motorola_powerpc/bootloader/README.md

0001 Motorola PowerPC
0002 ================
0003
0004 The code in this directory has been taken WITH PERMISSION from
0005 Gabriel Paubert, paubert@iram.es. The main reason for having
0006 a separate bootloader for PreP compliant firmware is that the
0007 initial code is relocated by firmware at an unknow address
0008 (actually  0x5000 on motorola MCP750) and that as Gabriel I
0009 think having a relocatable bootloder code is a must.
0010
0011 So the way of building a binary executable that can be booted via
0012 hard disk or network boot goes like this :
0013
0014         - make a RTEMS executable,
0015         - put is as data section in the bootloder binary,
0016         - relink the loader (see make-exe macros for details),
0017
0018 I would like to thank Gabriel for his support and his code.
0019 The original code can be found in form of a patch to official linux
0020 kernel at (I insist not vger ppc kernel or Imac ppc kernels!!) :
0021
0022 <ftp://vlab1.iram.es/pub/linux-2.2/>
0023
0024 After applying the patch, the code is located in a new directory
0025 called prepboot.
0026
0027 (NB : note use ftp not netscape...)
0028
0029 Note that the actual code differs a lot since Gabriel choose to use
0030 a CHRP compliant mapping instead of a Prep Mapping to save
0031 BATs. I had no time to upgrade the code to its new one allthough
0032 I agree it should be done...
0033
0034 I have also splitted the original code to have a more modular
0035 design enabling to reuse code between the loader and RTEMS
0036 initialization (e.g printk, ...).
0037
0038 Eric Valette (valette@crf.canon.fr)
0039
0040
0041 2003/5/7, Greg Menke, gregory.menke@gsfc.nasa.gov
0042
0043 Reworked the pci bus 0 initialization a little and added support for
0044 configuring an arbitrary number of other busses & their respective
0045 bridges.  Also added support for configuring IO ranges below 0x10000,
0046 which I think is reasonable given this is a PowerPC bsp.