erm

Makefile

@@ -8,7 +8,7 @@ LDFLAGS = -ffreestanding -nostdlib
 LDLIBS = -lgcc
 LDFILE = -T linker.ld
 
-c_objects = kernel.o
+c_objects = kernel.o term.o
 asm_objects = boot.o
 
 ISODIR = isodir

gdt.c

@@ -0,0 +1,23 @@
+#include "gdt.c"
+
+void encodeGdtEntry(uint8_t *target, struct GDT source) {
+    // Check the limit to make sure that it can be encoded
+    if (source.limit > 0xFFFFF) {kerror("GDT cannot encode limits larger than 0xFFFFF");}
+ 
+    // Encode the limit
+    target[0] = source.limit & 0xFF;
+    target[1] = (source.limit >> 8) & 0xFF;
+    target[6] = (source.limit >> 16) & 0x0F;
+ 
+    // Encode the base
+    target[2] = source.base & 0xFF;
+    target[3] = (source.base >> 8) & 0xFF;
+    target[4] = (source.base >> 16) & 0xFF;
+    target[7] = (source.base >> 24) & 0xFF;
+ 
+    // Encode the access byte
+    target[5] = source.access_byte;
+ 
+    // Encode the flags
+    target[6] |= (source.flags << 4);
+}

gdt.h

@@ -0,0 +1,6 @@
+#ifndef GDT_K_H
+#define GDT_K_H
+
+void encodeGdtEntry(uint8_t *target, struct GDT source);
+
+#endif

kernel.c

@@ -2,6 +2,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include "multiboot.h"
+#include "term.h"
 /* Check if the compiler thinks you are targeting the wrong operating system. */
 #if defined(__linux__)
 #error "You are not using a cross-compiler, you will most certainly run into trouble"
@@ -12,107 +13,8 @@
 #error "This tutorial needs to be compiled with a ix86-elf compiler"
 #endif
 
-/* Hardware text mode color constants. */
+kVGATerm vgaterm;
-enum vga_color {
-	VGA_COLOR_BLACK = 0,
-	VGA_COLOR_BLUE = 1,
-	VGA_COLOR_GREEN = 2,
-	VGA_COLOR_CYAN = 3,
-	VGA_COLOR_RED = 4,
-	VGA_COLOR_MAGENTA = 5,
-	VGA_COLOR_BROWN = 6,
-	VGA_COLOR_LIGHT_GREY = 7,
-	VGA_COLOR_DARK_GREY = 8,
-	VGA_COLOR_LIGHT_BLUE = 9,
-	VGA_COLOR_LIGHT_GREEN = 10,
-	VGA_COLOR_LIGHT_CYAN = 11,
-	VGA_COLOR_LIGHT_RED = 12,
-	VGA_COLOR_LIGHT_MAGENTA = 13,
-	VGA_COLOR_LIGHT_BROWN = 14,
-	VGA_COLOR_WHITE = 15,
-};
 
-static inline uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg) {
-	return fg | bg << 4;
-}
- 
-static inline uint16_t vga_entry(unsigned char uc, uint8_t color) {
-	return (uint16_t) uc | (uint16_t) color << 8;
-}
- 
-size_t strlen(const char* str) {
-	size_t len = 0;
-	while (str[len])
-		len++;
-	return len;
-}
- 
-static const size_t VGA_WIDTH = 80;
-static const size_t VGA_HEIGHT = 25;
- 
-size_t terminal_row;
-size_t terminal_column;
-uint8_t terminal_color;
-uint16_t* terminal_buffer;
- 
-void terminal_initialize(void) {
-	terminal_row = 0;
-	terminal_column = 0;
-	terminal_color = vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
-	terminal_buffer = (uint16_t*) 0xB8000;
-	for (size_t y = 0; y < VGA_HEIGHT; y++) {
-		for (size_t x = 0; x < VGA_WIDTH; x++) {
-			const size_t index = y * VGA_WIDTH + x;
-			terminal_buffer[index] = vga_entry(' ', terminal_color);
-		}
-	}
-}
-
-void terminal_shiftup(void) {
-	for(size_t y = 0; y < VGA_HEIGHT-1; y++) {
-		for (size_t x = 0; x < VGA_WIDTH; x++) {
-			size_t index_current = y * VGA_WIDTH  + x;
-			size_t index_next = (y+1) * VGA_WIDTH  + x;
-			terminal_buffer[index_current] =  terminal_buffer[index_next];
-		}
-	}
-}
- 
-void terminal_setcolor(uint8_t color) {
-	terminal_color = color;
-}
- 
-void terminal_putentryat(char c, uint8_t color, size_t x, size_t y) {
-	const size_t index = y * VGA_WIDTH + x;
-	terminal_buffer[index] = vga_entry(c, color);
-}
- 
-void terminal_putchar(char c) {
-	if (c == '\n'){
-		terminal_row = terminal_row + 1;
-		terminal_column = 0;
-		return;
-	}
-	terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
-	terminal_column = terminal_column + 1;
-	if (terminal_column >= VGA_WIDTH) {
-		terminal_column = 0;
-		terminal_row = terminal_row + 1;
-	}
-	if (terminal_row >= VGA_HEIGHT) {
-	terminal_shiftup();
-	//terminal_row = 0;
-	}
-}
- 
-void terminal_write(const char* data, size_t size) {
-	for (size_t i = 0; i < size; i++)
-		terminal_putchar(data[i]);
-}
- 
-void terminal_writestring(const char* data) {
-	terminal_write(data, strlen(data));
-}
 
 void int_to_string(char * str, size_t strlen, size_t conv) {
 	char buffer[100];
@@ -137,12 +39,16 @@ void int_to_string(char * str, size_t strlen, size_t conv) {
 		j = j + 1;
 		}
 	}
+}
 
+void os_vga_writestring(char * data) {
+	terminal_writestring(&vgaterm, data);
 }
  
 void kernel_main(unsigned long addr) {
 	/* Initialize terminal interface */
-	terminal_initialize();
+	//kVGATerm vgaterm;
+	terminal_initialize(&vgaterm);
 	//uint32_t * flags = (uint32_t *) addr;
 
 	/* Newline support is left as an exercise. */
@@ -154,8 +60,8 @@ void kernel_main(unsigned long addr) {
 		x[i] = -1;
 	}
 	int_to_string(x, 50, mbi->mem_lower);
-	terminal_writestring(x);
+	os_vga_writestring(x);
-	terminal_writestring("\n");
+	os_vga_writestring("\n");
 
 	for (int i = 0; i < 50; i++) {
 		x[i] = -1;
@@ -163,12 +69,12 @@ void kernel_main(unsigned long addr) {
 
 	int_to_string(x, 50, mbi->mem_upper);
 
-	terminal_writestring(x);
+	os_vga_writestring(x);
-	terminal_writestring("\n");
+	os_vga_writestring("\n");
 
 
-	terminal_writestring("erm what da sigma\n");
+	os_vga_writestring("erm what da sigma\n");
-	terminal_writestring("Hello, kernel World!\n");
+	os_vga_writestring("Hello, kernel World!\n");
-	terminal_writestring("Hello, kernel World!\n");
+	os_vga_writestring("Hello, kernel World!\n");
-	terminal_writestring("Hello, kernel World!\n");
+	os_vga_writestring("Hello, kernel World!\n");
 }

multiboot.h

@@ -1,11 +1,127 @@
+/* multiboot.h - Multiboot header file. */
+/* Copyright (C) 1999,2003,2007,2008,2009,2010  Free Software Foundation, Inc.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to
+ *  deal in the Software without restriction, including without limitation the
+ *  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ *  sell copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in
+ *  all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL ANY
+ *  DEVELOPER OR DISTRIBUTOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+ *  IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
 #ifndef MULTIBOOT_HEADER
-#define MULTIBOOT_HEADER
+#define MULTIBOOT_HEADER 1
+
+/* How many bytes from the start of the file we search for the header. */
+#define MULTIBOOT_SEARCH                        8192
+#define MULTIBOOT_HEADER_ALIGN                  4
+
+/* The magic field should contain this. */
+#define MULTIBOOT_HEADER_MAGIC                  0x1BADB002
+
+/* This should be in %eax. */
+#define MULTIBOOT_BOOTLOADER_MAGIC              0x2BADB002
+
+/* Alignment of multiboot modules. */
+#define MULTIBOOT_MOD_ALIGN                     0x00001000
+
+/* Alignment of the multiboot info structure. */
+#define MULTIBOOT_INFO_ALIGN                    0x00000004
+
+/* Flags set in the ’flags’ member of the multiboot header. */
+
+/* Align all boot modules on i386 page (4KB) boundaries. */
+#define MULTIBOOT_PAGE_ALIGN                    0x00000001
+
+/* Must pass memory information to OS. */
+#define MULTIBOOT_MEMORY_INFO                   0x00000002
+
+/* Must pass video information to OS. */
+#define MULTIBOOT_VIDEO_MODE                    0x00000004
+
+/* This flag indicates the use of the address fields in the header. */
+#define MULTIBOOT_AOUT_KLUDGE                   0x00010000
+
+/* Flags to be set in the ’flags’ member of the multiboot info structure. */
+
+/* is there basic lower/upper memory information? */
+#define MULTIBOOT_INFO_MEMORY                   0x00000001
+/* is there a boot device set? */
+#define MULTIBOOT_INFO_BOOTDEV                  0x00000002
+/* is the command-line defined? */
+#define MULTIBOOT_INFO_CMDLINE                  0x00000004
+/* are there modules to do something with? */
+#define MULTIBOOT_INFO_MODS                     0x00000008
+
+/* These next two are mutually exclusive */
+
+/* is there a symbol table loaded? */
+#define MULTIBOOT_INFO_AOUT_SYMS                0x00000010
+/* is there an ELF section header table? */
+#define MULTIBOOT_INFO_ELF_SHDR                 0X00000020
+
+/* is there a full memory map? */
+#define MULTIBOOT_INFO_MEM_MAP                  0x00000040
+
+/* Is there drive info? */
+#define MULTIBOOT_INFO_DRIVE_INFO               0x00000080
+
+/* Is there a config table? */
+#define MULTIBOOT_INFO_CONFIG_TABLE             0x00000100
+
+/* Is there a boot loader name? */
+#define MULTIBOOT_INFO_BOOT_LOADER_NAME         0x00000200
+
+/* Is there a APM table? */
+#define MULTIBOOT_INFO_APM_TABLE                0x00000400
+
+/* Is there video information? */
+#define MULTIBOOT_INFO_VBE_INFO                 0x00000800
+#define MULTIBOOT_INFO_FRAMEBUFFER_INFO         0x00001000
+
+#ifndef ASM_FILE
 
 typedef unsigned char           multiboot_uint8_t;
 typedef unsigned short          multiboot_uint16_t;
 typedef unsigned int            multiboot_uint32_t;
 typedef unsigned long long      multiboot_uint64_t;
 
+struct multiboot_header
+{
+  /* Must be MULTIBOOT_MAGIC - see above. */
+  multiboot_uint32_t magic;
+
+  /* Feature flags. */
+  multiboot_uint32_t flags;
+
+  /* The above fields plus this one must equal 0 mod 2^32. */
+  multiboot_uint32_t checksum;
+
+  /* These are only valid if MULTIBOOT_AOUT_KLUDGE is set. */
+  multiboot_uint32_t header_addr;
+  multiboot_uint32_t load_addr;
+  multiboot_uint32_t load_end_addr;
+  multiboot_uint32_t bss_end_addr;
+  multiboot_uint32_t entry_addr;
+
+  /* These are only valid if MULTIBOOT_VIDEO_MODE is set. */
+  multiboot_uint32_t mode_type;
+  multiboot_uint32_t width;
+  multiboot_uint32_t height;
+  multiboot_uint32_t depth;
+};
+
+/* The symbol table for a.out. */
 struct multiboot_aout_symbol_table
 {
   multiboot_uint32_t tabsize;
@@ -15,6 +131,7 @@ struct multiboot_aout_symbol_table
 };
 typedef struct multiboot_aout_symbol_table multiboot_aout_symbol_table_t;
 
+/* The section header table for ELF. */
 struct multiboot_elf_section_header_table
 {
   multiboot_uint32_t num;
@@ -24,8 +141,6 @@ struct multiboot_elf_section_header_table
 };
 typedef struct multiboot_elf_section_header_table multiboot_elf_section_header_table_t;
 
-
-
 struct multiboot_info
 {
   /* Multiboot info version number */
@@ -105,4 +220,55 @@ struct multiboot_info
 };
 typedef struct multiboot_info multiboot_info_t;
 
-#endif
+struct multiboot_color
+{
+  multiboot_uint8_t red;
+  multiboot_uint8_t green;
+  multiboot_uint8_t blue;
+};
+
+struct multiboot_mmap_entry
+{
+  multiboot_uint32_t size;
+  multiboot_uint64_t addr;
+  multiboot_uint64_t len;
+#define MULTIBOOT_MEMORY_AVAILABLE              1
+#define MULTIBOOT_MEMORY_RESERVED               2
+#define MULTIBOOT_MEMORY_ACPI_RECLAIMABLE       3
+#define MULTIBOOT_MEMORY_NVS                    4
+#define MULTIBOOT_MEMORY_BADRAM                 5
+  multiboot_uint32_t type;
+} __attribute__((packed));
+typedef struct multiboot_mmap_entry multiboot_memory_map_t;
+
+struct multiboot_mod_list
+{
+  /* the memory used goes from bytes ’mod_start’ to ’mod_end-1’ inclusive */
+  multiboot_uint32_t mod_start;
+  multiboot_uint32_t mod_end;
+
+  /* Module command line */
+  multiboot_uint32_t cmdline;
+
+  /* padding to take it to 16 bytes (must be zero) */
+  multiboot_uint32_t pad;
+};
+typedef struct multiboot_mod_list multiboot_module_t;
+
+/* APM BIOS info. */
+struct multiboot_apm_info
+{
+  multiboot_uint16_t version;
+  multiboot_uint16_t cseg;
+  multiboot_uint32_t offset;
+  multiboot_uint16_t cseg_16;
+  multiboot_uint16_t dseg;
+  multiboot_uint16_t flags;
+  multiboot_uint16_t cseg_len;
+  multiboot_uint16_t cseg_16_len;
+  multiboot_uint16_t dseg_len;
+};
+
+#endif /* ! ASM_FILE */
+
+#endif /* ! MULTIBOOT_HEADER */

term.c

@@ -0,0 +1,80 @@
+#include "term.h"
+
+static inline uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg) {
+	return fg | bg << 4;
+}
+
+
+static inline uint16_t vga_entry(unsigned char uc, uint8_t color) {
+	return (uint16_t) uc | (uint16_t) color << 8;
+}
+
+
+void terminal_initialize(kVGATerm *term) {
+	term->terminal_row = 0;
+	term->terminal_column = 0;
+	term->terminal_color = vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
+	term->terminal_buffer = (uint16_t*) 0xB8000;
+
+	for (size_t y = 0; y < VGA_HEIGHT; y++) {
+		for (size_t x = 0; x < VGA_WIDTH; x++) {
+			const size_t index = y * VGA_WIDTH + x;
+			term->terminal_buffer[index] = vga_entry(' ', term->terminal_color);
+		}
+	}
+}
+
+void terminal_shiftup(kVGATerm *term){
+	for(size_t y = 0; y < VGA_HEIGHT-1; y++) {
+		for (size_t x = 0; x < VGA_WIDTH; x++) {
+			size_t index_current = y * VGA_WIDTH  + x;
+			size_t index_next = (y+1) * VGA_WIDTH  + x;
+			term->terminal_buffer[index_current] =  term->terminal_buffer[index_next];
+		}
+	}
+}
+
+void terminal_setcolor(kVGATerm *term, uint8_t color){
+	term->terminal_color = color;
+}
+
+void terminal_putentryat(kVGATerm *term, char c, uint8_t color, size_t x, size_t y){
+	size_t index = y * VGA_WIDTH + x;
+	term->terminal_buffer[index] = vga_entry(c, color);
+}
+
+void terminal_putchar(kVGATerm *term, char c){
+	if (c == '\n'){
+		term->terminal_row = term->terminal_row + 1;
+		term->terminal_column = 0;
+		return;
+	}
+	terminal_putentryat(term, c, term->terminal_color, term->terminal_column, term->terminal_row);
+	term->terminal_column = term->terminal_column + 1;
+	if (term->terminal_column >= VGA_WIDTH) {
+		term->terminal_column = 0;
+		term->terminal_row = term->terminal_row + 1;
+	}
+	if (term->terminal_row >= VGA_HEIGHT) {
+	terminal_shiftup(term);
+	//terminal_row = 0;
+	}
+}
+
+void terminal_write(kVGATerm *term, const char* data, size_t size) {
+	for (size_t i = 0; i < size; i++) {
+		terminal_putchar(term, data[i]);
+	}
+
+}
+
+void terminal_writestring(kVGATerm *term, const char* data) {
+	terminal_write(term, data, strlen(data));
+}
+
+size_t strlen(const char* str) {
+	size_t len = 0;
+	while (str[len])
+		len++;
+	return len;
+}

term.h

@@ -0,0 +1,62 @@
+#ifndef TERM_K_H
+#define TERM_K_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+static const size_t VGA_WIDTH = 80;
+static const size_t VGA_HEIGHT = 25;
+
+struct kVGATerm {
+	size_t terminal_row;
+	size_t terminal_column;
+	uint8_t terminal_color;
+	uint16_t* terminal_buffer;
+};
+typedef struct kVGATerm kVGATerm;
+void terminal_initialize(kVGATerm *term);
+
+void terminal_shiftup(kVGATerm *term);
+
+
+void terminal_setcolor(kVGATerm *term, uint8_t color);
+
+
+void terminal_putentryat(kVGATerm *term, char c, uint8_t color, size_t x, size_t y);
+
+
+void terminal_write(kVGATerm *term, const char* data, size_t size);
+
+void terminal_writestring(kVGATerm *term, const char * data);
+
+void terminal_putchar(kVGATerm *term, char c);
+
+enum vga_color {
+	VGA_COLOR_BLACK = 0,
+	VGA_COLOR_BLUE = 1,
+	VGA_COLOR_GREEN = 2,
+	VGA_COLOR_CYAN = 3,
+	VGA_COLOR_RED = 4,
+	VGA_COLOR_MAGENTA = 5,
+	VGA_COLOR_BROWN = 6,
+	VGA_COLOR_LIGHT_GREY = 7,
+	VGA_COLOR_DARK_GREY = 8,
+	VGA_COLOR_LIGHT_BLUE = 9,
+	VGA_COLOR_LIGHT_GREEN = 10,
+	VGA_COLOR_LIGHT_CYAN = 11,
+	VGA_COLOR_LIGHT_RED = 12,
+	VGA_COLOR_LIGHT_MAGENTA = 13,
+	VGA_COLOR_LIGHT_BROWN = 14,
+	VGA_COLOR_WHITE = 15,
+};
+
+static inline uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg);
+
+
+static inline uint16_t vga_entry(unsigned char uc, uint8_t color);
+
+size_t strlen(const char* str);
+
+
+#endif