Re: Netboot on Vax

[Martin Husemann <martin%duskware.de@localhost>]

I don't understand why /usr/mdec/boot should not work if loaded at 0
and started there.

Certainly the old version I have installed on my mop server (and which I used
to boot a vaxstation) starts just the same as the -current one.

However, it starts by relocating itself:

ALTENTRY(start)
        nop;nop;
        movl    $_C_LABEL(start), %sp   # Probably safe place for stack
        pushr   $0x1fff         # save for later usage

        subl3   $_C_LABEL(start), $_C_LABEL(edata), %r0
        movab   _C_LABEL(start), %r1 # get where we are
        movl    $_C_LABEL(start), %r3 # get where we want to be
        cmpl    %r1,%r3         # are we where we want to be?
        beql    relocated       # already relocated, skip copy
        movc3   %r0,(%r1),(%r3) # copy
        subl3   $_C_LABEL(edata), $_C_LABEL(end), %r2
        movc5   $0,(%r3),$0,%r2,(%r3) # Zero bss

        movpsl  -(%sp)
        pushl   $relocated
        rei
relocated:                      # now relocation is done !!!
        movl    %sp,_C_LABEL(bootregs)  # *bootregs
        calls   $0, _C_LABEL(Xmain)     # Were here!
        halt                    # no return

I think I did not touch this part while reworking stuff for the 780 and CDs.

Martin