From b7b97d32cbb6fbc928078ebe3a00714cbbebea86 Mon Sep 17 00:00:00 2001
From: EmulatedSeasons <89668582+EmulatedSeasons@users.noreply.github.com>
Date: Fri, 29 Dec 2023 01:38:34 -0500
Subject: got grub memory map and added to kernel printf

---
 kernel/std/printf.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 118 insertions(+), 6 deletions(-)

(limited to 'kernel/std/printf.c')

diff --git a/kernel/std/printf.c b/kernel/std/printf.c
index c383cad..fe45892 100644
--- a/kernel/std/printf.c
+++ b/kernel/std/printf.c
@@ -3,7 +3,8 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
- 
+#include <stdint.h>
+
 static bool print(const char* data, size_t length) {
 	const unsigned char* bytes = (const unsigned char*) data;
 	for (size_t i = 0; i < length; i++)
@@ -11,13 +12,82 @@ static bool print(const char* data, size_t length) {
 			return false;
 	return true;
 }
- 
+
+// for %d and %x.
+static const char* itoa(unsigned int num, char* str, unsigned int base) {
+	asm("xchgw %bx, %bx");
+	int cou = 0; // nt
+
+    if (num == 0) { // 0
+		str[cou] = '0';
+		str[++cou] = '\0';
+		return str;
+	}
+
+	while (num)
+	{
+		unsigned int rem = (num % base);
+		// brings the number up to ascii 0 + the digit
+		if (rem > 9) {
+			str[cou] = rem + '7'; // 7 = 55 + 10(A) = 65
+		} else {
+			str[cou] = rem + '0';
+		}
+		num /= base;
+		++cou;
+	}
+	
+	// reverse the string
+	for (int i = 0; i < cou; i++) {
+		char temp = str[i];
+		str[i] = str[cou - i - 1]; 
+		str[cou - 1] = temp;
+	}
+
+	str[cou] = '\0';
+	return str;
+}
+
+// have no idea if there's a better way to do this. for %lx
+static const char* itoa_u64(unsigned long long num, char* str, int base) {
+	int cou = 0; // nt
+
+    if (num == 0) { // 0
+		str[cou] = '0';
+		str[++cou] = '\0';
+		return str;
+	}
+
+	while (num)
+	{
+		unsigned long long rem = num % base;
+		// brings the number up to ascii 0 + the digit
+		if (rem > 9) {
+			str[cou] = rem + '7'; // 7 = 55 + 10(A) = 65
+		} else {
+			str[cou] = rem + '0';
+		}
+		num /= base;
+		++cou;
+	}
+	
+	// reverse the string
+	for (int i = 0; i < cou; i++) {
+		char temp = str[i];
+		str[i] = str[cou - i - 1]; 
+		str[cou - 1] = temp;
+	}
+
+	str[cou] = '\0';
+	return str;
+}
+
 int printf(const char* restrict format, ...) {
 	va_list parameters;
 	va_start(parameters, format);
  
 	int written = 0;
- 
+
 	while (*format != '\0') {
 		size_t maxrem = INT_MAX - written;
  
@@ -37,9 +107,9 @@ int printf(const char* restrict format, ...) {
 			written += amount;
 			continue;
 		}
- 
+
 		const char* format_begun_at = format++;
- 
+
 		if (*format == 'c') {
 			format++;
 			char c = (char) va_arg(parameters, int /* char promotes to int */);
@@ -50,6 +120,48 @@ int printf(const char* restrict format, ...) {
 			if (!print(&c, sizeof(c)))
 				return -1;
 			written++;
+		} else if (*format == 'd') {
+			format++;
+			char str[20]; // probably a long enough buffer
+			unsigned int d = va_arg(parameters, unsigned int);
+			itoa(d, str, 10);
+			size_t len = strlen(str);
+			if (maxrem < len) {
+				// TODO: Set errno to EOVERFLOW.
+				return -1;
+			}
+			if (!print(str, len))
+				return -1;
+			written += len;
+		} else if (*format == 'x') {
+			format++;
+			char str[20]; // probably a long enough buffer
+			unsigned int d = va_arg(parameters, unsigned int);
+			itoa(d, str, 16);
+			size_t len = strlen(str);
+			if (maxrem < len) {
+				// TODO: Set errno to EOVERFLOW.
+				return -1;
+			}
+			if (!print(str, len))
+				return -1;
+			written += len;
+		} else if (*format == 'l') { // for %lx and others that start with l
+			format++;
+			if (*format == 'x') {
+				format++;
+				char str[20]; // probably a long enough buffer
+				unsigned long long d = va_arg(parameters, unsigned long long);
+				itoa_u64(d, str, 16);
+				size_t len = strlen(str);
+				if (maxrem < len) {
+					// TODO: Set errno to EOVERFLOW.
+					return -1;
+				}
+				if (!print(str, len))
+					return -1;
+				written += len;
+			}
 		} else if (*format == 's') {
 			format++;
 			const char* str = va_arg(parameters, const char*);
@@ -74,7 +186,7 @@ int printf(const char* restrict format, ...) {
 			format += len;
 		}
 	}
- 
+
 	va_end(parameters);
 	return written;
 }
\ No newline at end of file
-- 
cgit v1.2.3-70-g09d2