freebsd-dev/sys/boot/i386/loader/main.c
Mike Smith af1f6e0673 Implement a simple LRU block cache. By default this is initialised to 16k,
and will bypass transfers for more than 8k.  Blocks are invalidated after
2 seconds, so removable media should not confuse the cache.

The 8k threshold is a compromise; all UFS transfers performed by
libstand are 8k or less, so large file reads thrash the cache.
However many filesystem metadata operations are also performed using
8k blocks, so using a lower threshold gives poor performance.

Those of you with an eye for cache algorithms are welcome to tell me
how badly this one sucks; you can start with the 'bcachestats' command
which will print the contents of the cache and access statistics.
1998-11-02 23:28:11 +00:00

234 lines
6.9 KiB
C

/*-
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: main.c,v 1.13 1998/10/22 20:23:58 msmith Exp $
*/
/*
* MD bootstrap main() and assorted miscellaneous
* commands.
*/
#include <stand.h>
#include <string.h>
#include <machine/bootinfo.h>
#include <sys/reboot.h>
#include "bootstrap.h"
#include "libi386/libi386.h"
#include "btxv86.h"
/* Arguments passed in from the boot1/boot2 loader */
static struct
{
u_int32_t howto;
u_int32_t bootdev;
u_int32_t res0;
u_int32_t res1;
u_int32_t res2;
u_int32_t bootinfo;
} *kargs;
static u_int32_t initial_howto;
static u_int32_t initial_bootdev;
static struct bootinfo *initial_bootinfo;
struct arch_switch archsw; /* MI/MD interface boundary */
static void extract_currdev(void);
static int isa_inb(int port);
static void isa_outb(int port, int value);
/* from vers.c */
extern char bootprog_name[], bootprog_rev[], bootprog_date[], bootprog_maker[];
/* XXX debugging */
extern char end[];
void
main(void)
{
int i;
/* Pick up arguments */
kargs = (void *)__args;
initial_howto = kargs->howto;
initial_bootdev = kargs->bootdev;
initial_bootinfo = (struct bootinfo *)PTOV(kargs->bootinfo);
/*
* Initialise the heap as early as possible. Once this is done, malloc() is usable.
*
* XXX better to locate end of memory and use that
*/
setheap((void *)end, (void *)(end + (384 * 1024)));
/*
* XXX Chicken-and-egg problem; we want to have console output early, but some
* console attributes may depend on reading from eg. the boot device, which we
* can't do yet.
*
* We can use printf() etc. once this is done.
* If the previous boot stage has requested a serial console, prefer that.
*/
if (initial_howto & RB_SERIAL)
setenv("console", "comconsole", 1);
cons_probe();
/*
* Initialise the block cache
*/
bcache_init(32, 512); /* 16k cache XXX tune this */
/*
* March through the device switch probing for things.
*/
for (i = 0; devsw[i] != NULL; i++)
if (devsw[i]->dv_init != NULL)
(devsw[i]->dv_init)();
printf("\n");
printf("%s, Revision %s %d/%dkB\n", bootprog_name, bootprog_rev, getbasemem(), getextmem());
printf("(%s, %s)\n", bootprog_maker, bootprog_date);
extract_currdev(); /* set $currdev and $loaddev */
setenv("LINES", "24", 1); /* optional */
archsw.arch_autoload = i386_autoload;
archsw.arch_getdev = i386_getdev;
archsw.arch_copyin = i386_copyin;
archsw.arch_copyout = i386_copyout;
archsw.arch_readin = i386_readin;
archsw.arch_isainb = isa_inb;
archsw.arch_isaoutb = isa_outb;
interact(); /* doesn't return */
}
/*
* Set the 'current device' by (if possible) recovering the boot device as
* supplied by the initial bootstrap.
*
* XXX should be extended for netbooting.
*/
static void
extract_currdev(void)
{
struct i386_devdesc currdev;
int major, biosdev;
/* We're booting from a BIOS disk, try to spiff this */
currdev.d_dev = devsw[0]; /* XXX presumes that biosdisk is first in devsw */
currdev.d_type = currdev.d_dev->dv_type;
if ((initial_bootdev & B_MAGICMASK) != B_DEVMAGIC) {
/* The passed-in boot device is bad */
currdev.d_kind.biosdisk.slice = -1;
currdev.d_kind.biosdisk.partition = 0;
biosdev = -1;
} else {
currdev.d_kind.biosdisk.slice = (B_ADAPTOR(initial_bootdev) << 4) + B_CONTROLLER(initial_bootdev) - 1;
currdev.d_kind.biosdisk.partition = B_PARTITION(initial_bootdev);
biosdev = initial_bootinfo->bi_bios_dev;
major = B_TYPE(initial_bootdev);
/*
* If we are booted by an old bootstrap, we have to guess at the BIOS
* unit number. We will loose if there is more than one disk type
* and we are not booting from the lowest-numbered disk type
* (ie. SCSI when IDE also exists).
*/
if ((biosdev == 0) && (B_TYPE(initial_bootdev) != 2)) /* biosdev doesn't match major */
biosdev = 0x80 + B_UNIT(initial_bootdev); /* assume harddisk */
}
if ((currdev.d_kind.biosdisk.unit = bd_bios2unit(biosdev)) == -1) {
printf("Can't work out which disk we are booting from.\n"
"Guessed BIOS device 0x%x not found by probes, defaulting to disk0:\n", biosdev);
currdev.d_kind.biosdisk.unit = 0;
}
env_setenv("currdev", EV_VOLATILE, i386_fmtdev(&currdev), i386_setcurrdev, env_nounset);
env_setenv("loaddev", EV_VOLATILE, i386_fmtdev(&currdev), env_noset, env_nounset);
}
COMMAND_SET(reboot, "reboot", "reboot the system", command_reboot);
static int
command_reboot(int argc, char *argv[])
{
printf("Rebooting...\n");
delay(1000000);
__exit(0);
}
/* provide this for panic, as it's not in the startup code */
void
exit(int code)
{
__exit(code);
}
COMMAND_SET(heap, "heap", "show heap usage", command_heap);
static int
command_heap(int argc, char *argv[])
{
mallocstats();
printf("heap base at %p, top at %p\n", end, sbrk(0));
return(CMD_OK);
}
/* ISA bus access functions for PnP, derived from <machine/cpufunc.h> */
static int
isa_inb(int port)
{
u_char data;
if (__builtin_constant_p(port) &&
(((port) & 0xffff) < 0x100) &&
((port) < 0x10000)) {
__asm __volatile("inb %1,%0" : "=a" (data) : "id" ((u_short)(port)));
} else {
__asm __volatile("inb %%dx,%0" : "=a" (data) : "d" (port));
}
return(data);
}
static void
isa_outb(int port, int value)
{
u_char al = value;
if (__builtin_constant_p(port) &&
(((port) & 0xffff) < 0x100) &&
((port) < 0x10000)) {
__asm __volatile("outb %0,%1" : : "a" (al), "id" ((u_short)(port)));
} else {
__asm __volatile("outb %0,%%dx" : : "a" (al), "d" (port));
}
}