+/*
+ * 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 "param.h"
+#include "disklabel.h"
+#include "i386/isa/asreg.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[] = {
+ 3, /* 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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