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/* $NetBSD: asbootblk.c,v 1.4 1994/10/27 04:21:46 cgd Exp $ */
/*
* sys/i386/stand/asbootblk.c
*
* Boot block for Adaptech 1542 SCSI
*
* April 10, 1992
* Pace Willisson
* pace@blitz.com
*
* Placed in the public domain with NO WARRANTIES, not even the
* implied warranties for MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE.
*
* To compile:
*
* cc -O -c -DRELOC=0x70000 asbootblk.c
* ld -N -T 7c00 asbootblk.o
*
* This should result in a file with 512 bytes of text and no initialized
* data. Strip the 32 bit header and place in block 0.
*
* When run, this program copies at least the first 8 blocks of SCSI
* target 0 to the address specified by RELOC, then jumps to the
* address RELOC+1024 (skipping the boot block and disk label). Usually,
* disks have 512 bytes per block, but I don't think they ever have
* less, and it wont hurt if they are bigger, as long as RELOC + 8*SIZE
* is less than 0xa0000.
*
* This bootblock does not support fdisk partitions, and can only be used
* as the master boot block.
*/
#include <sys/param.h>
#include <sys/disklabel.h>
#include <dev/isa/ahareg.h>
/* RELOC should be defined with a -D flag to cc */
#define SECOND_LEVEL_BOOT_START (RELOC + 0x400)
#define READ_SIZE 8192
#define as_port 0x330
#define target 0
#define NBLOCKS (READ_SIZE / 512) /* how many logical blocks to read */
/* These are the parameters to pass to the second level boot */
#define dev 4 /* major device number of as driver in
i386/stand/conf.c and i386/i386/conf.c */
#define unit 0 /* partition number of root file system */
#define off 0 /* block offset of root file system */
/* inline i/o borrowed from Roell X server */
static __inline__ void
outb(port, val)
short port;
char val;
{
__asm__ volatile("outb %%al, %1" : :"a" (val), "d" (port));
}
static __inline__ unsigned int
inb(port)
short port;
{
unsigned int ret;
__asm__ volatile("xorl %%eax, %%eax; inb %1, %%al"
: "=a" (ret) : "d" (port));
return ret;
}
/* this code is linked at 0x7c00 and is loaded there by the BIOS */
asm ("
/* we're running in 16 real mode, so normal assembly doesn't work */
bootbase:
/* interrupts off */
cli
/* load gdt */
.byte 0x2e,0x0f,0x01,0x16 /* lgdt %cs:$imm */
.word _gdtarg + 2
/* turn on protected mode */
smsw %ax
orb $1,%al
lmsw %ax
/* flush prefetch queue and reload %cs */
.byte 0xea /* ljmp $8, flush */
.word flush
.word 8
flush:
/* now running in 32 bit mode */
movl $0x10,%eax
movl %ax,%ds
movl %ax,%es
movl %ax,%ss
movl $0x7c00,%esp
call _main
"); /* end of asm */
const char gdt[] = {
0, 0, 0, 0, 0, 0, 0, 0,
0xff, 0xff, 0, 0, 0, 0x9f, 0xcf, 0, /* code segment */
0xff, 0xff, 0, 0, 0, 0x93, 0xcf, 0, /* data segment */
};
const struct {
short filler;
short size;
const char *gdt;
} gdtarg = { 0, sizeof gdt - 1, gdt };
#define CRTBASE ((char *)0xb8000)
#define CHECKPOINT(x) (CRTBASE[0] = x)
volatile struct mailbox_entry mailbox[2];
const char ccb[] = {
0, /* opcode: normal read/write */
(target << 5) | 8, /* target num and read flag */
10, /* scsi cmd len */
1, /* no automatic request for sense */
READ_SIZE >> 16, /* data length */
READ_SIZE >> 8,
READ_SIZE,
RELOC >> 16, /* data pointer */
RELOC >> 8,
RELOC,
0, 0, 0, /* link pointer */
0, /* link id */
0, /* host status */
0, /* target status */
0, 0, /* reserved */
/* scsi cdb */
0x28, /* read opcode */
0, /* logical unit number */
0, 0, 0, 0, /* logical block address */
0, /* reserved */
0, NBLOCKS, /* transfer length */
0, /* link control */
};
int (*f)();
main ()
{
int i;
extern char edata[], end[];
char volatile * volatile p, *q;
int physaddr;
CHECKPOINT ('a');
/* clear bss */
for (p = edata; p < end; p++)
*p = 0;
f = (int (*)())SECOND_LEVEL_BOOT_START;
/* dma setup: see page 5-31 in the Adaptech manual */
/* this knows we are using drq 5 */
outb (0xd6, 0xc1);
outb (0xd4, 0x01);
outb (as_port + AS_CONTROL, AS_CONTROL_SRST);
/* delay a little */
inb (0x84);
while (inb (as_port + AS_STATUS) != (AS_STATUS_INIT | AS_STATUS_IDLE))
;
CHECKPOINT ('b');
as_put_byte (AS_CMD_MAILBOX_INIT);
as_put_byte (1); /* one mailbox out, one in */
as_put_byte ((int)mailbox >> 16);
as_put_byte ((int)mailbox >> 8);
as_put_byte ((int)mailbox);
while (inb (as_port + AS_STATUS) & AS_STATUS_INIT)
;
CHECKPOINT ('c');
mailbox[0].msb = (int)ccb >> 16;
mailbox[0].mid = (int)ccb >> 8;
mailbox[0].lsb = (int)ccb;
mailbox[0].cmd = 1;
as_put_byte (AS_CMD_START_SCSI_COMMAND);
/* wait for done */
while (mailbox[1].cmd == 0)
;
CHECKPOINT ('d');
if (mailbox[1].cmd != 1) {
/* some error */
CHECKPOINT ('X');
while (1);
}
CHECKPOINT ('e');
/* the optimazation that gcc uses when it knows we are jumpping
* to a constant address is broken, so we have to use a variable
* here
*/
(*f)(dev, unit, off);
}
int
as_put_byte (val)
int val;
{
while (inb (as_port + AS_STATUS) & AS_STATUS_CDF)
;
outb (as_port + AS_DATA_OUT, val);
}
asm ("
ebootblkcode:
. = 510
.byte 0x55
.byte 0xaa
ebootblk: /* MUST BE EXACTLY 0x200 BIG FOR SURE */
");
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