Changeset 39090 in vbox for trunk

Timestamp:

Oct 24, 2011 12:23:51 PM (13 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

74522

Message:

VBox/asmdefs.mac: COM_INIT fixes, untested.

File:

• trunk/include/VBox/asmdefs.mac (modified) (1 diff)

trunk/include/VBox/asmdefs.mac

@@ -70 +70 @@
 ; al and dx are wasted.
 ; @todo comport init doesn't quite work - therefore we no longer use this! :-/
+; @todo test again, it might work now...
 %macro COM_INIT 0
-    push    eax
-    push    edx
-
-    mov     dx, VBOX_UART_BASE + 3
-    mov     al, 80h
-    out     dx, al                      ; make DL register accessible
-
-    mov     dx, VBOX_UART_BASE
-    mov     ax, VBOX_UART_RATE
-    out     dx, ax                      ; write bps rate divisor
-
-    mov     dx, VBOX_UART_BASE + 3
-    mov     al, VBOX_UART_PARAMS
-    out     dx, al                      ; write parameters
-
-
-    xor     ax, ax
-    mov     dx, VBOX_UART_BASE + 4      ; disconnect the UART from the int line
-    out     dx, al
-
-    mov     dx, VBOX_UART_BASE + 1      ; disable UART ints
-    out     dx, al
-
-    mov     dx, VBOX_UART_BASE + 2      ; disable the fifos (old software relies on it)
-    out     dx, al
-
-    mov     dx, VBOX_UART_BASE
-    in      al, dx                      ; clear receiver
-    mov     dx, VBOX_UART_BASE + 5
-    in      al, dx                      ; clear line status
-    inc     dx
-    in      al, dx                      ; clear modem status
-
-    pop     edx
-    pop     eax
+        push    eax
+        push    edx
+
+        mov     dx, VBOX_UART_BASE + 2
+        mov     al, 0
+        out     dx, al                  ; Disable the fifos (old software relies on it)
+
+        mov     dx, VBOX_UART_BASE + 3
+        mov     al, 80h
+        out     dx, al                  ; make DL register accessible
+
+        mov     dx, VBOX_UART_BASE
+        mov     ax, VBOX_UART_RATE
+        out     dx, al                  ; write low bps rate divisor
+
+        mov     dx, VBOX_UART_BASE+1
+        xchg    al, ah
+        out     dx, al                  ; write high bps rate divisor
+
+        mov     dx, VBOX_UART_BASE + 3
+        mov     al, VBOX_UART_PARAMS
+        out     dx, al                  ; write parameters & lock divisor
+
+        mov     dx, VBOX_UART_BASE + 4  ; disconnect the UART from the int line
+        mov     al, 0
+        out     dx, al
+
+        mov     dx, VBOX_UART_BASE + 1  ; disable UART ints
+        out     dx, al
+
+        mov     dx, VBOX_UART_BASE
+        in      al, dx                  ; clear receiver
+        mov     dx, VBOX_UART_BASE + 5
+        in      al, dx                  ; clear line status
+        inc     dx
+        in      al, dx                  ; clear modem status
+        mov     dx, VBOX_UART_BASE + 2
+        in      al, dx                  ; clear interrupts (IIR)
+
+        pop     edx
+        pop     eax
 %endmacro