On Mon, 2001-11-05 at 17:44, Richard Hodges wrote:
> On 5 Nov 2001, Pete Popov wrote:
> > On Mon, 2001-11-05 at 17:09, Richard Hodges wrote:
> > > Would anyone be able to provide information on the arguments
> > > to kernel_entry (in head.S)?
> > >
> > > The first two look pretty straightforward, argument count and
> > > string vectors. I assume that argument zero is actually the
> > > first argument, and not "vmlinux"?
> > >
> > > What are the third (ulong) and fourth (int *) arguments? I have
> > > read head.S and searched for days trying to find this info :-(
> > >
> > > I thought PMON would be a decent reference, but run_target() only
> > > seems to set $4 and $5, before calling _go().
> > That's boot code specific. MIPS Tech's yamon passes:
> > 0: number of arguments
> > 1: pointer to first arg
> > 2: pointer to environment variables
> > 3: pointer to prom routines you can call
> Okay, I think I have it now. It looks like _only_ prom_init() is
> interested in these arguments.
> 1. kernel_entry() gives them to init_arch(),
> 2. init_arch gives them to prom_init(),
> 3. prom_init() does whatever it wants (eg, builds arcs_cmdline)
> 4. init_arch ends with a call to start_kernel(), and the original
> arguments are effectively thrown away.
> Or put more simply, the kernel_entry arguments are only used by
> prom_init(). Is this right?
I believe that's correct. arch/mips/kernel/setup.c saves arcs_cmdline in
command_line and that's the end of arcs_cmdline.