booting101

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

The bitsy comes with Wince.  To get to Plan 9, you will need a serial cable,
a Windows machine with a serial interface, the CDROM that comes with the bitsy,
and a Plan 9 machine with a serial interface.  The Windows machine is used to
get the Linux boot loader onto the bitsy (and to save away wince, if you so
desire).  The Plan 9 machine is used to get the plan 9 kernel and a read only
file system onto the bitsy.

0.  charge up the bitsy.

1.  go to
	ftp://ftp.handhelds.org/pub/linux/compaq/ipaq/stable/install.html
Get the latest version of the Linux "osloader" and "bootldr" programs
(we have tried versions 1.3.0 and 0000-2.14.8, respectively; newest
versions seem not to allow you to suspend your bitsy due to a bug
which is probably ours).  You can find them all at
www.collyer.net/who/geoff/9/bitsy/.

2.  Use ActiveSync to copy osloader and bootldr to the bitsy.  Copy or
rename the bootldr binary to "bootldr" on Windows, then copy it to the
bitsy; trying to rename it on WinCE won't produce the right result.

Steps 3 - 7 may work on a Pocket PC bitsy, but see Steps 3a - 7a
if they don't or if you have a Pocket PC 2002 bitsy.

3.  Run osloader by clicking on it under the WinCE File Explorer

4.  Use osloader to save your WinCE flash away.  This takes a while,
as it's 16MB over a 115,200 baud line.

5.  Select "Run" from the osloader menu.  Ignore "Run from RAM"; it's
not needed.

6.  At this point, the bitsy's screen turns blank, but you can still
talk to the bitsy over its serial port.  The serial port is connected
to the OS loader's terminal program.  On Windows, you have to exit
ActiveSync before the serial port is available for a terminal program.
I moved the bitsy and its cable over to a Plan 9 machine and connected
using "con -b 115200 /dev/eia[01]" to talk to the console.  The
command "help" lists the OS loader's commands.

7.  Now you need to download the BOOT loader program into flash (right
now, you're only running the OS loader program out of RAM; rebooting
will get you back to WinCE).  In the con window, "load bootldr" to the
bitsy.  It will indicate that it's starting an xmodem download.
Under con, type "Ctrl-\" to get a ">>>" prompt.  At this prompt, you
want to run Plan 9's xms program to pipe the bootldr program to the
bitsy.  For example, to download /tmp/bootldr, type "!xms /tmp/bootldr".

If this step works successfully, the OS loader will print out some sort
of OK checksum message.

If you have a Pocket PC 2002 or steps 3 - 7 above didn't work for you,
try 3a - 7a.

3a.  Copy BootBlaster (also) to the bitsy via ActiveSync.

4a.  Save your flash by running osloader and selecting "Flash->Save to
File".  As it produces 4MB files, use ActiveSync to copy them off the
bitsy.

5a.  Move the bitsy and its cable over to a Plan 9 machine and connect
using "con -b 115200 /dev/eia[01]" to talk to the console.

6a.  Run BootBlaster by clicking on it under the WinCE File Explorer.

7a.  Select "Program"; it should copy "bootldr" into your flash in
about 15 seconds.

8.  Reboot your bitsy (either cycle the power or use the reset
switch).  The new boot loader runs out of Flash.  You'll get the linux
penguin splash screen and a bunch of options triggered by buttons.
Pick the one that gets you to the boot loader.

9.  Make the partitions you need in the bitsy's flash, type, using
the con program:
	partition reset
	partition define bootldr 0x000000 0x040000 2
	partition define params 0x040000 0x040000 0
	partition define kernel 0x080000 0x0c0000 0
	partition define user 0x140000 0x0c0000 0
	partition define ramdisk 0x200000 0x600000 0
	partition define fs 0x800000 0x800000 0
	params save

These are the partitions as shown by partition show:
	boot> partition show
	argv[1]=partition
	npartitions=00000006
	bootldr
	  base: 00000000
	  size: 00040000
	 flags: 00000002
	params
	  base: 00040000
	  size: 00040000
	 flags: 00000000
	kernel
	  base: 00080000
	  size: 000C0000
	 flags: 00000000
	user
	  base: 00140000
	  size: 000C0000
	 flags: 00000000
	ramdisk
	  base: 00200000
	  size: 00600000
	 flags: 00000000
	fs
	  base: 00800000
	  size: 00800000
	 flags: 00000000

After each line you'll get a message like `defining partition: params'.
Different versions of the bootloader predefine different partitions.
The bootldr partition is usually predefined, so you don't have to remake
that.  You may have to delete one or two partitions.  The command is
	partition delete <name>
Make sure the partition layout is as given above; some of this knowledge is
built into the kernel.

10. Before you can fill the new partitions with a kernel and a read-only
file system, you'll have to make them.  In the directory /sys/src/9/bitsy,
type mk and mk paqdisk.  Before mk-ing paqdisk, make sure you have all
the necessary arm binaries installed in /arm and examine the file
paqfiles/mfs to see what you need to change for connecting to your local
file servers.

11.  Now you can type "load kernel".  The boot loader will prompt for
another xmodem download.  Again escape using "Ctrl-\", then use
"!xms /sys/src/9/bitsy/9bitsy" (or "!xms /arm/9bitsy" if you've already
installed it).

12.  Download the ramdisk, using "load ramdisk" and
"!xms /sys/src/9/bitsy/paqdisk" (or "!xms /arm/paqdisk" if you've already
installed it), similarly to 10, above.

13. Type `boot' or `boot flash' depending on your version of the boot loader.
If you need the latter, you may want to

	set boot_type flash
	params save

to make boot flash the default.

You'll get a Dutch flag (or a French one, if you hold the iPaq the wrong way),
then the boot screen will say, on the serial port, thus in your con window:

	root is from [paq]:

Just wait a while or hit enter in the con window and it'll continue.

14.  The bitsy will now want to calibrate the screen.  It'll put up a
series of crosses that you should press the center of.  Hold the pen
down over each cross for a second or so; aim carefully.  Hold the
machine in your hand the way you'ld normally use it or the calibration
could be off since there is depth to the glass in the screen.

15.  You'll get a new screen with a single line at the top and a
keyboard/scribble area at the bottom.  This is a simple one file
editor.  This file is similar to plan9.ini on PC's.  There may be
garbage on the top line.  If there is, delete the garbage letters.
(Be careful here: the backspace and delete keys are adjacent on the
wee keyboard and it's much too easy to hit delete instead of
backspace, especially if you haven't calibrated the screen dead-on.)
You should be left with a single line containing (with different
numbers):
	calibrate='-16374 22919 251 -24'
You need to enter a few more things, including, but not limited to:

	user=<user-name>
	wvkey1=<key string>
	wvkey2=<key string>
	wvkey3=<key string>
	wvtxkey=<key string>
	wvessid=<wavelan name>
	auth=<ip address>
	cpu=<ip address>
	proxy=<ip address>
	fs=<ip address>

Your best bet is to copy these off a working bitsy.  wv*key* only
matter if your wireless network is encrypted.  When roaming the world,
omit wv*.  When you're done, hit the "ESC" key on the simulated
keyboard, or the side button near the word iPAQ on the bitsy.  The
system will now come up as you.  However, you'll get a message about
the flash file system being corrupted, because we haven't yet
initialized it.

16. To set up the file systems, sweep a window and give the following
sequence of commands.

	# aux/mkflashfs /dev/flash/fs
	# aux/flashfs

aux/flashfs created a Plan 9 server in /srv/brzr, which we can use to set up
default directories.

	# mount -c /srv/brzr /n/brzr
	# cd /n/brzr
	# mkdir n usr
	# mkdir n/fs n/emelie n/choline n/nslocum
	# mkdir usr/yourname usr/yourfriend

17. For safety, reboot the system:

	# reboot

18. Now reboot, go through the Linux splash screen, the Plan 9 boot
editor, and sweep yourself a new rio window.

Before you can connect to other machines, you need a way to enter
passwords and keys into factotum.  The easiest way to do this is to
run

	# auth/fgui &

in the window you just made.  The window will disappear (fgui spends
most of its time hidden), so sweep a new window and run the command

	# mfs

to connect to file servers.  You will probably need to modify mfs to
work in your environment (see point 10), though you can supply many
of the variables it needs in step 15, and doing

	# import $cpu /net

before running mfs can go a long ways.

19.  When you're all set with a working wavelan, you can download new
kernels more quickly using

	# bitsyload k

and new paqdisks using

	# bitsyload r

(r stands for ramdisk, the name of the partition into which paqdisk goes).
Note that overwriting the ramdisk partition will cause the read-only file
system which forms the root of you namespace to fail.  You'll need to
reboot immediately after bytsyload r.