Directory listing, kheap and pmm

Kheap and pmm, plus we can list directories now! As well, some bugfixes with the ext2 filesystem inode read.

.gitignore

@@ -0,0 +1,2 @@
+ext2.img
+commit.txt

Makefile

@@ -21,6 +21,10 @@ MKDIR= mkdir -p
 CP = cp -f
 DEFINES=
 
+# qemu
+QEMU= qemu-system-i386
+QEMU_FLAGS= -cdrom out/SimpleOS.iso -drive file=ext2.img,format=raw
+
 # assembler flags
 ASM_FLAGS = -f elf32
 # compiler flags
@@ -36,16 +40,19 @@ TARGET_ISO=$(OUT)/SimpleOS.iso
 ISO_DIR=$(OUT)/isodir
 
 OBJECTS=$(ASM_OBJ)/entry.o $(ASM_OBJ)/load_gdt.o\
-		$(ASM_OBJ)/load_idt.o $(ASM_OBJ)/exception.o $(ASM_OBJ)/irq.o\
+		$(ASM_OBJ)/load_idt.o $(ASM_OBJ)/exception.o $(ASM_OBJ)/irq.o $(ASM_OBJ)/load_tss.o\
 		$(OBJ)/io_ports.o $(OBJ)/vga.o\
 		$(OBJ)/string.o $(OBJ)/console.o\
 		$(OBJ)/gdt.o $(OBJ)/idt.o $(OBJ)/isr.o $(OBJ)/8259_pic.o\
 		$(OBJ)/keyboard.o $(OBJ)/mouse.o\
 		$(OBJ)/kernel.o\
 		$(OBJ)/gui.o\
 		$(OBJ)/hd.o\
-		$(OBJ)/ext2.o
-
+		$(OBJ)/ext2.o\
+		$(OBJ)/ide.o\
+		$(OBJ)/tss.o\
+		$(OBJ)/kheap.o\
+		$(OBJ)/pmm.o
 
 all: $(OBJECTS)
 	@printf "[ linking... ]\n"
@@ -84,6 +91,11 @@ $(ASM_OBJ)/irq.o : $(ASM_SRC)/irq.asm
 	$(ASM) $(ASM_FLAGS) $(ASM_SRC)/irq.asm -o $(ASM_OBJ)/irq.o
 	@printf "\n"
 
+$(ASM_OBJ)/load_tss.o : $(ASM_SRC)/load_tss.asm
+	@printf "[ $(ASM_SRC)/irq.asm ]\n"
+	$(ASM) $(ASM_FLAGS) $(ASM_SRC)/load_tss.asm -o $(ASM_OBJ)/load_tss.o
+	@printf "\n"
+
 $(OBJ)/io_ports.o : $(SRC)/io_ports.c
 	@printf "[ $(SRC)/io_ports.c ]\n"
 	$(CC) $(CC_FLAGS) -c $(SRC)/io_ports.c -o $(OBJ)/io_ports.o
@@ -154,7 +166,28 @@ $(OBJ)/ext2.o : $(SRC)/ext2.c
 	$(CC) $(CC_FLAGS) -c $(SRC)/ext2.c -o $(OBJ)/ext2.o
 	@printf "\n"
 
+$(OBJ)/ide.o : $(SRC)/ide.c
+	@printf "[ $(SRC)/ide.c ]\n"
+	$(CC) $(CC_FLAGS) -c $(SRC)/ide.c -o $(OBJ)/ide.o
+	@printf "\n"
+
+$(OBJ)/tss.o : $(SRC)/tss.c
+	@printf "[ $(SRC)/tss.c ]\n"
+	$(CC) $(CC_FLAGS) -c $(SRC)/tss.c -o $(OBJ)/tss.o
+	@printf "\n"
+
+$(OBJ)/kheap.o : $(SRC)/kheap.c
+	@printf "[ $(SRC)/kheap.c ]\n"
+	$(CC) $(CC_FLAGS) -c $(SRC)/kheap.c -o $(OBJ)/kheap.o
+	@printf "\n"
+
+$(OBJ)/pmm.o : $(SRC)/pmm.c
+	@printf "[ $(SRC)/pmm.c ]\n"
+	$(CC) $(CC_FLAGS) -c $(SRC)/pmm.c -o $(OBJ)/pmm.o
+	@printf "\n"
 
+run:
+	$(QEMU) $(QEMU_FLAGS)
 
 clean:
 	rm -f $(OBJ)/*.o

config/grub.cfg

@@ -1,7 +1,3 @@
-set timeout=0
-set default=0
-
 menuentry "SimpleOS" {
 	multiboot /boot/SimpleOS.bin
-	boot
 }

include/ext2.h

@@ -63,6 +63,16 @@ typedef struct ext2_inode
     unsigned char os_specific[12];
 } ext2_inode;
 
+typedef struct ext2_dirent
+{
+	uint32 inode;
+	uint32 dirent_size;
+	uint32 name_len;
+	uint32 prev_name_len;
+	uint32 type;
+	char* name;
+} ext2_dirent;
+
 ext2_superblock sb;
 ext2_bgdt bgdt;
 

include/kernel.h

@@ -15,6 +15,38 @@ extern uint8 __kernel_rodata_section_end;
 extern uint8 __kernel_bss_section_start;
 extern uint8 __kernel_bss_section_end;
 
-#endif
 
+typedef struct {
+    struct {
+        uint32 k_start_addr;
+        uint32 k_end_addr;
+        uint32 k_len;
+        uint32 text_start_addr;
+        uint32 text_end_addr;
+        uint32 text_len;
+        uint32 data_start_addr;
+        uint32 data_end_addr;
+        uint32 data_len;
+        uint32 rodata_start_addr;
+        uint32 rodata_end_addr;
+        uint32 rodata_len;
+        uint32 bss_start_addr;
+        uint32 bss_end_addr;
+        uint32 bss_len;
+    } kernel;
+
+    struct {
+        uint32 total_memory;
+    } system;
+
+    struct {
+        uint32 start_addr;
+        uint32 end_addr;
+        uint32 size;
+    } available;
+} KERNEL_MEMORY_MAP;
+
+extern KERNEL_MEMORY_MAP g_kmap;
+
+#endif
 

include/kheap.h

@@ -0,0 +1,55 @@
+#ifndef KHEAP_H
+#define KHEAP_H
+
+#include "types.h"
+
+// a singly linked list heap block
+typedef struct _kheap_block {
+    struct {
+        uint32 size;  // memory size
+        uint8 is_free; // block is free or not
+    } metadata;
+    struct _kheap_block *next; 
+    void *data;  // data pointer
+} __attribute__((packed)) KHEAP_BLOCK;
+
+/**
+ * initialize heap and set total memory size
+*/
+int kheap_init(void *start_addr, void *end_addr);
+
+/**
+ * increase the heap memory by size & get its address
+*/
+void *kbrk(int size);
+
+/**
+ * print list of allocated blocks
+*/
+void kheap_print_blocks();
+
+/**
+ * allocate given size if list is null
+ * otherwise try some memory allocation algorithm like best fit etc
+ * to find best block to allocate
+ * # Need to work on internal/external segmentaion problem
+*/
+void *kmalloc(int size);
+
+/**
+ * allocate memory n * size & zeroing out
+*/
+void *kcalloc(int n, int size);
+
+/**
+ * allocate a new block of memory
+ * copy previous block data & set free the previous block
+*/
+void *krealloc(void *ptr, int size);
+
+/**
+ * set free the block
+*/
+void kfree(void *addr);
+
+#endif

include/multiboot.h

@@ -8,44 +8,112 @@ Licensed under MIT ( https://github.com/xing1357/SimpleOS/blob/main/LICENSE )
 
 #include "types.h"
 
-#define MULTIBOOT_FLAG_MEM     0x001
-#define MULTIBOOT_FLAG_DEVICE  0x002
-#define MULTIBOOT_FLAG_CMDLINE 0x004
-#define MULTIBOOT_FLAG_MODS    0x008
-#define MULTIBOOT_FLAG_AOUT    0x010
-#define MULTIBOOT_FLAG_ELF     0x020
-#define MULTIBOOT_FLAG_MMAP    0x040
-#define MULTIBOOT_FLAG_CONFIG  0x080
-#define MULTIBOOT_FLAG_LOADER  0x100
-#define MULTIBOOT_FLAG_APM     0x200
-#define MULTIBOOT_FLAG_VBE     0x400
-
-struct multiboot
-{
+#define MULTIBOOT_MAGIC_HEADER      0x1BADB002
+#define MULTIBOOT_BOOTLOADER_MAGIC  0x2BADB002
+
+/* The Multiboot header. */
+typedef struct {
+    uint32 magic;
     uint32 flags;
-    uint32 mem_lower;
-    uint32 mem_upper;
-    uint32 boot_device;
-    uint32 cmdline;
-    uint32 mods_count;
-    uint32 mods_addr;
+    uint32 checksum;
+    uint32 header_addr;
+    uint32 load_addr;
+    uint32 load_end_addr;
+    uint32 bss_end_addr;
+    uint32 entry_addr;
+} MULTIBOOT_HEADER;
+
+/* The symbol table for a.out. */
+typedef struct {
+    uint32 tabsize;
+    uint32 strsize;
+    uint32 addr;
+    uint32 reserved;
+} AOUT_SYMBOL_TABLE;
+
+/* The section header table for ELF. */
+typedef struct {
     uint32 num;
     uint32 size;
     uint32 addr;
     uint32 shndx;
+} ELF_SECTION_HEADER_TABLE;
+
+typedef struct {
+    /* required, defined in entry.asm */
+    uint32 flags;
+
+    /* available low-high memory from BIOS, present if flags[0] is set(MEMINFO in entry.asm) */
+    uint32 mem_low;
+    uint32 mem_high;
+
+    /* "root" partition, present if flags[1] is set(BOOTDEVICE in entry.asm) */
+    uint32 boot_device;
+
+    /* kernel command line, present if flags[2] is set(CMDLINE in entry.asm) */
+    uint32 cmdline;
+
+    /* no of modules loaded, present if flags[3] is set(MODULECOUNT in entry.asm) */
+    uint32 modules_count;
+    uint32 modules_addr;
+
+    /* symbol table info, present if flags[4] & flags[5] is set(SYMT in entry.asm) */
+    union {
+        AOUT_SYMBOL_TABLE aout_sym;
+        ELF_SECTION_HEADER_TABLE elf_sec;
+    } u;
+
+    /* memory mapping, present if flags[6] is set(MEMMAP in entry.asm) */
     uint32 mmap_length;
+    uint32 mmap_addr;
+
+    /* drive info, present if flags[7] is set(DRIVE in entry.asm) */
     uint32 drives_length;
     uint32 drives_addr;
+
+    /* ROM configuration table, present if flags[8] is set(CONFIGT in entry.asm) */
     uint32 config_table;
+
+    /* boot loader name, present if flags[9] is set(BOOTLDNAME in entry.asm) */
     uint32 boot_loader_name;
+
+    /* Advanced Power Management(APM) table, present if flags[10] is set(APMT in entry.asm) */
     uint32 apm_table;
+
+    /* video info, present if flags[11] is set(VIDEO in entry.asm) */
     uint32 vbe_control_info;
     uint32 vbe_mode_info;
-    uint32 vbe_mode;
-    uint32 vbe_interface_seg;
-    uint32 vbe_interface_len;
-} __attribute__((packed));
+    uint16 vbe_mode;
+    uint16 vbe_interface_seg;
+    uint16 vbe_interface_off;
+    uint16 vbe_interface_len;
+
+    /* video framebufer info, present if flags[12] is set(VIDEO_FRAMEBUF in entry.asm)  */
+    uint64 framebuffer_addr;
+    uint32 framebuffer_pitch;
+    uint32 framebuffer_width;
+    uint32 framebuffer_height;
+    uint8 framebuffer_bpp;
+    uint8 framebuffer_type;  // indexed = 0, RGB = 1, EGA = 2
+
+} MULTIBOOT_INFO;
 
-typedef struct multiboot_header multiboot_header_t;
+
+typedef enum {
+    MULTIBOOT_MEMORY_AVAILABLE = 1,
+    MULTIBOOT_MEMORY_RESERVED,
+    MULTIBOOT_MEMORY_ACPI_RECLAIMABLE,
+    MULTIBOOT_MEMORY_NVS,
+    MULTIBOOT_MEMORY_BADRAM
+} MULTIBOOT_MEMORY_TYPE;
+
+typedef struct {
+    uint32 size;
+    uint32 addr_low;
+    uint32 addr_high;
+    uint32 len_low;
+    uint32 len_high;
+    MULTIBOOT_MEMORY_TYPE type;
+} MULTIBOOT_MEMORY_MAP;
 
 #endif