[9fans] executable file format, bootable (sparc)

[9fans] executable file format, bootable (sparc)

[forsyth]

it is ages since i booted a sparc with plan9, but i believe
the sparc plan 9 boot format is a sun a.out format that sun's
sparc tftpboot rom (of the time) was willing to load.
it probably does strip the header.
only the debuggers (both programs and humans), size, nm, etc
use the symbols and pc/line number map.
neither kernel nor applications need them (including ps).

[9fans] executable file format, bootable (sparc)

[Bengt]

greetings,

for reasons that can be explained (email me) i would like to know how a
memory image should look, given the parts found in the bootable binary
file called 9ss (or 9ss10).

from the manual page about a.out.h, section 6, i have understood that the
normal executable file format is 6 parts:
1 header
2 text
3 data
4 symbols
5 68020 specific
6 pc->line number table

and that the memory image looks like:
1 text (header and text)
2 data
3 stack (bss?)

since i am only interested in the bootable executable (kernel) have have looked
into the source and found that the text segment of the memory image in
this case only contains text, no header.



is the abovementioned correct?

if so, would it be possible to modify a boot-loader from some other
operating system (openbsd) that took the plan9 kernel file, created the
memory image as described above and started to execute this image?

what i am worried about is the lack of symbols and pc->line number table
in this image. since the kernel file would not be present in the plan9
filesystem it seems to me that this information would be lost.


Best Wishes, Bengt
===============================================================
Everything aforementioned should be regarded as totally private
opinions, and nothing else. bengt@softwell.se
``His great strength is that he is uncompromising. It would make
him physically ill to think of programming in C++.''