diff options
| -rw-r--r-- | memdisk/memdisk.asm | 40 |
1 files changed, 14 insertions, 26 deletions
diff --git a/memdisk/memdisk.asm b/memdisk/memdisk.asm index 1fd3329f..0d489614 100644 --- a/memdisk/memdisk.asm +++ b/memdisk/memdisk.asm @@ -630,38 +630,17 @@ bcopy: mov bx, real_int15_stub test byte [ConfigFlags], CONFIG_RAW|CONFIG_SAFEINT - jz .anymode + jz .anymode ; Always do the real INT 15h smsw ax ; Unprivileged! test al,01h - jnz .protmode + jnz .protmode ; Protmode -> do real INT 15h .realmode: - test byte [ConfigFlags], CONFIG_RAW - jnz .raw + ; Raw or Safeint mode, and we're in real mode... - ; We're in real mode with CONFIG_SAFEINT, invoke INT 15h - ; directly if the vector is unchanged, otherwise invoke - ; the *old* INT 15h vector. - - push ds - xor ax, ax - mov ds,ax - - cmp word [4*0x15], Int15Start - jne .changed - - mov ax, cs - cmp word [4*0x15+2], ax - jne .changed - - pop ds - jmp .anymode ; INT 15h unchanged, safe to execute - -.changed: ; INT 15h modified, execute *old* INT 15h - pop ds - mov bx, fake_int15_stub - jmp .anymode + test byte [ConfigFlags], CONFIG_SAFEINT + jnz .fakeint15 .raw: TRACER 'r' @@ -741,6 +720,15 @@ bcopy: popfd ; <A> jmp .done +.fakeint15: + ; We're in real mode with CONFIG_SAFEINT, invoke the + ; original INT 15h vector. We used to test for the + ; INT 15h vector being unchanged here, but that is + ; *us*; however, the test was wrong for years (always + ; negative) so instead of fixing the test do what we + ; tested and don't bother probing. + mov bx, fake_int15_stub + .protmode: TRACER 'p' .anymode: |