[drivers][keyboard] Precompute scancode to ASCII mapping

Author: scopeInfinity

Makefile

@@ -87,7 +87,7 @@ debug_kernel: $(kernel_core)
 	xxd $<
 
 qemu: $(image_vmdk)
-	cpulimit -f -l 10 -- qemu-system-x86_64 -smp 1 -m 128M -hda $< -no-shutdown -no-reboot
+	cpulimit -f -l 100 -- qemu-system-x86_64 -smp 1 -m 128M -hda $< -no-shutdown -no-reboot
 
 qemu_debug: $(image_vmdk)
 	qemu-system-x86_64 -smp 1 -m 128M -hda $< -no-shutdown -no-reboot -d  cpu,exec,in_asm

src/drivers/keyboard/keyboard.c

@@ -138,10 +138,12 @@ unsigned char read_data_reply() {
 #define KEYBOARD_BUFFER_SIZE 64
 int keyboard_buffer[KEYBOARD_BUFFER_SIZE+3];
 
+void keyboard_scanner_handler_init();
 int keyboard_scanner_handle_buffer(int keyboard_buffer_queue[]);
 
 void keyboard_scanner_init() {
     ASSERT( queue_init(keyboard_buffer, KEYBOARD_BUFFER_SIZE) );
+    keyboard_scanner_handler_init();
 }
 
 int keyboard_scanner_step() {

src/drivers/keyboard/scancode_handler.c

@@ -171,7 +171,7 @@ static const unsigned char KEYBOARD_ASCII_MAPH_OTHERS[] = {
     KEYBOARD_SC_RPF0_blackslash, '\\'
 };
 
-
+static unsigned char KEYBOARD_ASCII_MAPPING[256];
 static char last_ascii;
 static int last_ascii_available = 0;
 static char tmp_juggad_is_f0 = 0;
@@ -185,6 +185,28 @@ char keyboard_scanner_ascii_get() {
     return last_ascii;
 }
 
+void keyboard_scanner_handler_init() {
+    for (int i = 0; i < sizeof(KEYBOARD_ASCII_MAPPING); ++i) {
+        KEYBOARD_ASCII_MAPPING[i] = 0;
+    }
+    for(int i = 0;i<sizeof(KEYBOARD_ASCII_MAPH_AZ);i++) {
+        unsigned char code = KEYBOARD_ASCII_MAPH_AZ[i];
+        unsigned char c = 'a'+i;
+        KEYBOARD_ASCII_MAPPING[code]=c;
+    }
+     for(int i = 0;i<sizeof(KEYBOARD_ASCII_MAPH_09);i++) {
+        unsigned char code = KEYBOARD_ASCII_MAPH_09[i];
+        unsigned char c = '0'+i;
+        KEYBOARD_ASCII_MAPPING[code]=c;
+    }
+    if(last_ascii_available) return 1;
+    for(int i = 0;i<sizeof(KEYBOARD_ASCII_MAPH_OTHERS);i+=2) {
+        unsigned char code = KEYBOARD_ASCII_MAPH_OTHERS[i];
+        unsigned char c = KEYBOARD_ASCII_MAPH_OTHERS[i+1];
+        KEYBOARD_ASCII_MAPPING[code]=c;
+    }
+}
+
 int keyboard_scanner_handle_buffer(int keyboard_buffer[]) {
     // For now just taking care of some of the key press and disgarding others.
     int len = queue_size(keyboard_buffer);
@@ -203,28 +225,9 @@ int keyboard_scanner_handle_buffer(int keyboard_buffer[]) {
         return 1;
     }
 
-    for(int i = 0;i<sizeof(KEYBOARD_ASCII_MAPH_AZ);i++) {
-        if(KEYBOARD_ASCII_MAPH_AZ[i]==c0) {
-            last_ascii = 'a'+i;
-            last_ascii_available = 1;
-            break;
-        }
-    }
-    if(last_ascii_available) return 1;
-    for(int i = 0;i<sizeof(KEYBOARD_ASCII_MAPH_09);i++) {
-        if(KEYBOARD_ASCII_MAPH_09[i]==c0) {
-            last_ascii = '0'+i;
-            last_ascii_available = 1;
-            break;
-        }
-    }
-    if(last_ascii_available) return 1;
-    for(int i = 0;i<sizeof(KEYBOARD_ASCII_MAPH_OTHERS);i+=2) {
-        if(KEYBOARD_ASCII_MAPH_OTHERS[i]==c0) {
-            last_ascii = KEYBOARD_ASCII_MAPH_OTHERS[i+1];
-            last_ascii_available = 1;
-            break;
-        }
+    if(KEYBOARD_ASCII_MAPPING[c0]>0) {
+        last_ascii = KEYBOARD_ASCII_MAPPING[c0];
+        last_ascii_available = 1;
     }
     if(last_ascii_available) return 1;
     return 0;

src/kernel/core.c

@@ -3,6 +3,7 @@
 #include <lib/utils/output.h>
 #include <lib/utils/input.h>
 #include <lib/utils/panic.h>
+#include <lib/utils/time.h>
 
 #include "kernel/essentials.c"
 #include "kernel/interrupts.c"