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Kludged Etch for the Psion 5mx (beta)
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Linux on the Psion 5mx A kludged linux
for the Psion 5mx
Based on Debian GNU/Linux 3.1 ARM port
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The Psion 5mx,
although now
over-shadowed by the new generation of PDA, is still a very capable
machine.
Using its own proprietary EPOC operating system, it provides a basic
organiser
for most every day needs, although development of the Psion and EPOC
has
ceased. Its use however, can be regenerated by the installation of the
Linux
OS. This allows the organiser to become a miniature, multi user,
multitasking,
network enabled UNIX
machine, which can be used for
many applications. Of course it has its limits, but for someone who is
familiar
with the Unix/Linux console tools it is surprising what can be
achieved. I
personally have used it to store contact details, keep notes, as a
training
tool, to browse the web, for E-mail and ICQ messages, and to write
reports and
catalogue information. It can be customised to the user's requirements
by
installing various applications. Above all it has a proper keyboard,
some thing
I have always found essential for data entry.
The community which has done the work to enable Linux to be run on the
Psion 5
and Psion 7 Netbook
series has the website
http://www.openpsion.org. Its members have taken the ARM processor port
of the Debian 3.1 Linux
distribution (Sarge),
and have hacked it and modified it to recognise
the
Psion hardware. This being essentially a work complete, all I have done
is to
add some useable applications and setup communications,
printing
and GUI to make a ready to go, functional
Linux
distribution. This can be downloaded
and installed by
the user himself or I can supply a
CD or a ready installed compact flash card.
The Psion 5mx
comes with
ROM, RAM and an optional flash disk (plug in card). The Operating
System (EPOC)
is stored in ROM, and on
power up, this boots and runs
(in RAM) with several built in, high quality applications. Data
generated by
application use, and newly installed (or written and compiled programs)
are
stored in RAM in an area which cannot then be used as program running
memory
(or are stored on the optional flash disk). All data in volatile memory
is held
there by the main batteries. Should the main batteries run down or
during
battery change, lithium back up battery takes over this job. There is a
mains
powered 6v DC adapter for the Psion 5mx which can be used where mains
power is
available. Should the back up battery and the main battery both fail,
all data
stored in RAM is lost (so it must be backed up fairly regularly). The
flash stored
data however is retained, and because the OS is contained in ROM this
remains
intact. In the unlikely event of a rogue program refusing to halt there
is a
hidden reset button, which has the same effect as a power loss. Due to
the
sharing of RAM for application data and program running the more data
stored
there the slower the machine becomes, until ultimately programs refuse
to load.
Linux running on the Psion 5mx is slightly different. The EPOC OS (in
ROM) is
still there and is used in some respect just the same as the BIOS in a
PC. It
boots the machine at first, and then a loader program (ARLO) is run
which
removes EPOC from running in RAM and loads the Linux kernel and runs
this in
RAM. ARLO provides the information to the kernel for where the root
partition
is, and then terminates, leaving Linux, it's
shell and
applications to use RAM as the kernel sees fit. User data is stored on
the
flash disk, which is treated exactly as if it was the hard disk of a
PC. On
reboot (cntrl menu
The root
partition pointed
to by ARLO for the kernel to mount and use as its file system is a true
partition of files and directories on an ext2 file system on the flash
disk. It
behaves in exactly the same way as a PC hard drive.
Some familiarity with Linux in general is helpful for getting it going
and
using it productively, but this Debian
Linux
pre-packaged distribution is fairly complete and ready to go so you can
give it
a try even if you haven’t tried Linux before.
Linux source code is freely distributed. Tens of thousands of programmers have reviewed the source code to improve performance, eliminate bugs, and strengthen security. No other operating system has ever undergone this level of review. This Open Source design has created most of the advantages listed below.
Linux has the best technical support available. Linux is supported by commercial distributors, consultants, and by a very active community of users and developers. In 1997, the Linux community was awarded InfoWorld's Product of the Year Award for Best Technical Support over all commercial software vendors.
Linux has no vendor lock-in. The availability of source code means that every user and support provider is empowered to get to the root of technical problems quickly and effectively. This contrasts sharply with proprietary operating systems, where even top-tier support providers must rely on the OS vendor for technical information and bug fixes.
Linux runs on a wide range of hardware. Most Linux systems are based on standard PC hardware, and Linux supports a very wide range of PC devices. However, it also supports a wide range of other computer types, including Alpha, Power PC, 680x0, SPARC, and Strong Arm processors, and system sizes ranging from PDA's (such as the Palm Pilot) to supercomputers constructed from clusters of systems (Beowulf clusters).
Linux is exceptionally stable. Properly configured, Linux systems will generally run until the hardware fails or the system is shut down. Continuous up-times of hundreds of days (up to a year or more) are not uncommon.
Linux has the tools and applications you need. Programs ranging from the market-dominating Apache web server to the powerful GIMP graphics editor are included in most Linux distributions. Free and commercial applications meet are available to meet most application needs.
Linux interoperates with many other types of computer systems. Linux communicates using the native networking protocols of Unix, Microsoft Windows 95/NT, IBM OS/2, Netware, and Macintosh systems and can also read and write disks and partitions from these and other operating systems.
Linux has a low total cost of ownership. Although the Linux learning curve is significant, the stability, design, and breadth of tools available for Linux result in very low ongoing operating costs.
Linux: ``all for one and one for all?? All changes one makes in Open Source software will benefit each and everyone, all over the world. Without exceptions or constraints.
Linux is fun!
The main reasons for wanting to use Linux on the Psion 5mx are:
a) You already use it on the desktop and would like your palmtop to match up.
b) You have a particular piece of software you want to run which is available for Linux but not EPOC.
c) The tragic demise of Psion means that EPOC is no longer being developed. Linux however is under continual development and the excellent Psion hardware need not be wasted.
d) Linux is very stable and has a huge software base. All the software included here is free software (as in freedom, not cost), so you can change it if you want or need to - this gives you a flexibility you don’t get with a proprietary OS like EPOC. On the other hand Linux is more resource-intensive than EPOC. Whilst you can run it on a bare 5mx you can’t do much in the RAM available - it needs a Compact Flash card to be able to make a capable system with more than a couple of applications. The Psion PDA,s are better suited than many to running Linux because they have real keyboards, on most other PDA’s these are an extra. Its main draw back is it only has a greyscale screen, although it is a good size.
Most of the
Psion 5mx hardware
is supported, the exceptions being the custom icons around the screen
for the
EPOC applications and menus. Also the dictaphone
buttons are not assigned, although they do generate strings. The
communications
set up is good and very useable for IrDA
as well as
the serial port, as is the sleep mode and touch screen. Sound is
supported with
the 2.4.19 kernel and the 2.4.27 modular kernel. It provides an easy
way to get
Linux on your Psion 5mx and try it out or use it for a specific purpose.
The PsiLinux community
have ported the Linux kernel
to the Series 5mx, 5mx Pro and Revo
(but not the
series 3), and created ARLO (the boot loader) and various distributions
(sets
of files and applications) designed for use with or without Compact
Flash.
Kludged Linux
requires a
512MB Compact Flash card. It contains all the basic elements of a Linux
system
like bash, vi, grep,
top, netcat,
cat, more, man, ppp,
telnet, ssh,
ftp, micq, the X window
system with the matchbox
window manager to give a simple graphical environment, mc, pine, pico, dillo
(the ssl patched
version), xedit, editres, xcalc,
antiword, minicom, gAcc,
Ted (an rtf and pdf
word
processor), lout and halibut the text formatters (to produce
postscript, pdf and
html documents) and gv
(to display ps and pdf documents).
The gcc compiler is
included which works but is very
slow and may over stretch resources in some cases. The print spooler lpd is included with magicifilter
to allow printing of plain text, postscript and pdf
to certain postscript enabled printers. The distribution also includes
running telnetd, ftpd and httpd
servers. Kludged Linux is based on the ‘Sarge Book’ dpkg-based system by
Brian Dushaw, which
itself is derived from the Debian
GNU Linux ARM port, modified to run on the psion
hardware by the psilinux
community. There are
thousands of Debian ARM
packages (*arm.deb)
available, many of which can be run on your Psion.
Kludged Linux
has a number
of features which make it useful:
• An up to date GNU/Linux system based on Linux kernel 2.4.27
and glibc 2.2
• A very simple but effective package manager (dpkg).
• Carefully selected packages which have only been included if
they are useful.
• A well set up communications to a desktop machine / modem /
IRDA mobile
phone.
• A simple but still useable window manager with very low
demand on resources.
Processor
32-bit ARM 710T CPU (RISC based), running at 36.864 MHz
Internal Memory
16 MB RAM
Internal Memory
10 MB ROM (5mx)
Removable Disk Type
Type I Compact Flash (CF) Disks
Display Resolution
640x240 (Half VGA)
Display Type
Monochrome touch screen (16 shades)
Default OS
EPOC (32 bit, multitasking)
Serial Ports
Standard RS232 and SIR Infrared; up to 115200 baud
Power
2 AA batteries, backed up by a CR2032 lithium battery
Sound
1/2 W, 8 Ohm loudspeaker
Microphone
electret with active
gain control
Keyboard
53 key, QWERTY layout
Size
172x89x24 mm
Weight
350g (with batteries)
Operating Temperature
0 to 40 C - and it really is likely to break if turned on below -5 C
EPOC stores
its data and
applications (on drive C:)
in RAM. EPOC itself lives
in ROM on the 5mx.
When Linux boots it takes over the RAM and thus erases anything
previously
there.
The Linux system can be halted or rebooted by the reboot command. This returns
the
machine to EPOC and on doing this the Psion automatically runs the
arlo.exe
program (giving the boot menu) by a file /system/data/wsini.ini
If the Compact flash is to be removed or the batteries changed, then
power off
the machine during the 5 seconds it displays this menu using (Fn
– off) and
then do it. After the compact flash has been removed, then power back
on and
the machine will start up into EPOC as if it had just had a hard reset.
The
Space left on the compact flash card containing arlo.exe etc. is
visible in
EPOC as D: drive and Linux as /msdos.
This space can
be used by both to store/transfer files.
You will need:
1. A Psion 5mx 16M (not the Psion 5mx pro 32M)
2. A Compact Flash card of 1G or
larger (this CF card must be recogniseable by the Psion in EPOC, some are not.)
3. A CF card to PCMCIA
adapter (for use with a laptop) or CF card to USB adapter
4. A PC or laptop running Linux
although this
could be a live CD distro
such as Knoppix , SLAX or Puppy Linux
5. A CD containing the current ksfxxxx.tgz
file and the files and directories to boot the kernel.
6. Fit the flash disk into the Adapter and plug it into the machine
running Linux.
7. Do not mount the drive which should show as an IDE drive (perhaps
/dev/hde
)
8. Type fdisk /dev/hde then
type p to show the disk partitions status as it is now (which should be
/dev/hde1 as vfat)
d to delete the current partition, and delete partition 1
n for a new partition.
p for primary partition
1 for partition hde1
for size choose 8M for hde1 and make it bootable (a) and type 4 (vfat) (t)
n for new partition
p for primary
2 for partition hde2
use all remaining size and make it type 83 (Linux native) (t)
p again to check the table is correct
w to write the table to disk.
q to quit.
9. Having prepared the disk partitions we now format both these
partitions.
mkfs.ext2 /dev/hde2 and then mkfs.msdos
/dev/hde1
mount -t vfat /dev/hde1
/mnt/hde1
mount -t ext2 /dev/hde2 /mnt/hde2 (assuming both /mnt/hde1 and
/mnt/hde2 exist)
cd /mnt/hde2
ls (this should show a
subdirectory listed lost+found)
tar -zxvf /path to the ksfxxxx.tgz
file (this will take several minutes and you should see the contents of
the tar
file being uncompressed and a file structure being written to the flash
disk.)
10. When it has finished and returned to the prompt then umount
/dev/hde2 and then copy over the files and directories in the folder
(files) on
the CD as they are. Then umount
/dev/hde1 and remove
the Flash disk
Installation is now complete, insert the card into the psion and navigate to D:\arlo\arlo.exe
using the EPOC system and
double click on arlo.exe to run it. If all went well the Psion 5mx
should boot
to a login prompt.
Login as
root with root as the password.
Set the date and time by typing setdate
then follow instructions.
Other users can be added by the adduser
command. It
would be a good idea to password
protect the root
account using the passwd
command if you are storing
any private information.
Next setup ppp.
Either use the pppconfig
command: Follow through the instruction steps but do not auto detect
the modem
– it must be manually set as /dev/ttyAM1 for the comm
port or /dev/ircomm0 for an IrDA
modem.
Alternatively you can use wvdial:
First connect your
modem, (wvdial is a
little more intelligent and so
will auto detect the modem). If an IrDA
modem is used
then turn it on and type iron to connect the IrDA.
Then run wvdialconf
/etc/wvdial.conf
to find the modem. After the modem has been detected, then the
/etc/wvdial.conf can be
edited for
:-
ISP phone number
Login name
Password.
After ppp has been
setup using pppconfig,
the command pon starts
the dial up connection, and poff
stops it.
To use the infra red port to connect to an IrDA
mobile phone it must have a proper modem built in such as the Sony
Ericsson's. An infrared modem (such as the Psion dacom
travel modem) can be used. Put /dev/ircomm0 as the port in place of the
/dev/ttyAM1 (the serial port) for minicom
or pppconfig.
To enable the port type iron to
disable the port type iroff.
To test if the other end port is found
after the iron commands is run, type ifconfig
which
will show local irda0 interface (and traffic) and then cat /proc/net/IrDA/discovery to show some
details about the remote
equipment. Then for instance after configuring ppp,
you can connect to your dial up ISP via an IrDA
mobile phone by typing iron and then pon.
At time to
disconnect, type poff
then iroff.
For wvdial switch
on/off the infrared port and then
run wvdial to connect.
Note. You can not telnet or ftp into the Psion using the root logon,
you must
use an ordinary user account, after this however you can su
to the root account.
Most of the PC keyboard functions have been met, but the 'F1
– F10' keys are
achieved by Esc 1 – Esc 0, '` (back tick)' by
Typing reset resets the console display, clear clears it.
Terminals can be switched by menu 1, menu 2 etc. (multi user but only 3
user
consoles are set up - come on it is only a PDA). You can however,
telnet in to
the Psion over the serial link (using PPP), and have many sessions
running at
the same time from a PC as a remote terminal.
Communications to a Linux PC is done using PPP. Copy
over the
files in the PC directory of the CD onto your Linux PC and put pcon and pcoff
into /usr/bin on your
Linux PC.
Add lines:
10.0.2.1 pc
10.0.2.2 psion
to the PC's /etc/hosts file.
Then to communicate between the Psion and the PC connect using the
serial cable
to PC com1 and type pcon
on the PC and pcon on
the Psion. The two are then connected by TCP/IP. use
ftp or telnet ssh to
talk to
each other but note, user accounts must be set up on each as you cannot
ssh telnet or
ftp using
the root as a user normally. So for
instance typing telnet pc on the Psion will give you a console login
for the PC
and vice versa. If the PC is running a web server you can browse its
pages
using the dillo browser.
pcoff
on both the PC and
Psion ends the connection.
I
found the dial up
connection using my mobile phone (IRDA modem to the psion) unbearably
slow so I used my PC as a router to connect over my broadband
connection, with the psion connected to the PC using ppp over a serial
lead. I have included the firewall configuration script (firewall.sh)
which was used to set up internet connection sharing on the PC in
files.zip. The PC I used was running Puppy
Linux
V2.16 ( I have included an
iso for this live CD on
the Kludged Sarge CD) and this distribution already has the script built in, but
most distributions which have iptables installed should work with this
script as well, the known exceptions being Debian and Ubuntu, neither of which I could get to work. To run
under DSL you must symlink /etc/rc.d to /etc/init.d and then make a file
rc.local in this linked directory - type commands ln -s /etc/init.d
/etc/rc.d and then touch /etc/init.d/rc.local - (A
brutal hack, its not called Kludged Linux for nothing).
The PC I used was connected
to a broadband adsl router with eth0
(but any connection should work, perhaps wlan0 if the PC has a
wireless connection to a router, type ifconfig -a to
see all your interfaces).
To start the
graphical
environment (X) type xinit.
First the screen fills
with a hatched grey
pattern with a cross in the
middle for a few seconds, then
the normal matchbox
screen is displayed.
Matchbox is a ’window manager’ optimised for
small-screen devices. It does not have overlapping windows like most
desktop
window managers - instead each application gets the whole display and
you can
easily flip between the running applications. An application launcher
menu is
also provided, much like Window’s ’Start’
button. Switching between running
apps is done using either the drop down menu in the top left hand
corner of the
display or the left/right buttons on the top right (the buttons go on
to the next
app in order until you get back to the one you started on). There are a number of Matchbox applets
which if run appear on the
bottom bar. By default the window manager runs a CPU Monitor, clock and
the
’Menu’ application launcher. These icons appear
from left to right on the
bottom bar. The square in the very bottom left hand corner shrinks the
bottom
bar. Tapping on the shrunken bar brings it back to full size.
The launcher button near the bottom left hand corner is labeled
’Menu’. Click
on this to get a list of
applications. Note that there are many more command-line programs
installed
which do not have entries here - you need to run them at a command
line. Below
we will list the most significant programs.
To the left of the Menu applet and clock is the CPU monitor. This
displays the
current percentage of CPU time the system is using in the form of a
scrolling
graph. The bars are lighter-coloured
up from the
bottom. This monitor is very useful for determining if the system is
busy or an
application is starting up slowly; some apps take a very long time to
start on
the underpowered ARM7 of the Psion 5mx - up to 30 seconds for many GUI
applications, for example. Matchbox is designed to work with a
single-button
mouse / pen / touch screen interface which makes life easier on the
Psion.
However many UNIX applications assume you have a 3-button mouse, or at
least a
2-button one, so it is useful to be able to generate these other two
buttons.
To use the pointer as a mouse, cntrl
3 gives right
click, cntrl 1 gives
left click and cntrl 2
gives middle click.
Xwindows can be exited
to the console command prompt
by cntrl-menu-del.
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Application |
Name and link to description |
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| Word Processors / text editors | Ted vi pico | |
| ps / pdf viewer | gv | |
| Type Setter | lout
halibut
antiword |
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Spreadsheet |
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File Manager |
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Browser |
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| E Mail | pine | |
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Serial Communications |
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Servers |
ssh telnetd ftpd lpd micro httpd |
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Networking |
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Database/PIM |
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Maths |
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Games |
Xkill bill and text based games in /usr/games |
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For E mail, pine can be used to directly use your pop mailbox as its
“Inbox
Folder” by using the following configuration setup:
personal-name = your name
user-id
= popuserid
user-domain =
yourisp.com
smtp-server
=
smtp.yourisp.com
nntp-server =
nntp.yourisp.com
inbox-path
= {pop.yourisp.com/pop3/user=popuserid}inbox
First you
should login as
another user, pine sets itself up to send mail as user@domain
so for instant if my ISP email address is adrian@isp.com then I create
a user
account
The gcc compiler suite
is included so programs
obtained as source code can be compiled for the ARM based system,
however be
warned that the built in 16M of RAM may be insufficient, so to
successfully
compile an application it may be necessary to set up some sort of swap
partition.
(Section 3)
For applications help, use the help in the matchbox menu, or use the console man command, there are also some links at http://www.ajwells.net.
System mounts
are specified
in /etc/fstab and are
mounted during system startup:
Default System Mounts
Mount Point
Mounted Filesystem Description
/
/dev/hda2
Second (Linux) partition on CF card
/msdos
/dev/hda1 First
(EPOC) partition on CF card
/proc
proc Kernel data
filesystem
The EPOC partition uses the same format as DOS/Windows hard disk - the
FAT filesystem.
Mounting it as /msdos
means that you can access any files you put on it from Linux as well as
EPOC.
This proves a useful way to transfer files.
The Psion 5mx
keyboard is
very different from the standard PC keyboard. We use the following
special key
assignments (
| PSION | PC |
|
Fn |
Alt
Gr |
|
Menu |
Alt |
|
Fn-T |
|
(pipe) |
|
Fn-Del
|
‘
(backtick) |
|
Menu-1,
Menu-2 etc |
Alt-F1
(VT1) Alt-F2 (VT2) etc |
|
Ctrl-Menu-, |
SysRq |
|
Ctrl-Menu-Del |
Ctrl-Alt-Backspace
(Halt Xserver) |
|
Fn-Space |
Backlight
on/off |
|
Fn-Esc |
Sleep
on/off |
|
Fn-M |
Reduce
Contrast |
|
Fn-. |
Increase
contrast |
|
Esc-1,
Esc-2 etc |
F1,
F2 etc |
Linux provides several virtual terminals that can be selected using
Menu-1,
Menu-2, etc. You can go back and forth between the various screens at
will, and
so multi-process. VT7 contains the X graphics display. Kludged Linux has 3 virtual terminals
(this saves memory over the
usual 6). /etc/inittab
controls how many VTs
are started.
Advanced Info: The command dumpkeys
> filename
will dump out a set of key mappings that you can take a look at. loadkeys
filename will then load
in that keymap (with
whatever modifications you have
made to it). If you have trouble saving your special keys
functionality, you
can comment out or delete the lines for the special keys (e.g., the
space key)
to preserve their special functions (e.g., the backlight).
The Psion 5mx
screen can
run in either 4-grey (2bpp - bits per pixel) or 16-grey (4bpp) modes.
Note that some graphical applications will not work at all on a screen
of less
than 256 colours/greys,
so these will need
modification to run on the Psion.
This distribution starts up in 4bpp, and the Xserver
needs this mode to run.
Use fbset
-a 2bpp (or fbset -a
mono), fbset -a 4bpp,
to
set the framebuffer
depth if needed.
The Esc/On key
will take
your Psion in and out of sleep mode just as it does for EPOC. If this
doesn’t
work then by far the most likely reason is the irattach
daemon (which deals with infrared connections). If this is running it
wakes the
machine up again immediately so you can’t sleep. Until this
is fixed you need
to kill it in order to sleep the machine. Do this with iroff.
The Linux
system can be halted or rebooted
by the command reboot which shuts linux down and returns the machine to
EPOC and on doing this the Psion automatically runs the
arlo.exe
program (giving the boot menu) by a file /system/data/wsini.ini. Remove
power / batteries from the machine during this menu display. The
shutdown command appears to ungracefully halt the OS and does not
unmount the partitions before system halt.
After each reboot the time and date lag by the duration that the system
was
down as to keep the time approximately correct on reboot time is
written to a
file which is read again on startup.
Hence occasionally
after several reboots or a lengthy shutdown, the time with need to be
adjusted
using the script 'setdate'.
If the Compact flash is to be removed or the batteries changed, then
power off
the machine during the 5 seconds
it displays
this menu using (Fn – off) and then do it. If you replace the
CF card and power
on, the menu may continue as normal, or you may need to select the exit
option
from the menu and try again.
If your machine is hung for some reason and you need to reset it
manually, then:
Open the backup battery door and locate the small copper coloured
circle near
the battery, using a partly unfolded paperclip or similar, gently press
in the
copper coloured circle. Now close the backup battery door, and hit the
Esc/on
key. The machine should beep twice and then display the Psion splash
screen. On
the 5mx there is a delay while EPOC reads its system out of ROM and
reloads it
into RAM.
Note: While pressing the Esc/on key you may need to holding down both
shift
keys to encourage EPOC to
clear all memory, but this is not usually needed.
If the Compact
Flash disk
has been corrupted it can cause the reboot to fail - remove the disk to
allow
EPOC to start, and then reinstall your system to the disk.
Packages can
be installed from
the Debian Sarge packages with varying
degrees of
success. As Sarge has now been superceded these packages are only available from some vendors selling debian CD's
(arm architecture), or debian archives such as (here seems to work at present). To install a package xxx.deb
type
dpkg -i xxx.deb
To remove a package type
dpkg -r xxx or to
completely remove all config
files dpkg
–purge xxx
The apt package has been removed to save disk space. It needed more
than 16M
RAM to run anyway unfortunately.
There are also some arm binaries available here http://netwinder.oregonstate.edu/pub/netwinder/RPMS/nw/9/
But these are rpm files and would need to be extracted using some other Linux machine and then installed
manually.
The kernel
provides various
ways of interacting with the special features of the Psion hardware.
For
example it flashes the ’recording’ LED during CPU
activity so you can see how
much work the system is doing by looking at the flash rate. The LED
normally
flashes quickly. When it is running flat out the LED is almost
permanently on. When sleeping the LED
doesn’t flash at all. Most
of the other items such as the case opening status, and
backlight, and accessed via the /proc filesystem.
This gives you access to an enormous amount of information about the
kernel and
running application, networking status etc, but the bit which concerns
the
Psion hardware is the /proc/psionw
directory. The
name comes from Psion Windermere, which is the codename for the
5mx/5mx-Pro
hardware. In here we have the following files:
backlight
State of the backlight - 1 is on, 0 is off. Read/write.
Writing 1 will turn the backlight on ,
writing 0 will
turn
if off.
case
State of the case switch - 1 is open, 0 is closed. This is read-only.
contrast
Current contrast setting for the display. Read-only.
cpu
CPU is the CPU speed in Mhz.
Read-only.
lcd
Display power status - 1 is on, 0 is off. Read/write.
Writing 0 will turn the display off, writing 1 will turn it
back on.
mains
Mains power status - 1 is mains present, 0 is mains disconnected.
Read-only
sleep
Sleep status - 1 is sleeping, 0 is running. Read/write.
Writing 1 to this file will cause the machine to sleep.
state
uart1
uart2
These all contain 0 or 1 except contrast and cpu.
Set
a writeable value to 1
like this: echo "1"
> backlight
Sound is
supported. cat /dev/dsp > soundfile.al will record from
the microphone and cat soundfile.al
> /dev/dsp will
play it. A mixer will need to be installed to vary volume. There is a
sample
sound in the matchbox menu.
