3.3.3.1. The old scheme: hidden partition

Here is the output of fdisk which represents the hard drive of a box with 16MB PALO space, 128MB swap space and about 1GB '/' partition:

bash# fdisk -l /dev/sda

Disk /dev/sda: 133 heads, 62 sectors, 1017 cylinders
Units = cylinders of 8246 * 512 bytes

	 Device Boot    Start       End    Blocks   Id  System
/dev/sda1   *         1         4     16461   f0  Linux/PA-RISC boot
/dev/sda2             5        34    123690   82  Linux swap
/dev/sda3            35       277   1001889   83  Linux
					

Now let's deal with PALO configuration. Here are the various parameters you can change:

• recoverykernel is (as the name suggests) the path to the kernel you want to boot within a failsafe session, it will be stored in the 'f0-type' partition.

• bootloader is the path to the iplboot boot loader utility which is created by PALO when you issue a make iplboot.

  Usually you don't want to change or even specify this.

• init-partitioned is used to indicate the pre-partionned device where palo will write its boot parameters. The effect is immediate. It means that PALO is going to write on (and erase the content of) the 'f0' partition of this device, which has to exist.

• commandline: the first digit is the number of your ext2/ext3 partition where the kernel file is located, as reported by fdisk. Logically, the next string is the absolute path to the kernel from the root of THIS partition [1]. The following space separated parameters (do NOT use any quotation mark!) will be passed to the kernel as its arguments. e.g.: HOME= and TERM= are environmental parameters passed to init when booting. They are not compulsory but they can be useful. root= tells the kernel which partition it must mount as the root file system while booting. It can be tricky when you have more than one disk, and is a mandatory argument. Maximum length for the commandline is 127 characters.

  You can also add console=, to force the designation of the output console. You should remember that console=ttyS0 is for a serial console and console=tty0 is for a STI (graphic) console. Support for the MUX console (if enabled in the kernel, see Section 5.2) has been added, using console=ttyB0. Recent versions of PALO auto detect the right console path (except for MUX), and can figure out whether a 32bit or 64bit kernel should be used. If not, please mail to the mailing list. Last but not least, if you are using Debian 2.6 kernels, you will also need to add initrd=X/path/to/initrd, following the same rules as for the kernel path[1], see above.

According the above fdisk example, we want to use /dev/sda3 as our root partition. Thus, the configuration file should look like that:

# The following arguments are set up for booting from /dev/sda, specifically
# mounting partition 3 as root, and using /boot/vmlinux as both the
# recovery kernel, and the default dynamically-booted kernel.
--recoverykernel=/boot/vmlinux
--init-partitioned=/dev/sda
--commandline=3/boot/vmlinux root=/dev/sda3
						

3.3.3.2. The new scheme: mounted partition

Looking at the previous example (Section 3.3.3.1), very little things need to be changed. Essentially, if you had the need for a separate /boot partition, it will be gone in the scheme detailed below. The configuration for PALO will be a little bit different as well, but that's about it.

Here is the output of fdisk which represents the hard drive of a box with 100MB PALO space (which will be mounted as /boot), 128MB swap space and about 1GB '/' partition (bear in mind that the f0 partition must still be wholy contained within the first 2GB of the disk):

bash# fdisk -l /dev/sda

Disk /dev/sda: 133 heads, 62 sectors, 1017 cylinders
Units = cylinders of 8246 * 512 bytes

	 Device Boot    Start       End    Blocks   Id  System
/dev/sda1   *         1        26    100461   f0  Linux/PA-RISC boot
/dev/sda2            27        36    123690   82  Linux swap
/dev/sda3            37       277    917889   83  Linux
					

Now let's deal with PALO configuration. Contrary to the previous example, there are far less options to put in the configuration file, and the setup is a single step operation: the initialization step, which needs only to be done once.

To initialize for the first time the PALO partition as something the Linux system can understand (ext2 or ext3 filesystem), you need to run the following command (as root):

[user@machine ~/dir]> palo --format-as=N --init-partitioned=target_disk
					

Where N is either 2 for ext2 or 3 for ext3, and target_disk is the device which contains the PALO partition, /dev/sda in the current example. Continuing with this example, assuming we want an ext3 partition we would use:

[user@machine ~/dir]> palo --format-as=3 --init-partitioned=/dev/sda
					

Do NOT use mkfs or mke2fs to generate the filesystem on this partition. PALO marks blocks as used where the boot loader portion of PALO is stored on disk. These tools don't know about PALO boot loader!

This needs to be run only once for it will erase any existing data on the f0 partition.

Finally, we need to tell PALO about the partition, how we want it to be used, and how we don't want it to be erased everytime PALO is being run. Thus, keeping in sync with our current example, the configuration file should look like that:

# The following arguments are set up for booting from /dev/sda, specifically
# mounting partition 3 as root and booting the vmlinux file in /dev/sda1, palo
# partition formatted as ext3.
--update-partitioned=/dev/sda --format-as=3
--commandline=1/vmlinux root=/dev/sda3
						

As one can see, since we will be storing our kernels directly on the f0 partition, we tell PALO to load them from it (hence the 1 in the commandline argument.

In the previous section (Section 3.3.3.1) we dealt with the init-partitioned parameter. Here, we use update-partitioned instead, which, contrary to the former, tells PALO to not erase the content of the partition when run[2].