| 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. |