[Etherboot-developers] NetBSD ELF/a.out support

[Wojciech P. <wo...@te...>]

anyone working on it?

how can i help?

all i found is that kernel should be loaded beginning from
LMA(VMA)-c0000000 (which is 1MB in all kernels i looked at from version
1.3.3 to 1.6)

Idx Name          Size      VMA       LMA       File off  Algn
  0 .text         0014df54  c0100000  c0100000  00001000  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  1 .rodata       000287a1  c024df60  c024df60  0014ef60  2**5
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  2 .data         0001acf0  c0277720  c0277720  00177720  2**5
                  CONTENTS, ALLOC, LOAD, DATA
  3 .bss          0003e1fc  c0292420  c0292420  00192420  2**5


kernel should be started in flat mode with paging off, given parameters on
stack with C standard:

(howto, [bootdev], bootinfo, esym, basemem, extmem)

howto is (2 if single user)|(1 if ask for boot device)|(4 if start
debugger)

it could be always 0 for etherboot

bootdev should be 0 for new kernels - not used.

esym is used for debugger if kernel symbols are loaded to memory. it's
probably offset from kernel code to beginning of symbols, 0 if no symbols.

bootinfo is a pointer to bootinfo structure. first 4 bytes says how many
elements it has, then there are elements (like boot console info, bios
disk geometry etc.) - all well defined in NetBSD's bootinfo.h


how can i help to support it (my assembly isn't best right now)?

tried using FreeBSD support in etherboot - kernel is loaded fine then
hangs.


NetBSD already has ROM files but for only few cards and needs 32K ROMs,
and
pxeboot.bin that works for any PXE capable cards.

anyway having this in etherboot will give user a flexibility to run any OS
without reprogramming EPROM