OS now allocs memory for called files. Slightly improved screen.h

Makefile

@@ -8,7 +8,6 @@ CFLAGS = -ffreestanding -m32 -Iinclude -Wall -Wextra
 SRC = ./src
 BUILD = ./build
 C_FILES = calc
-# C_FILES = $(shell find $(SRC) -name "*.c" -exec basename -s ".c" {} \;)
 
 .PHONY: os clean run
 
@@ -45,13 +44,13 @@ kernel: $(SRC)/kernel.c $(SRC)/entry.asm
 	@$(AS) -felf32 -o $(BUILD)/entry.o $(SRC)/entry.asm
 	@echo "Compiling $(SRC)/kernel.c..."
 	@$(CC) $(CFLAGS) -o $(BUILD)/kernel.o -c $(SRC)/kernel.c
-	@$(LD) -T $(SRC)/kernel.ld --oformat binary -o $(BUILD)/kernel.bin $(BUILD)/*.o
+	@$(LD) -T$(SRC)/kernel.ld --oformat binary -o $(BUILD)/kernel.bin $(BUILD)/*.o
 	@rm $(BUILD)/*.o
 
 $(C_FILES):
 	@echo "Compiling $(SRC)/$@.c..."
 	@$(CC) $(CFLAGS) -o $(BUILD)/$@.o -c $(SRC)/$@.c
-	@$(LD) -T $(SRC)/$@.ld --oformat binary -o $(BUILD)/$@.bin $(BUILD)/$@.o
+	@$(LD) -T$(SRC)/$@.ld --oformat binary -o $(BUILD)/$@.bin $(BUILD)/$@.o
 	@rm $(BUILD)/$@.o
 
 # Run QEMU

README.md

@@ -16,6 +16,7 @@ Since there's always more to do, here are the [todos](todo.txt).
 - Disk I/O
 - Font support (funky format)
 - 1920x1080 Resolution, 32bpp
+- Physical memory manager
 
 ## Building & Running
 If you want to try kern for some reason, you can.
@@ -52,7 +53,7 @@ Disk R/W: \
 _These images may be outdated, Idk_
 
 ## Known issues
-- Idk, they're probably just unknown ;)
+- If you run kernel.bin from shell, it will clear the memory map so when you load anything it will override the kernel code
 
 ## [Old Version](https://github.com/Tom-on64/old-kern)
 

include/graphics.h

@@ -18,6 +18,8 @@
 #define rgb(r,g,b) ( ((r) << 16 | (g) << 8 | (b)) & 0x00ffffff )
 
 void drawPixel(int32_t x, int32_t y, uint32_t color) {
+    uint32_t* vidmem = *(uint32_t**)(MODE_INFO_BLOCK + 40);
+    
     uint32_t offset = (y * WIDTH) + x;
     vidmem[offset] = color;
 }
@@ -94,6 +96,8 @@ void drawCircle(int32_t x, int32_t y, uint16_t radius, uint32_t color) {
 
 // Recursive (may need large stack)
 void boundaryFill(int32_t x, int32_t y, uint32_t fillColor, uint32_t boundaryColor) {
+    uint32_t* vidmem = *(uint32_t**)(MODE_INFO_BLOCK + 40);
+
     uint32_t offset = y * WIDTH + x;
 
     if (vidmem[offset] != fillColor && vidmem[offset] != boundaryColor) {

include/physicalMemManager.h

@@ -2,6 +2,7 @@
 #define PHYSICAL_MEM_MANAGER_H
 
 #include "string.h"
+#include "stdint.h"
 
 #define BLOCK_SIZE 4096 // 4kB
 #define BLOCKS_PER_BYTE 8

include/screen.h

@@ -14,19 +14,13 @@ struct cursor_s {
     uint32_t y;
 };
 
-static char* font;
-uint32_t* vidmem;
-uint16_t bytesPerScanline;
+static char* font = (char*)0x6000;
 
 static struct cursor_s cursor = { 0, 0 };
 
-void setupScreen() {
-    vidmem = *(uint32_t**)(MODE_INFO_BLOCK + 40); // Vidmem pointer location
-    bytesPerScanline = *(uint16_t*)(MODE_INFO_BLOCK + 16); // Bytes per scanline location
-}
-
 // TODO: Probably make the font bigger in a better way, but this works for now
 void putcAt(unsigned char c, uint32_t x, uint32_t y) {
+    uint32_t* vidmem = *(uint32_t**)(MODE_INFO_BLOCK + 40);
     uint32_t offset = (WIDTH * y * 16 + x * 8) * 2;
 
     char* bitmap = &font[((c % 128) - 1) * 16];
@@ -73,6 +67,8 @@ void print(const char* str) {
 }
 
 void clear() {
+    uint32_t* vidmem = *(uint32_t**)(MODE_INFO_BLOCK + 40);
+
     size_t i = 0;
     while (i < WIDTH*HEIGHT) {
         vidmem[i] = BG_COLOR; // #1f2937
@@ -83,8 +79,4 @@ void clear() {
     cursor.y = 0;
 }
 
-void loadFont(char* address) {
-    font = address;
-}
-
 #endif

notes.txt

@@ -1,8 +1,8 @@
 --- Memory Map ---
-0x1000 - Kernel
-0x5000 - VBE Mode Info Block
-0x6000 - Font
-0x7000 - Filetable (0x7c00 - Bootloader)
-...
-0x10000 - Loaded programs
+0x1000  - Kernel
+0x5000  - VBE Mode Info Block
+0x6000  - Font
+0x7000  - Filetable (0x7c00 - Bootloader)
+0x8500  - ACPI Memory map
+0x30000 - Memory manager memmap
 

src/calc.c

@@ -1,15 +1,11 @@
 #include "stdint.h"
+#include "screen.h"
 
+__attribute__ ((section ("entry")))
 void main() {
-    uint32_t wait = 0xfffffff;
+    uint32_t wait = 0xffffffff;
 
-    uint32_t* vidmem = *(uint32_t**)(0x5000 + 40);
-
-    for (uint32_t x = 200; x < 400; x++) {
-        for (uint32_t y = 200; y < 400; y++) {
-            vidmem[y * 1920 + x] = 0x00ffffff;
-        }
-    }
+    putc('a');
     
     while (wait--);
 

src/calc.ld

@@ -1,5 +1,6 @@
 SECTIONS {
-    .text 0x10000 : {
+    .text : {
+        *(entry); 
         *(.text*);
     }
     .data : {

src/entry.asm

@@ -11,6 +11,7 @@
 _start:
     pop ax
     mov [driveNum], al
+
     call main
     
     ; Exit QEMU

src/kernel.c

@@ -19,6 +19,7 @@ uint32_t memmapAddr = 0x30000;
 void printFiletable(char* ft);
 void printPhysicalMemmap();
 
+__attribute__ ((section ("entry"))) // Make sure that main() is at the start of kernel.bin
 void main() {
     // Interrupts
     setupIdt();
@@ -49,8 +50,7 @@ void main() {
     // Screen setup
     // TODO: Find font in filetable
     diskRead(36, 4, (char*)0x6000); // Read font from disk
-    setupScreen();
-    loadFont((char*)0x6000);
+    // loadFont((char*)0x6000);
 
     clear();
     print("kern.\n\n");
@@ -229,27 +229,52 @@ void main() {
                     uint8_t size = *ft++;
                     found++; // Set found to 1
 
-                    char buf[size * 512];
-                    diskRead(sector, size, buf);
-
                     char* fileType = strchr(filename, '.') + 1;
 
+                    uint32_t neededBlocks = (size * 512) / BLOCK_SIZE + 1;
+
+                    /* Debug printing
+                    print("Allocating ");
+                    print(itoa(neededBlocks, 10));
+                    print(" Block");
+                    if (neededBlocks > 1) putc('s');
+                    */
+
+                    char* address = allocBlocks(neededBlocks);
+
+                    if (address == NULL) {
+                        print("\nNot enough memory to allocate!\n");
+                        break;
+                    }
+
+                    /* Debug printing
+                    print("\nAllocated to address 0x");
+                    print(itoa((uint32_t)address, 16));
+                    print("!\n");
+                    */
+
+                    diskRead(sector, size, address);
+
                     if (strcmp(fileType, "bin") == 0) {
-                        memcopy(buf, (char*)0x10000, size * 512);
                         clear(); 
-                        ((void(*)(void))0x10000)(); // Call program
+                        ((void(*)(void))address)(); // Call program
                         clear();
                     } else if (strcmp(fileType, "tab") == 0) {
-                        printFiletable(buf);
+                        printFiletable(address);
                     } else {
                         for (size_t i = 0; i < size * 512; i++) {
-                            if (buf[i] != '\0') {
-                                putc(buf[i]);
+                            if (address[i] != '\0') {
+                                putc(address[i]);
                             }
                         }
                         putc('\n');    
                     }
                     
+                    // Debug printing
+                    // print("Freeing allocated memory...\n");
+                    freeBlocks(address, neededBlocks);
+                    // print("Done!\n");
+
                     break;
                 }
 

src/kernel.ld

@@ -1,5 +1,6 @@
 SECTIONS {
     .text 0x1000 : {
+        *(entry);
         *(.text*);
     }
     .data : {