diff options
Diffstat (limited to 'ldlinux.asm')
| -rw-r--r-- | ldlinux.asm | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/ldlinux.asm b/ldlinux.asm index ecdcf3aa..d1a065c9 100644 --- a/ldlinux.asm +++ b/ldlinux.asm @@ -323,9 +323,11 @@ CursorRow resb 1 ; Cursor row for message file ScreenSize equ $ VidCols resb 1 ; Columns on screen-1 VidRows resb 1 ; Rows on screen-1 +FlowControl equ $ +FlowOutput resb 1 ; Outputs to assert for serial flow +FlowInput resb 1 ; Input bits for serial flow RetryCount resb 1 ; Used for disk access retries KbdFlags resb 1 ; Check for keyboard escapes -FlowControl resb 1 ; Serial port flow control LoadFlags resb 1 ; Loadflags from kernel A20Tries resb 1 ; Times until giving up on A20 FuncFlag resb 1 ; Escape sequences received from keyboard @@ -1284,7 +1286,7 @@ pc_serial: call getint ; "serial" command jc parse_config_2 call ungetc call getint - mov [FlowControl], byte 0 ; Default to no flow control + mov [FlowControl], word 0 ; Default to no flow control jc .nobaud .valid_baud: push ebx @@ -1292,7 +1294,9 @@ pc_serial: call getint ; "serial" command jnc .valid_flow xor bl,bl ; Default -> no flow control .valid_flow: - mov [FlowControl],bl + mov bh,bl + and bx,0F003h ; Valid bits + mov [FlowControl],bx pop ebx ; Baud rate jmp short .parse_baud .nobaud: @@ -1326,13 +1330,11 @@ pc_serial: call getint ; "serial" command xor al,al ; IRQ disable call slow_out - test byte [FlowControl],01h - jz .no_flow add dx,byte 3 ; DX -> MCR in al,dx - or al,03h ; DTR=1 RTS=1 + mov ah,[FlowOutput] ; DTR and RTS control + or al,ah ; Assert bits call slow_out -.no_flow: ; Show some life mov si,syslinux_banner @@ -3270,6 +3272,7 @@ write_serial: and bx,bx je .noserial push ax + mov ah,[FlowInput] .waitspace: ; Wait for space in transmit register lea dx,[bx+5] ; DX -> LSR @@ -3277,13 +3280,12 @@ write_serial: test al,20h jz .waitspace - ; Wait for CTS to become available if applicable - test byte [FlowControl], 01h - jz .no_flow + ; Wait for input flow control inc dx ; DX -> MSR in al,dx - test al,10h - jz .waitspace + and al,ah + cmp al,ah + jne .waitspace .no_flow: xchg dx,bx ; DX -> THR |