Merge branch 'development'

Author: Louis Jenkins

MoltarOS.sublime-workspace

@@ -12,13 +12,14 @@ The below depicts an early "schedule" or rather a path I will be taking in terms
 - [x] Interrupts (IRQ + ISR)
 - [x] VGA Display Driver
 - [x] Keyboard Driver
-- [ ] Memory Management (Physical + Virtual)
-- [ ] Interactive Shell
+- [x] Memory Management (Physical + Virtual)
+- [x] Higher Half Kernel
 - [ ] File System
+- [ ] Process Creation and Managements
 - [ ] Multitasking and Scheduling
 - [ ] Networking
-- [ ] Process Creation and Managements
 - [ ] ELF Binary Support
+- [ ] Interactive Shell
 - [ ] Graphical User Interfaces
 
 #Progress Update & Changelog
@@ -47,4 +48,11 @@ a significant amount of work and should be pushed to master.
 
 Lastly, I also added a nice logger macro, `KLOG`, and panic macro, `KPANIC`.
 
-![Screenshot](/ram_and_kbd.PNG)
+![Screenshot](/ram_and_kbd.PNG)
+
+
+## Version .002
+
+It is FINALLY here! I have implemented not only memory management (paging and a heap allocator), but even converted to a higher-half kernel approach, which was also easier, surprisingly, than a normal identity-mapped system. I've also fixed up the tests and their output format to better portray the significance of the initialization of the kernel thus far. I am very satisfied with what I have done, but unfortunately, I have to attend to another project for the time being.
+
+![Screenshot](/all_tests_and_heap.PNG)

README.md

@@ -1,5 +1,5 @@
 # Include directories
-INCLUDE := kernel x86 drivers
+INCLUDE := kernel x86 drivers mm
 
 # List of all headers from the included directories
 HEADERS := $(shell find $(INCLUDE) -type f -name \*.h)

all_tests_and_heap.PNG

@@ -34,7 +34,7 @@ static void update_cursor();
 	Initializes the buffer's attributes above to their proper values, should be called before kmain().
 */
 void vga_init() {
-	buf = (uint16_t *) 0xB8000;
+	buf = (uint16_t *) 0xC00B8000;
 	x = y = 0;
 	color = make_color(COLOR_LIGHT_GREY, COLOR_BLACK);
 

src/kernel/Makefile

@@ -22,7 +22,7 @@ static struct {
     // Note: All the above is packed into 1 byte. :)
 
     // Bit array of currently pressed keys
-    uint8_t pressed[BIT_ARRAY_SZ(256)];
+    uint8_t pressed[BITMAP_SIZE(256)];
 } KBD_STATE;
 
 #endif /* endif MOLTAROS_KBD_HAL_H */

src/kernel/drivers/vga.c

@@ -4,6 +4,17 @@
 #include <stdio.h>
 #include <stdbool.h>
 
+#define MAX(x, y) ((x) > (y) ? (x) : (y))
+
+#define MIN(x, y) ((x) > (y) ? (y) : (x))
+
+#define HALT \
+do { \
+	asm volatile ("cli"); \
+	while (true) \
+		asm volatile ("hlt"); \
+} while (0) 
+
 // Ceiling of integer divison.
 #define CEILING(x,y) (((x) + (y) - 1) / (y))
 

src/kernel/include/drivers/kbd_hal.h

@@ -13,12 +13,17 @@
 // Kernel Panic which will just print error message and spin
 #define KPANIC(format, ...) \
 do { \
-	printf("[%s:%s:%s] PANIC: \"" format "\"\n", __FILE__, __FUNCTION__, STRINGIFY(__LINE__),  ##__VA_ARGS__); \
+	printf("\n[%s:%s:%s] PANIC: \"" format "\"\n", __FILE__, __FUNCTION__, STRINGIFY(__LINE__),  ##__VA_ARGS__); \
 	asm volatile ("cli"); \
 	while (true) \
 		asm volatile ("hlt"); \
 } while (0)
 
+#define KFRAME \
+do {\
+	printf("FUNCTION: %s, FP: %x, CALLER FP: %x\n", __FUNCTION__, __builtin_frame_address(0), __builtin_frame_address(1)); \
+} while (0)
+
 #define STRINGIFY(x) _STRINGIFY(x)
 #define _STRINGIFY(x) #x
 

src/kernel/include/helpers.h

@@ -0,0 +1,15 @@
+#ifndef MOLTAROS_MEM_H
+#define MOLTAROS_MEM_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+extern uint32_t PAGE_SIZE;
+
+void mem_init();
+
+void *kmalloc(size_t sz);
+
+void kfree(void *ptr);
+
+#endif /* endif MOLTAROS_MEM_H */

src/kernel/include/kernel/logger.h

@@ -63,13 +63,12 @@ struct multiboot_mmap {
 
 static bool multiboot_RAM(struct multiboot_info *mbinfo, uint32_t *start, uint32_t *end) {
 	bool found = false;
-	printf("Flags: %d\n", mbinfo->flags);
 	// Check if there is a memory mapping available
 	if (mbinfo->flags & (1 << 6)) {
-		KLOG("MMAP Entries: %d", mbinfo->mmap_length / 24);
-		struct multiboot_mmap *mmap = mbinfo->mmap_addr;
-		while(mmap < mbinfo->mmap_addr + mbinfo->mmap_length) {
-			KLOG("MMAP Entry: {Type: %s, Start: %x, Length: %x}", mmap->type == MULTIBOOT_MMAP_RAM ? "RAM" : "RESERVED", mmap->start_low, mmap->length_low);
+		// KLOG("MMAP Entries: %d", mbinfo->mmap_length / 24);
+		struct multiboot_mmap *mmap = (struct multiboot_mmap *) (0xC0000000 + mbinfo->mmap_addr);
+		while((uint32_t) mmap - 0xC0000000 < (mbinfo->mmap_addr + mbinfo->mmap_length)) {
+			// KLOG("MMAP Entry: {Type: %s, Start: %x, Length: %x}", mmap->type == MULTIBOOT_MMAP_RAM ? "RAM" : "RESERVED", mmap->start_low, mmap->length_low);
 			// Jackpot... (The OS is 32-bit, so there is no upper currently.)
 			if (mmap->type == MULTIBOOT_MMAP_RAM) {
 				*start = mmap->start_low;