Fix up handling of serial port "raw hardware" driver; still needs to be

given a trap when boot fails (this would be good for the main code as
well.)  Removed bogus \n in version file.  Updated TODO for serial port.

diff --git a/TODO b/TODO
index 7abb356..8d792c7 100644 (file)
--- a/TODO
+++ b/TODO
@@ -1,3 +1,9 @@
+- Serial support:
+  - Need ^C/Esc to work
+  - Error messages need to be redirected to the serial port
+  - Clean up the option
+  - Disable serial support (or do something at least) on timeout
+  - Straight to hardware?
 - Cleaned up documentation, with a real man page.
 - Support for clusters larger than 16K.  This would require changing
   a lot of the SYSLINUX internals so we can read partial clusters;

diff --git a/ldlinux.asm b/ldlinux.asm
index 47d77fe..cab2f3f 100644 (file)
--- a/ldlinux.asm
+++ b/ldlinux.asm
@@ -34,7 +34,7 @@ max_cmd_len   equ 255                 ; Must be odd; 255 is the kernel limit
 retry_count    equ 6                   ; How patient are we with the disk?
 HIGHMEM_MAX    equ 038000000h          ; Highest address for an initrd
 DEFAULT_BAUD   equ 9600                ; Default baud rate for serial port
-
+BAUD_DIVISOR   equ 115200              ; Serial port parameter
 ;
 ; Should be updated with every release to avoid bootsector/SYS file mismatch
 ;
@@ -282,9 +282,11 @@ debug_okay:        mov si,trackbuf+0bh
                nop
                jmp debugentrypt
 %endif
+               absolute 0400h
+serial_base    resw 4                  ; Base addresses for 4 serial ports
 
                 absolute 0484h
-BIOS_vidrows    resb 1                    ; Number of screen rows
+BIOS_vidrows    resb 1                 ; Number of screen rows
 
 ;
 ; Memory below this point is reserved for the BIOS and the MBR
@@ -345,7 +347,6 @@ NextCharJump    resw 1                      ; Routine to interpret next print char
 SetupSecs      resw 1                  ; Number of setup sectors
 SavedSP                resw 1                  ; Our SP while running a COMBOOT image
 A20Test                resw 1                  ; Counter for testing status of A20
-SerialPort     resw 1                  ; Serial port no (or -1 for no serial port)
 TextAttrBX      equ $
 TextAttribute   resb 1                 ; Text attribute for message file
 TextPage        resb 1                 ; Active display page
@@ -1287,23 +1288,47 @@ pc_implicit:    call getint                     ; "implicit" command
 
 pc_serial:     call getint                     ; "serial" command
                jc parse_config_2
-               mov [SerialPort],bx
+               push bx                         ; Serial port #
                call skipspace
+               jc parse_config_2
+               call ungetc
                call getint
-;              jnc .valid_baud
-;              mov ebx,DEFAULT_BAUD            ; No baud rate given
-;.valid_baud:  mov ecx,9600
+               jnc .valid_baud
+               mov ebx,DEFAULT_BAUD            ; No baud rate given
+.valid_baud:   pop di                          ; Serial port #
+               cmp ebx,byte 75
+               jb parse_config_2               ; < 75 baud == bogus
+               mov eax,BAUD_DIVISOR
+               cdq
+               div ebx
+               push ax                         ; Baud rate divisor
+               mov dx,di
+               shl di,1
+               mov ax,[di+serial_base]
+               mov [SerialPort],ax
+               push ax                         ; Serial port base
                mov ax,00e3h                    ; INT 14h init parameters
-;.baud_loop:   cmp ebx,ecx
-;              jae .this_baud
-;              sub al,020h
-;              shr ecx,1
-;              jmp short .baud_loop
-.this_baud:    mov dx,[SerialPort]
-               int 14h                         ; Initialize serial port
+               int 14h                         ; Init serial port
+               pop bx                          ; Serial port base
+               lea dx,[bx+3]
+               mov al,83h                      ; Enable DLAB
+               call slow_out
+               pop ax                          ; Divisor
+               mov dx,bx
+               call slow_out
+               inc dx
+               mov al,ah
+               call slow_out
+               mov al,03h                      ; Disable DLAB
+               add dx,byte 2
+               call slow_out
+               sub dx,byte 2
+               xor al,al                       ; IRQ disable
+               call slow_out
+
                mov al,'>'
                call write_serial
-               jmp short parse_config_2                
+               jmp short parse_config_3
 
 pc_fkey:       sub ah,'1'
                jnb pc_fkey1
@@ -1322,7 +1347,7 @@ pc_fkey1: xor cx,cx
                shl di,4                        ; Multiply number by 16
                add di,FKeyName
                call mangle_name                ; Mangle file name
-               jmp short parse_config_2
+               jmp short parse_config_3
 
 pc_label:      call commit_vk                  ; Commit any current vkernel
                mov di,trackbuf                 ; Get virtual filename
@@ -1433,11 +1458,11 @@ tick_loop:      push dx
                int 16h
                jnz get_char_pop
                mov dx,[SerialPort]             ; Check for serial port input
-               cmp dx,byte -1
+               and dx,dx
                je .noserial
-               mov ax,0300h
-               int 14h
-               test ah,1                       ; Receive data ready
+               add dx,byte 5
+               in al,dx
+               test al,1                       ; Receive data ready
                jnz get_char_pop
 .noserial:     xor ax,ax
                int 1Ah                         ; Get time "of day"
@@ -1453,16 +1478,15 @@ get_char:       mov ah,1                        ; Keyboard char ready?
                int 16h
                jnz get_kbd
                mov dx,[SerialPort]             ; Serial port input?
-               cmp dx,byte -1
-               je get_char
-               mov ax,0300h
-               int 14h
-               test ah,1
+               and dx,dx
+               jz get_char
+               add dx,byte 5
+               in al,dx
+               test al,1
                jz get_char
 
-get_serial:    mov ax,0200h                    ; Get char from serial port
-               mov dx,[SerialPort]
-               int 14h
+get_serial:    mov dx,[SerialPort]             ; Valid only when we have already
+               in al,dx                        ; tested for input!!
                jmp short got_ascii
 
 get_kbd:       xor ax,ax                       ; Get char
@@ -1512,7 +1536,7 @@ set_func_flag:
 
 ctrl_f_0:      add al,10                       ; <Ctrl-F>0 == F10
 ctrl_f:                push di
-               sub al,'0'
+               sub al,'1'
                xor ah,ah
                jmp short show_help
 
@@ -2123,7 +2147,7 @@ root_not_floppy:
 kill_motor:
                mov dx,03F2h
                xor al,al
-               out dx,al
+               call slow_out
 ;
 ; Now we're as close to be done as we can be and still use our normal
 ; routines, print a CRLF to end the row of dots
@@ -2421,6 +2445,8 @@ bcopy:            push eax
 %define IO_DELAY_PORT  80h             ; Invalid port (we hope!)
 %define delaytime      1024            ; 4 x ISA bus cycles (@ 1.5 µs)
 
+slow_out:      out dx, al              ; Fall through
+
 _io_delay:     push ax
                in ax,IO_DELAY_PORT
                in ax,IO_DELAY_PORT
@@ -2598,11 +2624,12 @@ abort_check:
 ac1:
                mov ah,1                        ; Check for pending keystroke
                int 16h
-                jz ac_ret                       ; If no pending keystroke
+                jz ac_nokbd                     ; If no pending keystroke
                xor ax,ax                       ; Load pending keystroke
                int 16h
                mov bx,KbdMap
                xlatb
+ac_char:                                       ; Character received
                cmp al,27                       ; <ESC> aborts (DOS geeks)
                je ac2
                cmp al,3                        ; So does Ctrl-C (UNIX geeks)
@@ -2630,6 +2657,20 @@ abort_load:
                 call cwritestr                  ; Expects SI -> error msg
 al_ok:          jmp enter_command               ; Return to command prompt
 ;
+; Check for serial port abort
+;
+ac_nokbd:
+               mov bx,[SerialPort]
+               and bx,bx
+               jz ac_ret                       ; No serial port
+               lea dx,[bx+5]
+               in al,dx
+               and al,01h
+               jz ac_ret                       ; Nothing on the serial port
+               xchg dx,bx
+               in al,dx
+               jmp short ac_char               ; Character received!
+;
 ; End of abort_check
 ;
 ac_ret:         popa
@@ -2943,11 +2984,17 @@ msg_color_bad:
 ;
 write_serial:
                pusha
-               mov dx,[SerialPort]
-               cmp dx,byte -1
+               mov bx,[SerialPort]
+               and bx,bx
                je .noserial
-               mov ah,01h
-               int 14h
+               push ax
+.waitspace:    lea dx,[bx+5]                   ; Wait for space in transmit reg
+               in al,dx
+               test al,20h
+               jz .waitspace
+               xchg dx,bx
+               pop ax
+               call slow_out                   ; Send data
 .noserial:     popa
                ret
 
@@ -3571,6 +3618,7 @@ initrd_ptr        dw 0                    ; Initial ramdisk pointer/flag
 VKernelCtr     dw 0                    ; Number of registered vkernels
 ForcePrompt    dw 0                    ; Force prompt
 AllowImplicit   dw 1                    ; Allow implicit kernels
+SerialPort     dw 0                    ; Serial port base (or 0 for no serial port)
 ;
 ; Stuff for the command line; we do some trickery here with equ to avoid
 ; tons of zeros appended to our file and wasting space

diff --git a/version b/version
index ec8538e..24c87c5 100644 (file)
--- a/version
+++ b/version
@@ -1,2 +1 @@
 1.45
-