big chungus

* fix a heap corruption bug
* add qemu support
* add an ATA driver
* add an USTAR read-only file system
* boot from disk instead of floppy
* font rendering
* image rendering
* PCI enumeration
* init script

1 files changed, 56 insertions, 0 deletions

diff --git a/stage3/string.c b/stage3/string.c
new file mode 100644
index 0000000..ff4bfc3
--- /dev/null
+++ b/stage3/string.c
@@ -0,0 +1,56 @@
+#include "string.h"
+
+usize find_char(const char *str, char chr)
+{
+	usize ret = 0;
+	while (*str != chr && *str != '\0')
+		str++, ret++;
+	return ret;
+}
+
+u64 parse_num(u8 **str, u8 base, isize size)
+{
+	u64 x = 0;
+
+	while (size-- != 0) {
+		u8 c = **str;
+
+		u64 d;
+		if (c >= '0' && c <= '9')
+			d = c - '0';
+		else if (c >= 'a' && c <= 'z')
+			d = c - 'a';
+		else if (c >= 'A' && c <= 'z')
+			d = c - 'A';
+		else
+			return x;
+
+		if (d >= base)
+			return x;
+
+		(*str)++;
+		x = x * base + d;
+	}
+
+    return x;
+}
+
+usize strlen(const char *str)
+{
+	return find_char(str, '\0');
+}
+
+int strcmp(const char *p1, const char *p2)
+{
+	while (*p1 == *p2 && *p1 != '\0')
+		p1++, p2++;
+	return *p1 - *p2;
+}
+
+int strncmp(const char *p1, const char *p2, usize size)
+{
+	for (usize i = 0; i < size; i++)
+		if (p1[i] != p2[i])
+			return p1[i]-p2[i];
+	return 0;
+}