {
+        FrameAlloc( PageGet(heap->addr_start + i, 1, kernel_dir), heap->supervisor, heap->readonly );
+    }
+    heap->addr_end = heap->addr_start + size;
+}
+
+static uint32_t shrink(uint32_t size, Heap* heap) {
+    assert(size < heap->addr_end - heap->addr_start);
+    if(size & 0x1000) {
+        size &= 0x1000;
+        size += 0x1000;
+    }
+    if(size < HEAP_MIN_SIZE) {
+        size = HEAP_MIN_SIZE;
+    }
+
+    uint32_t size_old = heap->addr_end - heap->addr_start;
+    for(uint32_t i = size_old - 0x1000; size < i; i -= 0x1000) {
+        FrameFree(PageGet(heap->addr_start + i, 0, kernel_dir));
+    }
+
+    heap->addr_end = heap->addr_start + size;
+    return size;
+}
+
+void* alloc(uint32_t size, uint8_t aligned, Heap* heap) {
+    uint32_t size_new = size + sizeof(Header) + sizeof(Footer);
+    int32_t iter = smallest_hole(size_new, aligned, heap);
+    if(iter == -1) {
+        uint32_t len_old = heap->addr_end - heap->addr_start;
+        uint32_t end_old_addr = heap->addr_end;
+        expand(len_old + size_new, heap);
+        uint32_t len_new = heap->addr_end - heap->addr_start;
+        iter = 0;
+        uint32_t idx = -1;
+        uint32_t val = 0;
+        while((uint32_t)iter < heap->index.size) {
+            uint32_t temp = (uint32_t)SortedArraySearch(iter, &heap->index);
+            if (temp > val) {
+                val = temp;
+                idx = iter;
+            }
+            ++iter;
+        }
+
+        if(idx == -1) {
+            Header* header = (Header*)end_old_addr;
+            header->magic = HEAP_MAGIC;
+            header->size = len_new - len_old;
+            header->hole = 1;
+            Footer* footer = (Footer*)(end_old_addr + header->size - sizeof(Footer));
+            footer->magic = HEAP_MAGIC;
+            footer->header = header;
+            SortedArrayInsert((void*)header, &heap->index);
+        } else {
+            Header* header = SortedArraySearch(idx, &heap->index);
+            header->size += len_new - len_old;
+            Footer* footer = (Footer*)((uint32_t)header + header->size - sizeof(Footer));
+            footer->magic = HEAP_MAGIC;
+            footer->header = header;
+        }
+        return alloc(size, aligned, heap);
+    }
+
+    Header* hole_header_old = (Header*)SortedArraySearch(iter, &heap->index);
+    uint32_t hole_pos_old = (uint32_t)hole_header_old;
+    uint32_t hole_size_old = hole_header_old->size;
+
+    if(hole_size_old - size_new < sizeof(Header) + sizeof(Footer)) {
+        size += hole_size_old - size_new;
+        size_new = hole_size_old;
+    }
+
+    if(aligned && (hole_pos_old & ~0xFFF)) {
+        uint32_t location_new = hole_pos_old + 0x1000 - (hole_pos_old & 0xFFF) - sizeof(Header);
+        Header* hole_header = (Header*) hole_pos_old;
+        hole_header->size = 0x1000 - (hole_pos_old & 0xFFF) - sizeof(Header);
+        hole_header->magic = HEAP_MAGIC;
+        hole_header->hole = 1;
+        Footer* hole_footer = (Footer*)((uint32_t)location_new - sizeof(Footer));
+        hole_footer->magic = HEAP_MAGIC;
+        hole_footer->header = hole_header;
+        hole_pos_old = location_new;
+        hole_size_old -= hole_header->size;
+    } else {
+        SortedArrayDelete(iter, &heap->index);
+    }
+
+    Header* block_header = (Header*)hole_pos_old;
+    block_header->magic = HEAP_MAGIC;
+    block_header->hole = 0;
+    block_header->size = size_new;
+    Footer* block_footer = (Footer*)(hole_pos_old + sizeof(Header) + size);
+    block_footer->magic = HEAP_MAGIC;
+    block_footer->header = block_header;
+
+    if(hole_size_old - size_new) {
+        Header* hole_header = (Header*)(hole_pos_old + sizeof(Header) + size + sizeof(Footer));
+        hole_header->magic = HEAP_MAGIC;
+        hole_header->hole = 1;
+        hole_header->size = hole_size_old - size_new;
+        Footer* hole_footer = (Footer*)((uint32_t)hole_header + hole_size_old - size_new - sizeof(Footer));
+        if ((uint32_t)hole_footer < heap->addr_end) {
+            hole_footer->magic = HEAP_MAGIC;
+            hole_footer->header = hole_header;
+        }
+        SortedArrayInsert((void*)hole_header, &heap->index);
+    }
+    return (void*)((uint32_t)block_header + sizeof(Header));
+}
+
+void free(void* pointer, Heap* heap) {
+    if(pointer == 0)
+        return;
+    
+    Header* header = (Header*)((uint32_t)pointer - sizeof(Header));
+    Footer* footer = (Footer*)((uint32_t)header + header->size - sizeof(Footer));
+
+    assert(header->magic == HEAP_MAGIC);
+    assert(footer->magic == HEAP_MAGIC);
+
+    header->hole = 1;
+    char add = 1;
+
+    Footer* temp_footer = (Footer*)((uint32_t)header - sizeof(Footer));
+    if(temp_footer->magic == HEAP_MAGIC && temp_footer->header->hole) {
+        uint32_t cache_size = header->size;
+        header = temp_footer->header;
+        footer->header = header;
+        header->size += cache_size;
+        add = 0;
+    }
+
+    Header* temp_header = (Header*)((uint32_t)footer + sizeof(footer));
+    if(temp_header->magic == HEAP_MAGIC && temp_header->hole) {
+        header->size += temp_header->size;
+        temp_footer = (Footer*)((uint32_t)temp_header + temp_header->size - sizeof(Footer));
+        footer = temp_footer;
+        uint32_t iter = 0;
+        while((iter < heap->index.size) && (SortedArraySearch(iter, &heap->index) != (void*)temp_header)) {
+            ++iter;
+        }
+        assert(iter < heap->index.size);
+        SortedArrayDelete(iter, &heap->index);
+    }
+
+    if((uint32_t)footer + sizeof(Footer) == heap->addr_end) {
+        uint32_t len_old = heap->addr_end - heap->addr_start;
+        uint32_t len_new = shrink((uint32_t)header - heap->addr_start, heap);
+        if(header->size - (len_old - len_new) > 0) {
+            header->size -= len_old - len_new;
+            footer = (Footer*)((uint32_t)header + header->size - sizeof(Footer));
+            footer->magic = HEAP_MAGIC;
+            footer->header = header;
+        } else {
+            uint32_t iter = 0;
+            while((iter < heap->index.size) && (SortedArraySearch(iter, &heap->index) != (void*)temp_header)) {
+                ++iter;
+            }
+            if(iter < heap->index.size) {
+                SortedArrayDelete(iter, &heap->index);
+            }
+        }
+    }
+
+    if(add) {
+        SortedArrayInsert((void*)header, &heap->index);
+    }
+}
+
+uint32_t kmalloc_int(uint32_t size, uint8_t aligned, uint32_t* phys_addr) {
+    if(kheap) {
+        void* addr = alloc(size, aligned, kheap);
+        if (phys_addr) {
+            Page* page = PageGet((uint32_t)addr, 0, kernel_dir);
+            *phys_addr = (page->frame * 0x1000) + ((uint32_t)addr & 0xFFF);
+        }
+        return (uint32_t)addr;
+    }
+    if(aligned && (start_addr & 0xFFF)) {
+        start_addr &= ~0xFFF;
+        start_addr += 0x1000;
+    }
+    if(phys_addr) {
+        *phys_addr = start_addr;
+    }
+    uint32_t temp = start_addr;
+    start_addr += size;
+    return temp;
+}
+
+uint32_t kmalloc(uint32_t size) {
+    return kmalloc_int(size, 0, 0);
+}
+
+void kfree(void* pointer) {
+    free(pointer, kheap);
+}
+
+static char HeaderLessThan(void* a, void* b) {
+    return ((Header*)a)->size < ((Header*)b)->size;
+}
+
+Heap* HeapCreate(uint32_t start, uint32_t end, uint32_t max, uint8_t supervisor, uint8_t readonly) {
+    Heap* heap = (Heap*)kmalloc(sizeof(Heap));
+
+    assert(start % 0x1000 == 0);
+    assert(end % 0x1000 == 0);
+
+    heap->index = SortedArrayPlace((void*)start, HEAP_INDEX_SIZE, &HeaderLessThan);
+    start += sizeof(void*) * HEAP_INDEX_SIZE;
+
+    if(start & ~0xFFF) {
+        start &= ~0xFFF;
+        start += 0x1000;
+    }
+
+    heap->addr_start = start;
+    heap->addr_end = end;
+    heap->addr_max = max;
+    heap->supervisor = supervisor;
+    heap->readonly = readonly;
+
+    Header* hole = (Header*)start;
+    hole->size = end - start;
+    hole->magic = HEAP_MAGIC;
+    hole->hole = 1;
+    SortedArrayInsert((void*)hole, &heap->index);
+
+    return heap;
+}

kernel/rockos/paging.c

@@ -1,76 +1,142 @@
+/**
+ *  Paging section of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 #include <rockos/paging.h>
-#include <stdint.h>
-#include <stddef.h>
-#include <stdio.h>
+#include <rockos/kheap.h>
+#include <rockos/rockos.h>
+#include <string.h>
 
-void load_page_dir(uint32_t* page_dir) {
-    asm volatile (
-        "mov %%eax, %%cr3"
-        :
-        : "a"(page_dir)
-        : "memory"
-    );
+#define INDEX_FROM_BIT(x) (x/(8*4))
+#define OFFSET_FROM_BIT(x) (x%(8*4))
+
+PageDirectory* kernel_dir = 0;
+PageDirectory* current_dir = 0;
+
+uint32_t* frames;
+uint32_t nframes;
+
+extern uint32_t start_addr;
+extern Heap* kheap;
+
+void FrameSet(uint32_t frame_addr) {
+    uint32_t frame = frame_addr / 0x1000;
+    frames[INDEX_FROM_BIT(frame)] |= (1 << OFFSET_FROM_BIT(frame));
 }
 
-void enable_paging() {
-    asm volatile (
-        "mov %cr0, %eax\n"
-        "or $0x80000000, %eax\n"
-        "mov %eax, %cr0"
-    );
+void FrameClear(uint32_t frame_addr) {
+    uint32_t frame = frame_addr / 0x1000;
+    frames[INDEX_FROM_BIT(frame)] &= ~(1 << OFFSET_FROM_BIT(frame));
 }
 
-extern char _rockos_end;
-static uint32_t* page_dir __attribute__((packed));
+uint32_t FrameTest(uint32_t frame_addr) {
+    uint32_t frame = frame_addr / 0x1000;
+    return (frames[INDEX_FROM_BIT(frame)] & (1 << OFFSET_FROM_BIT(frame)));
+}
+
+uint32_t FrameFirst() {
+    for(uint32_t i = 0; i < INDEX_FROM_BIT(nframes); ++i) {
+        if(frames[i] != 0xFFFFFFFF) {
+            for(uint32_t j = 0; j < 32; ++j) {
+                uint32_t test = 1 << j;
+                if(!(frames[i]&test)) {
+                    return i*4*8 + j;
+                }
+            }
+        }
+    }
+    return 0;
+}
+
+void FrameAlloc(Page* page, char kernel, char writeable) {
+    if (page->frame) {
+        return;
+    }
+    uint32_t i = FrameFirst();
+    if(i == (uint32_t)-1) {
+        panic("NO FREE FRAMES LEFT!");
+    }
+    FrameSet(i * 0x1000);
+    page->present = 1;
+    page->rw = writeable;
+    page->user = !kernel;
+    page->frame = i;
+}
+
+void FrameFree(Page* page) {
+    uint32_t frame;
+    if(!(frame = page->frame)) {
+        return;
+    }
+    FrameClear(frame);
+    page->frame = 0;
+}
+
+Page* PageGet(uint32_t addr, int32_t make, PageDirectory* dir) {
+    addr /= 0x1000;
+    uint32_t table_i = addr / 1024;
+    if(dir->tables[table_i]) {
+        return &dir->tables[table_i]->pages[addr%1024];
+    }
+
+    if(make) {
+        uint32_t temp;
+        dir->tables[table_i] = (PageTable*)kmalloc_int(sizeof(PageTable), 1, &temp);
+        memset(dir->tables[table_i], 0, 0x1000);
+        dir->tablesPhys[table_i] = temp | 0x7;
+        return &dir->tables[table_i]->pages[addr%1024];
+    }
+
+    return 0;
+}
+
+void paging_switch_dir(PageDirectory* dir) {
+    current_dir = dir;
+    asm volatile("mov %0, %%cr3":: "r"(&dir->tablesPhys));
+    uint32_t cr0;
+    asm volatile("mov %%cr0, %0": "=r"(cr0));
+    cr0 |= 0x80000000;
+    asm volatile("mov %0, %%cr0":: "r"(cr0));
+}
 
 void paging_init() {
-    page_dir = (uint32_t*)(((uint32_t)&_rockos_end & ~0xFFF) + 0x1000);
-    for(int i = 0; i < PAGE_ENTRIES; i++) {
-        // Supervisor: only kernel-mode can access
-        // Write Enabled: Can be both read and written to
-        // Not Present: Page table not present
-        *(page_dir + i) = 0x00000002;
+    printf("Initializing paging.\n");
+    uint32_t page_end_mem = 0x1000000;
+    nframes = page_end_mem / 0x1000;
+
+    frames = (uint32_t*)kmalloc(INDEX_FROM_BIT(nframes));
+    memset(frames, 0, INDEX_FROM_BIT(nframes));
+
+    kernel_dir = (PageDirectory*)kmalloc_int(sizeof(PageDirectory), 1, 0);
+    memset(kernel_dir, 0, sizeof(PageDirectory));
+    current_dir = kernel_dir;
+
+    for(uint32_t i = KHEAP_START; i < KHEAP_START + KHEAP_INITIAL_SIZE; i += 0x1000) {
+        PageGet(i, 1, kernel_dir);
     }
 
-    uint32_t* firstPageTable __attribute__((packed)) = (uint32_t*)(((uint32_t)page_dir & ~0xFFF) + 0x1000);
-    for(unsigned int i = 0; i < PAGE_ENTRIES; i++) {
-        // As the address is page aligned, it will leave 12 bits zeroed,
-        // which are used by the attributes.
-        firstPageTable[i] = (i*0x1000) | 0x003; // attr: supervisor, r/w, present, 9th bit set
+    for(uint32_t i = 0; i < start_addr + 0x1000; i += 0x1000) {
+        FrameAlloc(PageGet(i, 1, kernel_dir), 0, 0);
     }
 
-    page_dir[0] = (uint32_t)firstPageTable | 0x003; //attr: supervisor, r/w, present
-    load_page_dir(page_dir);
-    enable_paging();
+    for(uint32_t i = KHEAP_START; i < KHEAP_START + KHEAP_INITIAL_SIZE; i += 0x1000) {
+        FrameAlloc(PageGet(i, 1, kernel_dir), 0, 0);
     }
 
-void alloc_pages(uint32_t* pages, size_t size) {
-    for(size_t i = 0; i < size;) {
-        for(size_t j = 0; j < PAGE_ENTRIES && i < size; ++j) {
-            printf("oklahoma %#08X\n", page_dir[j]);
-            if((page_dir[j] & 3) == 3) {
-                uint32_t* pageTable __attribute__((packed)) = page_dir[j] & ~0xFFF;
-                for(int k = 0; k < PAGE_ENTRIES && i < size; ++k) {
-                    if((pageTable[k] & 3) == 3 && (pageTable[k] & 0x100) != 0x100) {
-                        pageTable[k] |= 0x100;
-                        pages[i] = ((uint32_t)pageTable & ~0xFFF) | (pageTable[k] >> 12);
-                        printf("connecticut %#08X\n", pages[i]);
-                        ++i;
-                    }
-                }
-            } else {
-                printf("aa %#08X\n", (page_dir[j-1] & ~0xFFF) + 0x4000);
-                uint32_t* newPageTable __attribute__((packed)) = (page_dir[j-1] & ~0xFFF) + 0x4000;
-                printf("alabama %#08X, %#08X\n", newPageTable[0], (page_dir[j-1] & ~0xFFF) + 0x4000);
-                for(unsigned int l = 0; l < PAGE_ENTRIES; l++) {
-                    // As the address is page aligned, it will leave 12 bits zeroed,
-                    // which are used by the attributes.
-                    newPageTable[l] = (l*0x1000) | 0x003; // attr: supervisor, r/w, present, 9th bit set
-                }
-                page_dir[j] = (uint32_t)newPageTable | 0x003;
-                printf("NewPageTable: %#08X\n", page_dir[j]);
-                --j;
-            }
-        }
-    }
+    paging_switch_dir(kernel_dir);
+    kheap = HeapCreate(KHEAP_START, KHEAP_START + KHEAP_INITIAL_SIZE, 0xCFFFF000, 0, 0);
 }

kernel/rockos/timer.c

@@ -1,3 +1,21 @@
+/**
+ *  PIT section of rockOS
+ *  Copyright (C) 2022 Furkan Mudanyali
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, _either version 3 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 #include <rockos/timer.h>
 #include <rockos/hal.h>
 #include <rockos/pic.h>