237 lines
5.0 KiB
C
237 lines
5.0 KiB
C
/*
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* sys/i386/stand/asbootblk.c
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*
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* Boot block for Adaptech 1542 SCSI
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*
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* April 10, 1992
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* Pace Willisson
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* pace@blitz.com
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*
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* Placed in the public domain with NO WARRANTIES, not even the
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* implied warranties for MERCHANTABILITY or FITNESS FOR A
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* PARTICULAR PURPOSE.
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*
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* To compile:
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*
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* cc -O -c -DRELOC=0x70000 asbootblk.c
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* ld -N -T 7c00 asbootblk.o
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*
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* This should result in a file with 512 bytes of text and no initialized
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* data. Strip the 32 bit header and place in block 0.
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*
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* When run, this program copies at least the first 8 blocks of SCSI
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* target 0 to the address specified by RELOC, then jumps to the
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* address RELOC+1024 (skipping the boot block and disk label). Usually,
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* disks have 512 bytes per block, but I don't think they ever have
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* less, and it wont hurt if they are bigger, as long as RELOC + 8*SIZE
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* is less than 0xa0000.
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*
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* This bootblock does not support fdisk partitions, and can only be used
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* as the master boot block.
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*
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* $Id: asbootblk.c,v 1.3 1993/05/22 08:02:07 cgd Exp $
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*/
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#include "param.h"
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#include "disklabel.h"
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#include "i386/isa/asreg.h"
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/* RELOC should be defined with a -D flag to cc */
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#define SECOND_LEVEL_BOOT_START (RELOC + 0x400)
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#define READ_SIZE 8192
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#define as_port 0x330
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#define target 0
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#define NBLOCKS (READ_SIZE / 512) /* how many logical blocks to read */
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/* These are the parameters to pass to the second level boot */
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#define dev 4 /* major device number of as driver in
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i386/stand/conf.c and i386/i386/conf.c */
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#define unit 0 /* partition number of root file system */
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#define off 0 /* block offset of root file system */
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/* inline i/o borrowed from Roell X server */
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static __inline__ void
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outb(port, val)
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short port;
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char val;
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{
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__asm__ volatile("outb %%al, %1" : :"a" (val), "d" (port));
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}
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static __inline__ unsigned int
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inb(port)
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short port;
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{
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unsigned int ret;
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__asm__ volatile("xorl %%eax, %%eax; inb %1, %%al"
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: "=a" (ret) : "d" (port));
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return ret;
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}
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/* this code is linked at 0x7c00 and is loaded there by the BIOS */
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asm ("
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/* we're running in 16 real mode, so normal assembly doesn't work */
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bootbase:
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/* interrupts off */
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cli
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/* load gdt */
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.byte 0x2e,0x0f,0x01,0x16 /* lgdt %cs:$imm */
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.word _gdtarg + 2
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/* turn on protected mode */
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smsw %ax
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orb $1,%al
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lmsw %ax
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/* flush prefetch queue and reload %cs */
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.byte 0xea /* ljmp $8, flush */
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.word flush
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.word 8
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flush:
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/* now running in 32 bit mode */
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movl $0x10,%eax
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movl %ax,%ds
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movl %ax,%es
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movl %ax,%ss
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movl $0x7c00,%esp
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call _main
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"); /* end of asm */
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const char gdt[] = {
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0, 0, 0, 0, 0, 0, 0, 0,
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0xff, 0xff, 0, 0, 0, 0x9f, 0xcf, 0, /* code segment */
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0xff, 0xff, 0, 0, 0, 0x93, 0xcf, 0, /* data segment */
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};
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const struct {
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short filler;
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short size;
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const char *gdt;
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} gdtarg = { 0, sizeof gdt - 1, gdt };
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#define CRTBASE ((char *)0xb8000)
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#define CHECKPOINT(x) (CRTBASE[0] = x)
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volatile struct mailbox_entry mailbox[2];
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const char ccb[] = {
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0, /* opcode: normal read/write */
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(target << 5) | 8, /* target num and read flag */
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10, /* scsi cmd len */
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1, /* no automatic request for sense */
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READ_SIZE >> 16, /* data length */
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READ_SIZE >> 8,
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READ_SIZE,
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RELOC >> 16, /* data pointer */
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RELOC >> 8,
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RELOC,
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0, 0, 0, /* link pointer */
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0, /* link id */
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0, /* host status */
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0, /* target status */
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0, 0, /* reserved */
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/* scsi cdb */
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0x28, /* read opcode */
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0, /* logical unit number */
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0, 0, 0, 0, /* logical block address */
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0, /* reserved */
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0, NBLOCKS, /* transfer length */
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0, /* link control */
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};
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int (*f)();
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main ()
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{
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int i;
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extern char edata[], end[];
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char volatile * volatile p, *q;
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int physaddr;
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CHECKPOINT ('a');
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/* clear bss */
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for (p = edata; p < end; p++)
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*p = 0;
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f = (int (*)())SECOND_LEVEL_BOOT_START;
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/* dma setup: see page 5-31 in the Adaptech manual */
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/* this knows we are using drq 5 */
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outb (0xd6, 0xc1);
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outb (0xd4, 0x01);
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outb (as_port + AS_CONTROL, AS_CONTROL_SRST);
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/* delay a little */
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inb (0x84);
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while (inb (as_port + AS_STATUS) != (AS_STATUS_INIT | AS_STATUS_IDLE))
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;
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CHECKPOINT ('b');
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as_put_byte (AS_CMD_MAILBOX_INIT);
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as_put_byte (1); /* one mailbox out, one in */
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as_put_byte ((int)mailbox >> 16);
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as_put_byte ((int)mailbox >> 8);
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as_put_byte ((int)mailbox);
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while (inb (as_port + AS_STATUS) & AS_STATUS_INIT)
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;
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CHECKPOINT ('c');
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mailbox[0].msb = (int)ccb >> 16;
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mailbox[0].mid = (int)ccb >> 8;
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mailbox[0].lsb = (int)ccb;
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mailbox[0].cmd = 1;
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as_put_byte (AS_CMD_START_SCSI_COMMAND);
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/* wait for done */
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while (mailbox[1].cmd == 0)
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;
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CHECKPOINT ('d');
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if (mailbox[1].cmd != 1) {
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/* some error */
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CHECKPOINT ('X');
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while (1);
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}
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CHECKPOINT ('e');
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/* the optimazation that gcc uses when it knows we are jumpping
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* to a constant address is broken, so we have to use a variable
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* here
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*/
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(*f)(dev, unit, off);
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}
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int
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as_put_byte (val)
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int val;
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{
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while (inb (as_port + AS_STATUS) & AS_STATUS_CDF)
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;
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outb (as_port + AS_DATA_OUT, val);
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}
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asm ("
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ebootblkcode:
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. = 510
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.byte 0x55
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.byte 0xaa
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ebootblk: /* MUST BE EXACTLY 0x200 BIG FOR SURE */
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");
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