TomW - June 17, 2002

Just a few notes on getting a serial mouse working on the Tux. I don't use tinyx but have opted for a full implementation of debian-ARM on the IDE drive of my Tux. Getting the serial mouse working is not difficult, first you need an XF86Config file:

# **********************************************************************
# Refer to the XF86Config(4/5) man page for details about the format of
# this file.
# **********************************************************************

Section "Files"
    RgbPath	"/usr/X11R6/lib/X11/rgb"
    FontPath   "unix/:7100"
EndSection


# **********************************************************************
# Server flags section.
# **********************************************************************

Section "ServerFlags"
#    NoTrapSignals
#    DontZap
#    DontZoom
    AllowMouseOpenFail
EndSection

# **********************************************************************
# Keyboard section
# **********************************************************************

Section "Keyboard"
    Protocol    "Standard"
#    Protocol   "Xqueue"
    AutoRepeat  250 30
    #ServerNumLock
    LeftAlt        Meta
    RightAlt       Meta
    ScrollLock     Compose
    RightCtl       Control
#    XkbDisable
# These are the default XKB settings for XFree86
#    XkbRules    "xfree86"
#    XkbModel    "pc101"
#    XkbLayout   "us"
#    XkbVariant  ""
#    XkbOptions  ""
    XkbKeycodes     "xfree86"
    XkbTypes        "default"
    XkbCompat       "default"
    XkbSymbols      "us(pc105)"
    XkbGeometry     "pc"
    XkbRules        "xfree86"
    XkbModel        "pc105"
    XkbLayout       "us"
EndSection

# **********************************************************************
# Pointer section
# **********************************************************************

Section "Pointer"
    Protocol    "Microsoft"
    Device      "/dev/ttySA0"
#    ZAxisMapping 4 5
    Emulate3Buttons
    Emulate3Timeout    50
# ChordMiddle is an option for some 3-button Logitech mice
#    ChordMiddle
EndSection


# **********************************************************************
# Monitor section
# **********************************************************************

# Any number of monitor sections may be present

Section "Monitor"
 Identifier	"Primary-Monitor"
EndSection


# **********************************************************************
# Graphics device section
# **********************************************************************

Section "Device"
 Identifier     "fbdev"
 VendorName     "fbdev"
 BoardName      "fbdev"
EndSection


# **********************************************************************
# Screen sections
# **********************************************************************


# The Colour SVGA server

Section "Screen"
 Driver        "fbdev"
 Device        "fbdev"
 Monitor       "Primary-Monitor"
 SubSection "Display"
 Depth       8
 Modes       "default"
 EndSubSection
EndSection

Next, you need to patch the kernel to allow the RTS pin of the Aux port to output a positive voltage (idle state of RTS), this is a bug in serial_sa1100.c that it doesn't initialize the modem control lines (RTS):

--- linux/drivers/serial/serial_sa1100.c.old	Mon Jun 17 02:50:45 2002
+++ linux/drivers/serial/serial_sa1100.c	Mon Jun 17 02:51:21 2002
@@ -562,6 +562,8 @@
 	 */
 	PPDR |= PPC_TXD1 | PPC_TXD3;
 	PPSR |= PPC_TXD1 | PPC_TXD3;
+		/* make GPIO_19 output a positive voltage on RTS. */
+	GPDR |= GPIO_SSP_CLK; GPCR |= GPIO_SSP_CLK;
 }
 
 void __init sa1100_register_uart_fns(struct sa1100_port_fns *fns)

The mouse pointer on the screen does not move smoothly, it sort of "flutters" when you move it. I suspect that this is due to how the mouse pointer is drawn / managed by the frame buffer (XF68_FBDev).

I am not sure that tinyx will support a mouse, tinyx is a heavily hacked bit of source that was geared towards a specific use: the iPAQ. Since tinyx does not have an XF86Config file, I doubt that you can get a mouse working on it without adding more code to tinyx.