From 6a6f31db520177d15a604ebd77ec68b7fc94dce6 Mon Sep 17 00:00:00 2001
From: Jake Mannens <jake72360@gmail.com>
Date: Sun, 17 Jun 2018 04:10:41 +1000
Subject: Added basic implmementation of %x to vsprintf.

---
 kernel/vsprintf.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'kernel/vsprintf.c')

diff --git a/kernel/vsprintf.c b/kernel/vsprintf.c
index dca2906..20489f4 100644
--- a/kernel/vsprintf.c
+++ b/kernel/vsprintf.c
@@ -8,7 +8,22 @@ enum TYPE {
   TYPE_STRING = 4
 };
 
+static void hex(char **str, int x) {
+  int n;
+  char *s = "0x";
+
+  while(*s)
+    *(*str)++ = *s++;
+
+  n = sizeof(x) << 1;
+  while(n--) {
+    *(*str)++ = ((unsigned int) x >> 28) + 0x30;
+    x = x << 4;
+  }
+}
+
 int vsprintf(char *str, char *fmt, va_list ap) {
+  int x;
   char *s;
   char *start = str;
   uint8_t type;
@@ -29,6 +44,11 @@ int vsprintf(char *str, char *fmt, va_list ap) {
             goto done;
           type = TYPE_STRING;
           break;
+        case 'x':
+          if(type)
+            goto done;
+          type = TYPE_HEX;
+          break;
         default:
           goto done;
           break;
@@ -44,6 +64,10 @@ done:
         while(*s)
           *str++ = *s++;
         break;
+      case TYPE_HEX:
+        x = va_arg(ap, int);
+        hex(&str, x);
+        break;
     }
   }
 
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