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misc.c

/*
 * Misc. bootloader code for many machines.  This assumes you have are using
 * a 6xx/7xx/74xx CPU in your machine.  This assumes the chunk of memory
 * below 8MB is free.  Finally, it assumes you have a NS16550-style uart for
 * your serial console.  If a machine meets these requirements, it can quite
 * likely use this code during boot.
 *
 * Author: Matt Porter <mporter@mvista.com>
 * Derived from arch/ppc/boot/prep/misc.c
 *
 * 2001 (c) MontaVista, Software, Inc.  This file is licensed under
 * the terms of the GNU General Public License version 2.  This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 */

#include <linux/types.h>
#include <linux/string.h>

#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/bootinfo.h>
#ifdef CONFIG_4xx
#include <asm/ibm4xx.h>
#endif
#include <asm/reg.h>

#include "nonstdio.h"

/* Default cmdline */
#ifdef CONFIG_CMDLINE
#define CMDLINE CONFIG_CMDLINE
#else
#define CMDLINE ""
#endif

/* Keyboard (and VGA console)? */
#ifdef CONFIG_VGA_CONSOLE
#define HAS_KEYB 1
#else
#define HAS_KEYB 0
#endif

/* Will / Can the user give input?
 */
#if (defined(CONFIG_SERIAL_8250_CONSOLE) \
      || defined(CONFIG_VGA_CONSOLE) \
      || defined(CONFIG_SERIAL_MPC52xx_CONSOLE) \
      || defined(CONFIG_SERIAL_MPSC_CONSOLE))
#define INTERACTIVE_CONSOLE   1
#endif

char *avail_ram;
char *end_avail;
char *zimage_start;
char cmd_preset[] = CMDLINE;
char cmd_buf[256];
char *cmd_line = cmd_buf;
int keyb_present = HAS_KEYB;
int zimage_size;

unsigned long com_port;
unsigned long initrd_size = 0;

/* The linker tells us various locations in the image */
extern char __image_begin, __image_end;
extern char __ramdisk_begin, __ramdisk_end;
extern char _end[];
/* Original location */
extern unsigned long start;

extern int CRT_tstc(void);
extern unsigned long serial_init(int chan, void *ignored);
extern void serial_close(unsigned long com_port);
extern void gunzip(void *, int, unsigned char *, int *);
extern void serial_fixups(void);

/* Allow get_mem_size to be hooked into.  This is the default. */
unsigned long __attribute__ ((weak))
get_mem_size(void)
{
      return 0;
}

#if defined(CONFIG_40x)
#define PPC4xx_EMAC0_MR0      EMAC0_BASE
#endif

#if defined(CONFIG_44x) && defined(PPC44x_EMAC0_MR0)
#define PPC4xx_EMAC0_MR0      PPC44x_EMAC0_MR0
#endif

struct bi_record *
decompress_kernel(unsigned long load_addr, int num_words, unsigned long cksum)
{
#ifdef INTERACTIVE_CONSOLE
      int timer = 0;
      char ch;
#endif
      char *cp;
      struct bi_record *rec;
      unsigned long initrd_loc = 0, TotalMemory = 0;

#if defined(CONFIG_SERIAL_8250_CONSOLE) || defined(CONFIG_SERIAL_MPSC_CONSOLE)
      com_port = serial_init(0, NULL);
#endif

#if defined(PPC4xx_EMAC0_MR0)
      /* Reset MAL */
      mtdcr(DCRN_MALCR(DCRN_MAL_BASE), MALCR_MMSR);
      /* Wait for reset */
      while (mfdcr(DCRN_MALCR(DCRN_MAL_BASE)) & MALCR_MMSR) {};
      /* Reset EMAC */
      *(volatile unsigned long *)PPC4xx_EMAC0_MR0 = 0x20000000;
      __asm__ __volatile__("eieio");
#endif

      /*
       * Call get_mem_size(), which is memory controller dependent,
       * and we must have the correct file linked in here.
       */
      TotalMemory = get_mem_size();

      /* assume the chunk below 8M is free */
      end_avail = (char *)0x00800000;

      /*
       * Reveal where we were loaded at and where we
       * were relocated to.
       */
      puts("loaded at:     "); puthex(load_addr);
      puts(" "); puthex((unsigned long)(load_addr + (4*num_words)));
      puts("\n");
      if ( (unsigned long)load_addr != (unsigned long)&start )
      {
            puts("relocated to:  "); puthex((unsigned long)&start);
            puts(" ");
            puthex((unsigned long)((unsigned long)&start + (4*num_words)));
            puts("\n");
      }

      /*
       * We link ourself to 0x00800000.  When we run, we relocate
       * ourselves there.  So we just need __image_begin for the
       * start. -- Tom
       */
      zimage_start = (char *)(unsigned long)(&__image_begin);
      zimage_size = (unsigned long)(&__image_end) -
                  (unsigned long)(&__image_begin);

      initrd_size = (unsigned long)(&__ramdisk_end) -
            (unsigned long)(&__ramdisk_begin);

      /*
       * The zImage and initrd will be between start and _end, so they've
       * already been moved once.  We're good to go now. -- Tom
       */
      avail_ram = (char *)PAGE_ALIGN((unsigned long)_end);
      puts("zimage at:     "); puthex((unsigned long)zimage_start);
      puts(" "); puthex((unsigned long)(zimage_size+zimage_start));
      puts("\n");

      if ( initrd_size ) {
            puts("initrd at:     ");
            puthex((unsigned long)(&__ramdisk_begin));
            puts(" "); puthex((unsigned long)(&__ramdisk_end));puts("\n");
      }

#ifndef CONFIG_40x /* don't overwrite the 40x image located at 0x00400000! */
      avail_ram = (char *)0x00400000;
#endif
      end_avail = (char *)0x00800000;
      puts("avail ram:     "); puthex((unsigned long)avail_ram); puts(" ");
      puthex((unsigned long)end_avail); puts("\n");

      if (keyb_present)
            CRT_tstc();  /* Forces keyboard to be initialized */

      /* Display standard Linux/PPC boot prompt for kernel args */
      puts("\nLinux/PPC load: ");
      cp = cmd_line;
      memcpy (cmd_line, cmd_preset, sizeof(cmd_preset));
      while ( *cp ) putc(*cp++);

#ifdef INTERACTIVE_CONSOLE
      /*
       * If they have a console, allow them to edit the command line.
       * Otherwise, don't bother wasting the five seconds.
       */
      while (timer++ < 5*1000) {
            if (tstc()) {
                  while ((ch = getc()) != '\n' && ch != '\r') {
                        /* Test for backspace/delete */
                        if (ch == '\b' || ch == '\177') {
                              if (cp != cmd_line) {
                                    cp--;
                                    puts("\b \b");
                              }
                        /* Test for ^x/^u (and wipe the line) */
                        } else if (ch == '\030' || ch == '\025') {
                              while (cp != cmd_line) {
                                    cp--;
                                    puts("\b \b");
                              }
                        } else {
                              *cp++ = ch;
                              putc(ch);
                        }
                  }
                  break;  /* Exit 'timer' loop */
            }
            udelay(1000);  /* 1 msec */
      }
      *cp = 0;
#endif
      puts("\n");

      puts("Uncompressing Linux...");
      gunzip(NULL, 0x400000, zimage_start, &zimage_size);
      puts("done.\n");

      /* get the bi_rec address */
      rec = bootinfo_addr(zimage_size);

      /* We need to make sure that the initrd and bi_recs do not
       * overlap. */
      if ( initrd_size ) {
            unsigned long rec_loc = (unsigned long) rec;
            initrd_loc = (unsigned long)(&__ramdisk_begin);
            /* If the bi_recs are in the middle of the current
             * initrd, move the initrd to the next MB
             * boundary. */
            if ((rec_loc > initrd_loc) &&
                        ((initrd_loc + initrd_size) > rec_loc)) {
                  initrd_loc = _ALIGN((unsigned long)(zimage_size)
                              + (2 << 20) - 1, (2 << 20));
                  memmove((void *)initrd_loc, &__ramdisk_begin,
                         initrd_size);
                  puts("initrd moved:  "); puthex(initrd_loc);
                  puts(" "); puthex(initrd_loc + initrd_size);
                  puts("\n");
            }
      }

      bootinfo_init(rec);
      if ( TotalMemory )
            bootinfo_append(BI_MEMSIZE, sizeof(int), (void*)&TotalMemory);

      bootinfo_append(BI_CMD_LINE, strlen(cmd_line)+1, (void*)cmd_line);

      /* add a bi_rec for the initrd if it exists */
      if (initrd_size) {
            unsigned long initrd[2];

            initrd[0] = initrd_loc;
            initrd[1] = initrd_size;

            bootinfo_append(BI_INITRD, sizeof(initrd), &initrd);
      }
      puts("Now booting the kernel\n");
      serial_close(com_port);

      return rec;
}

void __attribute__ ((weak))
board_isa_init(void)
{
}

/* Allow decompress_kernel to be hooked into.  This is the default. */
void * __attribute__ ((weak))
load_kernel(unsigned long load_addr, int num_words, unsigned long cksum,
            void *ign1, void *ign2)
{
            board_isa_init();
            return decompress_kernel(load_addr, num_words, cksum);
}

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