From 5ec9cc709f8593d63fe666252840dc91082bceb3 Mon Sep 17 00:00:00 2001
From: Lauchmelder <robert.trololo@gmail.com>
Date: Thu, 20 Jan 2022 16:38:03 +0100
Subject: [PATCH] added more int to string conversions

---
 include/convert.h |  6 +++++-
 src/boot.S        |  4 +++-
 src/convert.c     | 40 ++++++++++++++++++++++++++++++++--------
 src/kernel.c      | 30 +++++++++++++++---------------
 4 files changed, 55 insertions(+), 25 deletions(-)

diff --git a/include/convert.h b/include/convert.h
index 118a576..d4bb0f9 100644
--- a/include/convert.h
+++ b/include/convert.h
@@ -3,4 +3,8 @@
 #include "stdint.h"
 
 int stoi(const char* string);
-char* itoa(int number, char* string);
\ No newline at end of file
+
+char* ultoa(unsigned long number, char* string, int base);
+char* ltoa(long number, char* string, int base);
+char* utoa(unsigned int number, char* string, int base);
+char* itoa(int number, char* string, int base);
\ No newline at end of file
diff --git a/src/boot.S b/src/boot.S
index ec7b34a..c08a0e4 100644
--- a/src/boot.S
+++ b/src/boot.S
@@ -24,6 +24,8 @@ _start:
     cbnz    w2, 3b
 
 4:  # Jump to main() in C
-    ldr     x4, =_start
+    ldr     x0, =_start
+    ldr     x1, =0x50000
+    str     x0, [x1]
     bl      main
     b       1b
\ No newline at end of file
diff --git a/src/convert.c b/src/convert.c
index 688a70a..8387603 100644
--- a/src/convert.c
+++ b/src/convert.c
@@ -21,8 +21,14 @@ int stoi(const char* string)
     return output;
 }
 
-char* itoa(int number, char* string)
+char* ultoa(unsigned long number, char* string, int base)
 {
+    if(base < 2 || base > 16)
+    {
+        string[0] = '\0';
+        return string;
+    }
+
     volatile char* temp = (volatile char*)0x40000000;
     int i = 0;
     if(number == 0)
@@ -31,17 +37,12 @@ char* itoa(int number, char* string)
     }
     else
     {
-        for(int n = (number < 0 ? -number : number); n > 0; n /= 10)
+        for(; number > 0; number /= base)
         {
-            temp[i++] = '0' + (n % 10);
+            temp[i++] = '0' + (number % base);
         }
     }
 
-    if(number < 0)
-    {
-        temp[i++] = '-';
-    }
-
     temp[i] = '\0';
     string[i] = '\0';
 
@@ -51,4 +52,27 @@ char* itoa(int number, char* string)
     }
 
     return string;
+}
+
+char* ltoa(long number, char* string, int base)
+{
+    char* old_string = string;
+    if(number < 0)
+    {
+        number *= -1;
+        *string++ = '-';
+    }
+    
+    itoa(number, string, base);
+    return old_string;
+}
+
+char* utoa(unsigned int number, char* string, int base)
+{
+    return ultoa(number, string, base);
+}
+
+char* itoa(int number, char* string, int base)
+{
+     return ltoa(number, string, base);
 }
\ No newline at end of file
diff --git a/src/kernel.c b/src/kernel.c
index bc9fd97..bb43f1b 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -3,29 +3,24 @@
 #include "string.h"
 
 void print_clippy();
+char* get_user_input(char* buffer);
 
 void main()
 {
     const char* hex_chars = "0123456789ABCDEF";
-    register int* start_address asm ("x4");
-    long int start = (long int)start_address;
+    long int start = *(volatile long int*)0x50000;
+    char buffer[1024];
 
     uart_init();
     print_clippy();
     uart_puts("Boot successful! \n");
     uart_puts("Started execution at 0x");
-    for(int i = 0; i < 8; i++)
-    {
-        uart_putchar(hex_chars[start & 0xF]);
-        start >>= 4;
-    }
+    uart_puts(ultoa(start, buffer, 16));
 
-    char buffer[1024];
     for(;;)
     {
         uart_puts("\n\nPlease enter first operand\n");
-        uart_puts("📎 "); 
-        uart_gets(buffer);
+        get_user_input(buffer);
         
         if(!strcmp(buffer, "clippy"))
         {
@@ -36,18 +31,23 @@ void main()
         int a = stoi(buffer);
 
         uart_puts("\nPlease enter second operand\n");
-        uart_puts("📎 "); 
-        int b = stoi(uart_gets(buffer));
+        int b = stoi(get_user_input(buffer));
 
         uart_puts("\n");
-        uart_puts(itoa(a, buffer));
+        uart_puts(itoa(a, buffer, 10));
         uart_puts(" * ");
-        uart_puts(itoa(b, buffer));
+        uart_puts(itoa(b, buffer, 10));
         uart_puts(" = ");
-        uart_puts(itoa(a * b, buffer));
+        uart_puts(itoa(a * b, buffer, 10));
     }
 }
 
+char* get_user_input(char* buffer)
+{
+    uart_puts("📎 "); 
+    return uart_gets(buffer);
+}
+
 void print_clippy()
 {
     uart_puts("    ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀   \n");