From b717387adb0c9197c70cd361e1d08a83e426f478 Mon Sep 17 00:00:00 2001
From: kamkow1 <kamkow256@gmail.com>
Date: Sat, 11 Oct 2025 21:36:33 +0200
Subject: [PATCH] Implement random number generation with x86 rdrand

---
 kernel/hal/hal.h            |  1 +
 kernel/hal/x86_64/randnum.S | 13 +++++++++++++
 2 files changed, 14 insertions(+)
 create mode 100644 kernel/hal/x86_64/randnum.S

diff --git a/kernel/hal/hal.h b/kernel/hal/hal.h
index a4de5af..dd74a89 100644
--- a/kernel/hal/hal.h
+++ b/kernel/hal/hal.h
@@ -19,6 +19,7 @@ size_t hal_strspn(const char *s, const char *accept);
 char *hal_strcpy(char *dest, const char *src);
 char *hal_strchr(const char *s, int c);
 void hal_wait(uint32_t ms);
+int32_t hal_randnum(void);
 
 #define HAL_PAGE_SIZE 0x1000
 #include "x86_64/vmm.h"
diff --git a/kernel/hal/x86_64/randnum.S b/kernel/hal/x86_64/randnum.S
new file mode 100644
index 0000000..6f74c1d
--- /dev/null
+++ b/kernel/hal/x86_64/randnum.S
@@ -0,0 +1,13 @@
+.global hal_randnum
+hal_randnum:
+  mov $100, %ecx
+  xor %eax, %eax
+
+.retry:
+  rdrand %eax
+  jc .done
+  loop .retry
+.fail:
+  mov $-1, %eax
+.done:  
+  ret