| Information about the Linux/PPC kernel images | |
| ===================================================================== | |
| Please mail me (Cort Dougan, cort@fsmlabs.com) if you have questions, | |
| comments or corrections. | |
| This document is meant to answer several questions I've had about how | |
| the PReP system boots and how Linux/PPC interacts with that mechanism. | |
| It would be nice if we could have information on how other architectures | |
| boot here as well. If you have anything to contribute, please | |
| let me know. | |
| 1. PReP boot file | |
| This is the file necessary to boot PReP systems from floppy or | |
| hard drive. The firmware reads the PReP partition table entry | |
| and will load the image accordingly. | |
| To boot the zImage, copy it onto a floppy with dd if=zImage of=/dev/fd0h1440 | |
| or onto a PReP hard drive partition with dd if=zImage of=/dev/sda4 | |
| assuming you've created a PReP partition (type 0x41) with fdisk on | |
| /dev/sda4. | |
| The layout of the image format is: | |
| 0x0 +------------+ | |
| | | PReP partition table entry | |
| | | | |
| 0x400 +------------+ | |
| | | Bootstrap program code + data | |
| | | | |
| | | | |
| +------------+ | |
| | | compressed kernel, elf header removed | |
| +------------+ | |
| | | initrd (if loaded) | |
| +------------+ | |
| | | Elf section table for bootstrap program | |
| +------------+ | |
| 2. MBX boot file | |
| The MBX boards can load an elf image, and relocate it to the | |
| proper location in memory - it copies the image to the location it was | |
| linked at. |