FINALLY Added Disk support!!! f_disk.c name explanation in README.md

Disk reading only, but it works!

src/kernel/disk.c

@@ -1 +0,0 @@
-#include "disk.h"

src/kernel/disk.h

@@ -1,8 +1,11 @@
-#ifndef DISK_H
-#define DISK_H
+#ifndef DRIVE_H
+#define DRIVE_H
 
 #include "stdint.h"
 
 extern uint8_t driveNum;
 
+void diskRead(uint8_t sector, uint8_t sectorCount, uint8_t drive, char* dst);
+void diskWrite(uint8_t sector, uint8_t sectorCount, uint8_t drive, const char* src);
+
 #endif

src/kernel/entry.asm

@@ -1,5 +1,6 @@
 [bits 32]
 [global _start]
+[global driveNum]
 
 [extern main]
 [extern idtp]
@@ -19,7 +20,6 @@ _start:
 
     jmp $       ;; If we used cli, hlt we wouldn't have interrupts :/
 
-[global driveNum]
 driveNum: db 0
 
 ;;

src/kernel/f_disk.c

@@ -0,0 +1,27 @@
+#include "disk.h"
+#include "stdint.h"
+#include "system.h"
+
+#define PIO_PORT 0x1f0
+
+void diskRead(uint8_t sector, uint8_t sectorCount, uint8_t drive, char* dst) {
+    outb(PIO_PORT + 6, (drive & 0x0f) | 0xa0); // Head and drive number port
+    outb(PIO_PORT + 2, sectorCount); // Sector count
+    outb(PIO_PORT + 3, sector); // Sector to start reading at
+    outb(PIO_PORT + 4, 0); // Cylinder number low
+    outb(PIO_PORT + 5, 0); // Cylinder number high
+    outb(PIO_PORT + 7, 0x20); // Command register, 0x20 - Read with retry
+    
+    while (inb(PIO_PORT + 7) == 8); // Status register, wait until ready
+
+    uint32_t i = 512 * sectorCount;
+    while (i > 0) {
+        uint16_t data = inw(PIO_PORT); // Data port
+        *dst++ = (uint8_t)(data);
+        *dst++ = (uint8_t)(data >> 8);
+        i--;
+    }
+}
+
+void diskWrite(uint8_t sector, uint8_t sectorCount, uint8_t drive, const char* src);
+

src/kernel/main.c

@@ -52,10 +52,20 @@ void main() {
             print("Available Commands:\n", 0x0f);
             print(" clear      | Clears the screen\n", 0x0f);
             print(" echo       | Prints a message to stdout\n", 0x0f);
-            print(" exit       | Exits program\n", 0x0f);
+            print(" exit       | Exits shell\n", 0x0f);
             print(" help       | Prints this message\n", 0x0f);
             // TODO: print(" ls         | Lists all available files\n", 0x0f);
             // TODO: print(" reboot     | Reboots the system\n", 0x0f);
+            print(" test       | Tests the latest feature [DEBUG]\n", 0x0f);
+        } else if (strcmp(input, "test") == 0) {
+            char buf[512];
+            print("Reading from drive 0x", 0x0f);
+            print(itoa(driveNum, 16), 0x0f);
+            print("...\n", 0x0f);
+            diskRead(22, 1, driveNum, buf);
+
+            print(buf, 0x0f);
+            putc('\n', 0x0f);
         } else {
             print("Command not found: ", 0x0c);
             print(input, 0x0c);

src/kernel/system.c

@@ -3,12 +3,22 @@
 
 uint8_t inb(uint16_t port) {
     uint8_t result;
-    asm volatile("in %1, %0" : "=a"(result) : "Nd"(port));
+    asm volatile("inb %1, %0" : "=a"(result) : "Nd"(port));
     return result;
 }
 
 void outb(uint16_t port, uint8_t data) {
-    asm volatile("out %0, %1" :: "a"(data), "Nd"(port));
+    asm volatile("outb %0, %1" :: "a"(data), "Nd"(port));
+}
+
+uint16_t inw(uint16_t port) {
+    uint16_t result;
+    asm volatile("inw %1, %0" : "=a"(result) : "Nd"(port));
+    return result;
+}
+
+void outw(uint16_t port, uint16_t data) {
+    asm volatile("outw %0, %1" :: "a"(data), "Nd"(port));
 }
 
 char* memcopy(char* src, char* dst, uint16_t length) {

src/kernel/system.h

@@ -7,6 +7,9 @@
 uint8_t inb(uint16_t port);
 void outb(uint16_t port, uint8_t data);
 
+uint16_t inw(uint16_t port);
+void outw(uint16_t port, uint16_t data);
+
 // Memory functions
 char* memcopy(char* src, char* dst, uint16_t length);
 char* memset(char* dst, char data, uint16_t length);