Booting off the CDROM and starting the installation
When issuing the boot cdrom command from the boot promt the system loads its specific bootblock and gets redirected to slice 1 to start loading the kernel. The system comes up into Single User Mode.
Since there is only a minimal /usr on slice 1, the OS mounts a full /usr from slice 0 over the previous minimal /usr.
This can be found in /cdrom/cdrom1/s0/Solaris_2.6/Tools/Boot/usr
The system comes up and starts the shell script /sbin/suninstal. Suninstall does:
Mount the path to the JumpStart directory (profind)
Validate the contents of the JumpStart directory (chkprobe)
Set the application type (jumpstart or interactive)
JumpStart (Custom or Factory) begin script
Save the JumpStart environment variables
Mount the path to the SolStart directory
Validate the contents of the SolStart directory (chkprobe)
SolStart (SunSoft and OEM) begin script
Save the SolStart environment variables
Restore the JumpStart environment variables
Interactive install (installtool/ttinstall)
or
JumpStart (Custom or Factory) profile install (pfinstall/pfupgrade)
Restore the SolStart environment variables
SolStart (SunSoft and OEM) finish script
Restore the JumpStart environment variables
JumpStart (Custom or Factory) finish script
Cleanup
As I understand, there is no difference in doing a JumpStart installation over the net or doing the installation from CD.
Altering the CDROM
So far you might ask yourself, what are the difficulties in burning a custom CD.
The problem lies in the VTOC! When booting off CDROM, the boot prom checks the VTOC. This is the \'Table of Contents\' which is located in the first cylinder (512 Bytes) of slice 0. The partition map of the CDROM is specified in the VTOC together with a checksum. Whenever changing the partition layout, the Sun system WILL NOT BOOT OFF THIS CDROM ANYMORE. So far I do not know of any tool to create a new VTOC. Hints for this are very welcome.
A second problem is the ufs format. Slice 1 to 5 MUST be in ufs format. The ufs format is bound to the disk geometry which is different on CD and your harddrive.
The VTOC
At first we look at the layout of the CDROM. Remember: To print the VTOC, vold MUST NOT be running and the CDROM MUST be unmounted!
# prtvtoc /dev/dsk/c0t6d0s2
* /dev/dsk/c0t6d0s2 partition map
*
* Dimensions:
* 512 bytes/sector
* 640 sectors/track
* 1 tracks/cylinder
* 640 sectors/cylinder
* 2048 cylinders
* 2048 accessible cylinders
*
* Flags:
* 1: unmountable
* 10: read-only
*
* Unallocated space:
* First Sector Last
* Sector Count Sector
* 1088000 3200 1091199
* 1100800 209920 1310719
*
* First Sector Last
* Partition Tag Flags Sector Count Sector Mount Directory 0 4 10 0 984960 984959
1 2 10 984960 103040 1087999
2 0 00 1088000 3200 1091199
3 0 00 1091200 3200 1094399
4 0 00 1094400 3200 1097599
5 0 00 1097600 3200 1100799
#
The size of the partitions can be calculated by multiplying the Count field by 512 eg:
Slice 0: 984960 sectors * 512 bytes / sector = 504299520 Bytes = 481 MB
WE ARE ABSOLUTELY BOUND TO THIS PARTITION MAP! The 110MB of unallocated space CANNOT be used.
Whatever we change, WE MUST STAY IN THE VTOC SPECIFIED RANGE
A second, more elaborate procedure
Since the available size is limited to about 300 Megs, I have thought about other possibilities. Further I would like to install the OS off the virgin files provided on the CD. I do not want to use an image. Since I want no human interaction, the Sun HW should have two CDROM players. This costs additional 200$ but we have max convenience. Note: It could also be done with somebody changing CD\'s inbetween the installation process.
The main problem is changing the /sbin/suninstall file on the CDROM to accomodate my changes. This file lies on slice 1 of the CD. The changes are that severe that they cannot be made using a binary editor and changing a few lines in this file. I am still working on getting the whole procedure to run as I want to. Therefore the noted changes are ideas and NOT tested out yet!!!
change suninstall to load a config file off diskette, use this as config for pfinstall to install the machine.
reboot the machine
start application installation off second CDROM
reboot and finish up
The problem lies in changing the suninstall file. Here is what I did (Analog to the document from Victoria Lau):
Create a partition of about 100MB.
Create a second partition of about 700 MB, newfs this partition and mount it.
follow steps 1 - 3 of 3.2.1
We well need all the slices, so we might as well do the for statements from 0 to 5
The image of the CDROM slices should now reside on the new partition.
dd if=cdrom.s1 of=/dev/rdsk/c0t1d0s5 bs=8k
c0t1d0s5 is the raw device of the 100Mb Partition we created before.
Remember the number of blocks which dd reports
fsck /dev/rdsk/c0t1d0s5
mount /dev/dsk/c0t1d0s5 /mnt/instcdrom
cd /mnt/instcdrom; df -k shows how much space we have left.
change the files to use our custom installation procedure
sync;sync;sync; umount /mnt/instcdrom
mv cdrom.s1 cdrom.s1.orig
dd if=/dev/rdsk/c0t1d0s5 of=cdrom.s1 count=5240
5240 is the number of blocks which dd reported in step 4
cat all the images in one file which you are able to burn. If you did not change anything in slice 0, the VTOC and PAD File are not needed.
cat cdrom.s0 > cd_image
cat cdrom.s1 >> cd_image
..
cat cdrom.s5 >> cd_image
Burn this image to the CDROM drive using cdrecord, HyCD, Gear. etc
eg. cdrecord speed=4 dev=0,3,0 cd_image
As a starting point a tar file is created from slice 0, 1 and 2. The
bootblocks from slice 2 and
upwards are also extracted.
We partition the harddisk to contain all the slices except one, which
spans all used partitions.
Sizes of partitions are adapted to use all available space on the new
cd-rom(74 minutes).
The partitions are filled again with the original data and adapted to
out needs (slice 0 will change
from HSFS into UFS).
The bootblocks are put into place on the corresponding raw partition.
We now use \"dd\" to make a copy of the disk in a file, skipping the VTOC.
The VTOC is generated with a separate command and prepended to the
existing file.
This gives you the opportunity to leave out now used slices in the VTOC
or remap the existing
ones (Solaris 2.6 format seems to need slice 2 for disk information).
The next items are relevant:
- the tar command from Sun is capable to store and retreive all types of
file (also names pipes).
This has been verified for Solaris 2.5.1 and 2.6.
- the depth of the driectory tree on slice 0 is critical, one must not
use the dot (.) as starting point,
but a list of files inside it . This limitation has been built into
tar to detect endless loops.
- the files in slices 2 and upwards are identical (only a redirect file)
- the standard cd-rom boot/installation contains a fallback mount
attempt for slice 0, trying
to mount it as a UFS filesystem is the hsfs mount fails.
- all partitions must have a size of a multiple of 4 blocks of 512 bytes
(caused by the 2048 byte
blocks a cd-drive uses)
- the disk used has some influence on the partitions sizes, depending on
its cylinder size.
Any package which can write a cd-rom image to cd-r can be used to write
the data file.
The advantage of this approach is the increased size of slice 0, which
can be used to add your
own data (we also replace suninstall to start our own installation).
I hope this information is usefull,
Kittykatty27
