From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <33aa3b4ddd8d675fa801e5870918d68d@plan9.bell-labs.com>
From: "Russ Cox" <rsc@plan9.bell-labs.com>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] kernel config changes
In-Reply-To: <C2ACD5D6-2F45-11D7-8ECC-000A27AE643E@sockfarm.net>
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Date: Fri, 24 Jan 2003 11:52:40 -0500
Topicbox-Message-UUID: 46865c76-eacb-11e9-9e20-41e7f4b1d025

There's now both port/initcode.c, which does almost
what I posted (I've since noticed that the exec cmd line
args get passed into the main function, now called startboot):

#include <u.h>
#include <libc.h>

char cons[] = "#c/cons";
char boot[] = "/boot/boot";
char dev[] = "/dev";
char c[] = "#c";
char e[] = "#e";
char ec[] = "#ec";
char s[] = "#s";
char srv[] = "/srv";
char env[] = "/env";

void
startboot(char *argv0, char **argv)
{
	open(cons, OREAD);
	open(cons, OWRITE);
	open(cons, OWRITE);
	bind(c, dev, MAFTER);
	bind(ec, env, MAFTER);
	bind(e, env, MCREATE|MAFTER);
	bind(s, srv, MREPL|MCREATE);
	exec(boot, argv);
	for(;;);
}

On the MIPS there is still an assembly stub
that initializes R30 (SB).

TEXT	_main(SB), $8
	MOVW	$setR30(SB), R30
	MOVW	$boot(SB), R1
	ADD	$12, R29, R2	/* get a pointer to 0(FP) */
	MOVW	R1, 4(R29)
	MOVW	R2, 8(R29)
	JAL	startboot(SB)

The 386 uses just the C code -- no assembly required.

You should be able to do almost exactly the same
thing for the bitsy -- SB is R12.

Russ