[Experimental] [Driver-related] Add device abstraction for cleaner code

Makefile

@@ -13,7 +13,7 @@ BIN = sysroot/boot/hhhos.bin
 ISO = build/HhhOS.iso
 
 OBJS = build/boot.o build/kernel.o build/string.o build/terminal.o build/idt.o \
-build/isr.o build/util.o build/keyboard.o build/pic.o
+build/isr.o build/util.o build/device.o build/keyboard.o build/pic.o
 
 ARCHDIR = arch/$(ARCH)/
 

arch/i386/device.c

@@ -0,0 +1,30 @@
+#include <device.h>
+
+int _device_index = 0;
+
+struct device descriptors[64];
+
+int push_device(struct device device) {
+    int descriptor = _device_index;
+
+    descriptors[descriptor] = device;
+    _device_index++;
+
+    return descriptor;
+}
+
+void* read(int descriptor, void* data) {
+    if (descriptor >= _device_index) return -1;
+
+    struct device device = descriptors[descriptor];
+
+    return device.read(data);
+}
+
+void* write(int descriptor, void* data) {
+    if (descriptor >= _device_index) return -1;
+
+    struct device device = descriptors[descriptor];
+
+    return device.write(data);
+}

arch/i386/kernel.c

@@ -3,6 +3,7 @@
 #include <isr.h>
 #include <keyboard.h>
 #include <pic.h>
+#include <device.h>
 
 /* Check if the compiler thinks you are targeting the wrong operating system. */
 #if defined(__linux__)
@@ -24,7 +25,9 @@ void kmain() {
     isr_install();
     terminal_writeline("done");
     terminal_writestring("Preparing keyboard... ");
-    keyboard_init();
+    int keyboard_descriptor = keyboard_init();
+    terminal_writestring("done, descriptor: ");
+    terminal_writeline(itoa(keyboard_descriptor));
     
     terminal_writestring("Are interrupts enabled? ");
     if (are_interrupts_enabled() == 1) {
@@ -39,6 +42,9 @@ void kmain() {
         terminal_writeline("no");
     }
 
+    terminal_writestring("kmain memory address: ");
+    terminal_writeline(itoa(kmain));
+
     terminal_writeline("----------");
 
     terminal_writeline("hello yes");

arch/i386/keyboard.c

@@ -1,6 +1,7 @@
 #include <pic.h>
 #include <keyboard.h>
 #include <stdbool.h>
+#include <device.h>
 
 unsigned char kbdus[128] = {
         0, 27, '1', '2', '3', '4', '5', '6', '7', '8',    /* 9 */
@@ -44,6 +45,10 @@ unsigned char kbdus[128] = {
 uint8_t lastkey = 0;
 uint8_t __kbd_enabled = 0;
 
+unsigned char keyboard_get_key_from_scancode(unsigned char scancode) {
+    return kbdus[scancode];
+}
+
 __attribute__((interrupt)) static void keyboard_irq(struct interrupt_frame* frame) {
     unsigned char scancode = inportb(0x60);
 
@@ -72,26 +77,39 @@ __attribute__((interrupt)) static void keyboard_irq(struct interrupt_frame* fram
         return;
     }
 
-    if (!special) terminal_putchar(kbdus[scancode]);
+    if (!special) terminal_putchar(keyboard_get_key_from_scancode(scancode));
     terminal_updatecursor();
 	pic_send_eoi(1);
 }
 
-void keyboard_init(void) {
-    pic_irq_enable(1);
-    idt_register_handler(33, (uint32_t)keyboard_irq);
-
-    __kbd_enabled = 1;
-
-    terminal_writeline("haha keyboard go brr");
-}
-
 uint8_t keyboard_enabled(void) {
     return __kbd_enabled;
 }
 
-void keyboard_read_key(void) {
-    lastkey = 0;
-    if (inportb(0x64) & 1)
-        lastkey = inportb(0x60);
+void* keyboard_read(void* data) {
+    if (inportb(0x64) & 1) {
+        return keyboard_get_key_from_scancode(inportb(0x60));
+    } else {
+        return -1;
+    }
 }
+
+void* keyboard_write(void* data) {
+    return -1;
+}
+
+int keyboard_init(void) {
+    pic_irq_enable(1);
+    idt_register_handler(33, (uint32_t)keyboard_irq);
+
+    __kbd_enabled = 1;
+
+    struct device keyboard_device = {
+        write: &keyboard_write,
+        read: &keyboard_read
+    };
+
+    int keyboard_descriptor = push_device(keyboard_device);
+
+    return keyboard_descriptor;
+}

include/device.h

@@ -0,0 +1,22 @@
+#ifndef _DEVICE_H
+#define _DEVICE_H 1
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct device {
+    void* (*write)(void* data);
+    void* (*read)(void* data);
+};
+
+int push_device(struct device device);
+
+void* read(int descriptor, void* data);
+void* write(int descriptor, void* data);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _DEVICE_H */

include/keyboard.h

@@ -10,7 +10,7 @@
 extern "C" {
 #endif
 
-void keyboard_init(void);
+int keyboard_init(void);
 uint8_t keyboard_enabled(void);
 
 #ifdef __cplusplus