From 6a020aeeee7ce01875f0632a6f31a316b320e3a5 Mon Sep 17 00:00:00 2001
From: Nocturn9x <hackhab@gmail.com>
Date: Fri, 18 Nov 2022 02:40:46 +0100
Subject: [PATCH] Added kprintln and memset

---
 include/kernel/drivers/vga/screen.h |  1 +
 include/kernel/types.h              |  8 +++++++-
 include/kernel/util.h               |  3 ++-
 src/boot/mbr.s                      |  2 +-
 src/kernel/drivers/vga/screen.c     |  9 +++++++++
 src/kernel/main.c                   |  6 +++---
 src/kernel/util.c                   | 13 +++++++++++++
 7 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/include/kernel/drivers/vga/screen.h b/include/kernel/drivers/vga/screen.h
index 8f7b4f8..5200000 100644
--- a/include/kernel/drivers/vga/screen.h
+++ b/include/kernel/drivers/vga/screen.h
@@ -41,6 +41,7 @@ limitations under the License.
 void clearScreen(void);
 void kprintAt(char* message, i32 col, i32 row);
 void kprint(char* message);
+void kprintln(char* message);
 
 
 #endif
\ No newline at end of file
diff --git a/include/kernel/types.h b/include/kernel/types.h
index 2fbf3a5..890fd58 100644
--- a/include/kernel/types.h
+++ b/include/kernel/types.h
@@ -22,7 +22,13 @@ limitations under the License.
 #define true 1
 #define false 0
 
-typedef unsigned char byte;
+// Some of these are duplicates, but their meaning
+// is purely contextual (to make it clearer what is
+// what in a given function)
+
+typedef char i8;
+typedef char byte;
+typedef unsigned char u8;
 typedef unsigned short int u16;
 typedef short int i16;
 typedef unsigned int u32;
diff --git a/include/kernel/util.h b/include/kernel/util.h
index 4823221..0654017 100644
--- a/include/kernel/util.h
+++ b/include/kernel/util.h
@@ -20,6 +20,7 @@ limitations under the License.
 #include "kernel/types.h"
 
 void copystr(const char* source, char* dest, i32 n);
-void itoa(i32 i, char* a);
+void memset(u8* dest, u8 val, u32 len);
+void itoa(const i32 i, char* a);
 
 #endif
\ No newline at end of file
diff --git a/src/boot/mbr.s b/src/boot/mbr.s
index 6a129c4..8fde586 100644
--- a/src/boot/mbr.s
+++ b/src/boot/mbr.s
@@ -58,7 +58,7 @@ load_kernel:    ; Loads the kernel into memory
     mov si, loading_kernel_msg
     call bios_println
     mov bx, kernel_offset
-    mov dh, 3
+    mov dh, 4
     mov dl, [boot_drive]
     call load_disk
     ret
diff --git a/src/kernel/drivers/vga/screen.c b/src/kernel/drivers/vga/screen.c
index e12d360..b4295a4 100644
--- a/src/kernel/drivers/vga/screen.c
+++ b/src/kernel/drivers/vga/screen.c
@@ -68,6 +68,15 @@ void kprint(char* message) {
 }
 
 
+void inline kprintln(char* message) {
+    /*
+    Identical to kprint, but calls
+    kprint("\n") afterwards
+    */
+   kprint(message);
+   kprint("\n");
+}
+
 // Private API below
 
 i32 putchar(byte ch, i32 col, i32 row, byte attr) {
diff --git a/src/kernel/main.c b/src/kernel/main.c
index f1af790..7cfbfeb 100644
--- a/src/kernel/main.c
+++ b/src/kernel/main.c
@@ -24,9 +24,9 @@ i32 kmain(void) {
     The kernel entry point of TSOS
     */
 
-    // Newline so we skip the log
-    // messages from the bootloader
-    kprint("\nTSOS: Kernel load OK");
+    // We skip the log messages from 
+    // the bootloader
+    kprintln("\n\n\n\nTSOS: Kernel load OK");
     // TODO...
     return 0x022172; // :D
 }
\ No newline at end of file
diff --git a/src/kernel/util.c b/src/kernel/util.c
index e237d29..8b0cb3a 100644
--- a/src/kernel/util.c
+++ b/src/kernel/util.c
@@ -17,6 +17,7 @@ limitations under the License.
 #include "kernel/types.h"
 #include "kernel/util.h"
 
+
 void copystr(const char* restrict source, char* restrict dest, i32 n) {
     /*
     Copies n bytes from source to dest. The two memory locations may
@@ -34,6 +35,18 @@ void copystr(const char* restrict source, char* restrict dest, i32 n) {
 }
 
 
+void memset(u8* dest, u8 val, u32 len) {
+    /*
+    Implementation for memset
+    */
+    u8* temp = (u8*)dest;
+    while (len) {
+        *temp++ = val;
+        len--;
+    }
+}
+
+
 i32 countDigits(i32 n) {
     /*
     Returns the number of digits