From 89ebe30ad8a60820b810ecac23fc264ea6c95c19 Mon Sep 17 00:00:00 2001
From: Elaina Claus <elaina.claus@chtm.me>
Date: Thu, 3 Oct 2024 19:52:24 -0400
Subject: [PATCH] forking kmemset functions for stage2 usage

---
 include/kmem_func.inc | 53 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 include/kmem_func.inc

diff --git a/include/kmem_func.inc b/include/kmem_func.inc
new file mode 100644
index 0000000..e7e7080
--- /dev/null
+++ b/include/kmem_func.inc
@@ -0,0 +1,53 @@
+; Copyright (c) 2024 Elaina Claus
+;
+; Permission is hereby granted, free of charge, to any person obtaining a copy
+; of this software and associated documentation files (the "Software"), to deal
+; in the Software without restriction, including without limitation the rights
+; to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+; copies of the Software, and to permit persons to whom the Software is
+; furnished to do so, subject to the following conditions:
+;
+; The above copyright notice and this permission notice shall be included in all
+; copies or substantial portions of the Software.
+;
+; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+; SOFTWARE.
+
+; uint8_t* kmemset(void* dest, uint8_t val, size_t len);
+kmemset:
+    push    di             ; function uses di, so save it.
+ 
+    mov     cx, [bp - 2]   ; size_t len
+    mov     al, [bp - 4]   ; uint8_t val
+    mov     di, [bp - 6]   ; void * ptr
+
+    cld
+    rep     stosb 
+.endf:
+    mov     ax, [bp - 6]  ; return pointer to dest
+    pop     di            ; restore di
+    ret
+
+; uint8_t* kmemset(uint8_t* dest, uint8_t* src, size_t len);
+; not overlap safe
+kmemcpy:
+    push di
+    push si                 ; di, si are callee save
+
+    mov cx, [bp - 2]        ; length
+    mov si, [bp - 4]        ; source
+    mov di, [bp - 6]        ; dest
+    
+    cld                     ; ensure we are incrementing
+    rep movsb
+
+.endf:
+    mov ax, [bp - 6]        ; return pointer to dest
+    pop si
+    pop di
+    ret
\ No newline at end of file