1          Information about the Linux/PPC kernel images
2=====================================================================
3
4Please mail me (Cort Dougan, cort@fsmlabs.com) if you have questions,
5comments or corrections.
6
7This document is meant to answer several questions I've had about how
8the PReP system boots and how Linux/PPC interacts with that mechanism.
9It would be nice if we could have information on how other architectures
10boot here as well.  If you have anything to contribute, please
11let me know.
12
13
141. PReP boot file
15
16  This is the file necessary to boot PReP systems from floppy or
17  hard drive.  The firmware reads the PReP partition table entry
18  and will load the image accordingly.
19
20  To boot the zImage, copy it onto a floppy with dd if=zImage of=/dev/fd0h1440
21  or onto a PReP hard drive partition with dd if=zImage of=/dev/sda4
22  assuming you've created a PReP partition (type 0x41) with fdisk on
23  /dev/sda4.
24
25  The layout of the image format is:
26
27  0x0     +------------+
28          |            | PReP partition table entry
29          |            |
30  0x400   +------------+
31          |            | Bootstrap program code + data
32          |            |
33          |            |
34          +------------+
35          |            | compressed kernel, elf header removed
36          +------------+
37          |            | initrd (if loaded)
38          +------------+
39          |            | Elf section table for bootstrap program
40          +------------+
41
42
432. MBX boot file
44
45  The MBX boards can load an elf image, and relocate it to the
46  proper location in memory - it copies the image to the location it was
47  linked at.
48