From 94c2a1626d7d60277c2a9a9db9e06c73362fc957 Mon Sep 17 00:00:00 2001
From: Elaina Claus <elaina.claus@chtm.me>
Date: Fri, 18 Oct 2024 07:57:42 -0400
Subject: [PATCH] correct some field sizes

---
 include/BIOS/func/ext_read.nasm |  7 +++++--
 include/util/kmem_func.nasm     | 10 +++++-----
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/include/BIOS/func/ext_read.nasm b/include/BIOS/func/ext_read.nasm
index 72ddc4a..e27322b 100644
--- a/include/BIOS/func/ext_read.nasm
+++ b/include/BIOS/func/ext_read.nasm
@@ -98,13 +98,16 @@ read_disk_raw:
     mov ax, [bp + 12]
     mov word [bx + LBAPkt_t.xfer_size], ax
 
-    mov eax, [bp + 8]
+    mov eax, dword [bp + 8]
     mov dword [bx + LBAPkt_t.lower_lba], eax
 
+    ; upper_lba is zero from kmemset
+    ; TODO: possiblly support >32bit LBA addresses in the future, this limits us to 4GiB
+
     mov ax, [bp + 6]
     mov word [bx + LBAPkt_t.offset], ax
 
-    movzx ax, byte [bp + 4]
+    mov ax, [bp + 4]
     mov word [bx + LBAPkt_t.segment], ax
 
     xor ax, ax
diff --git a/include/util/kmem_func.nasm b/include/util/kmem_func.nasm
index 2c5ad3d..305c133 100644
--- a/include/util/kmem_func.nasm
+++ b/include/util/kmem_func.nasm
@@ -21,18 +21,18 @@
 %ifndef __INC_KMEM_FUNC
 %include 'cdecl16.inc'
 
-; uint8_t* kmemset_byte(void* dst, uint8_t val, uint16_t len);
+; void* kmemset_byte(void* dst, uint8_t val, uint16_t len);
 ALIGN 4, db 0x90
 kmemset:
     __CDECL16_ENTRY
  .func:
-    mov     cx, [bp + 8]   ; size_t len
-    mov     al, [bp + 6]   ; uint8_t val
-    mov     di, [bp + 4]   ; void * dst
+    mov     cx, [bp + 8]        ; uint16_t len
+    mov     al, byte [bp + 6]   ; uint8_t val
+    mov     di, [bp + 4]        ; void * dst
 
     cld
     rep     stosb
-    mov     ax, di         ; return pointer to dest
+    mov     ax, di         ; return pointer to dest + len (last elem of dest)
 .endp:
     __CDECL16_EXIT
     ret