clear the carry flag before calling BIOS functions

2025-09-05 10:33:42 -04:00
parent c3871d2b7d
commit a53534acd2
4 changed files with 6 additions and 0 deletions
--- a/include/BIOS/func/a20enable.nasm
+++ b/include/BIOS/func/a20enable.nasm
@@ -105,6 +105,7 @@ EnableA20:
    je EnableA20.endp         ; A20 is already enabled

    mov ax, 0x2403
+    clc                             ; clear carry
    int 0x15
    jc EnableA20.do_fallback_a20    ; carry = error...not supported?
    cmp ah, 0
@@ -121,6 +122,7 @@ EnableA20:
    ERROR STAGE2_A20_FAILED
 .do_bios_a20:
    mov ax, 0x2401
+    clc                             ; clear carry
    int 0x15
    jmp EnableA20.a20_check
 .do_fast_a20: