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/*
* BK Id: SCCS/s.main.c 1.9 06/15/01 13:16:10 paulus
*/
/*
* Copyright (c) 1997 Paul Mackerras <paulus@cs.anu.edu.au>
* Initial Power Macintosh COFF version.
* Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
* Modifications for an ELF-based IBM evaluation board version.
* Copyright 2000-2001 MontaVista Software Inc.
* PPC405GP modifications
* Author: MontaVista Software, Inc.
* frank_rowand@mvista.com or source@mvista.com
* debbie_chu@mvista.com
*
* Module name: main.c
*
* Description:
* This module does most of the real work for the boot loader. It
* checks the variables holding the absolute start address and size
* of the Linux kernel "image" and initial RAM disk "initrd" sections
* and if they are present, moves them to their "proper" locations.
*
* For the Linux kernel, "proper" is physical address 0x00000000.
* For the RAM disk, "proper" is the image's size below the top
* of physical memory. The Linux kernel may be in either raw
* binary form or compressed with GNU zip (aka gzip).
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/config.h>
#include <asm/ppc4xx.h>
#include "nonstdio.h"
#include "irSect.h"
#if defined(CONFIG_SERIAL_CONSOLE)
#include "ns16550.h"
#endif /* CONFIG_SERIAL_CONSOLE */
/* Preprocessor Defines */
/*
* Location of the IBM boot ROM function pointer address for retrieving
* the board information structure.
*/
#define BOARD_INFO_VECTOR 0xFFFE0B50
/*
* Warning: the board_info doesn't contain valid data until get_board_info()
* gets called in start().
*/
#define RAM_SIZE board_info.bi_memsize
#define RAM_PBASE 0x00000000
#define RAM_PEND (RAM_PBASE + RAM_SIZE)
#define RAM_VBASE 0xC0000000
#define RAM_VEND (RAM_VBASE + RAM_SIZE)
#define RAM_START RAM_PBASE
#define RAM_END RAM_PEND
#define RAM_FREE (imageSect_start + imageSect_size + initrdSect_size)
#define PROG_START RAM_START
/* Function Macros */
#define ALIGN_UP(x, align) (((x) + ((align) - 1)) & ~((align) - 1))
/* Global Variables */
/* Needed by zalloc and zfree for allocating memory */
char *avail_ram; /* Indicates start of RAM available for heap */
char *end_avail; /* Indicates end of RAM available for heap */
/* Needed for serial I/O.
*/
extern unsigned long *com_port;
bd_t board_info;
/*
** The bootrom may change bootrom_cmdline to point to a buffer in the
** bootrom.
*/
char *bootrom_cmdline = "";
char treeboot_bootrom_cmdline[512];
#ifdef CONFIG_CMDLINE
char *cmdline = CONFIG_CMDLINE;
#else
char *cmdline = "";
#endif
/* Function Prototypes */
extern void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp);
void
kick_watchdog(void)
{
#ifdef CONFIG_405GP
mtspr(SPRN_TSR, (TSR_ENW | TSR_WIS));
#endif
}
void start(void)
{
void *options;
int ns, oh, i;
unsigned long sa, len;
void *dst;
unsigned char *im;
unsigned long initrd_start, initrd_size;
bd_t *(*get_board_info)(void) =
(bd_t *(*)(void))(*(unsigned long *)BOARD_INFO_VECTOR);
bd_t *bip = NULL;
com_port = (struct NS16550 *)serial_init(0);
#ifdef CONFIG_405GP
/* turn off on-chip ethernet */
/* This is to fix a problem with early walnut bootrom. */
{
/* Physical mapping of ethernet register space. */
static struct ppc405_enet_regs *ppc405_enet_regp =
(struct ppc405_enet_regs *)PPC405_EM0_REG_ADDR;
mtdcr(DCRN_MALCR, MALCR_MMSR); /* 1st reset MAL */
while (mfdcr(DCRN_MALCR) & MALCR_MMSR) {}; /* wait for the reset */
ppc405_enet_regp->em0mr0 = 0x20000000; /* then reset EMAC */
}
#endif
if ((bip = get_board_info()) != NULL)
memcpy(&board_info, bip, sizeof(bd_t));
/* Init RAM disk (initrd) section */
kick_watchdog();
if (initrdSect_start != 0 && (initrd_size = initrdSect_size) != 0) {
initrd_start = (RAM_END - initrd_size) & ~0xFFF;
_printk("Initial RAM disk at 0x%08x (%u bytes)\n",
initrd_start, initrd_size);
memcpy((char *)initrd_start,
(char *)(initrdSect_start),
initrdSect_size);
end_avail = (char *)initrd_start;
} else {
initrd_start = initrd_size = 0;
end_avail = (char *)RAM_END;
}
/* Linux kernel image section */
kick_watchdog();
im = (unsigned char *)(imageSect_start);
len = imageSect_size;
dst = (void *)PROG_START;
/* Check for the gzip archive magic numbers */
if (im[0] == 0x1f && im[1] == 0x8b) {
/* The gunzip routine needs everything nice and aligned */
void *cp = (void *)ALIGN_UP(RAM_FREE, 8);
avail_ram = (void *)(cp + ALIGN_UP(len, 8)); /* used by zalloc() */
memcpy(cp, im, len);
/* I'm not sure what the 0x200000 parameter is for, but it works. */
/* It tells gzip the end of the area you wish to reserve, and it
* can use data past that point....unfortunately, this value
* isn't big enough (luck ran out). -- Dan
*/
gunzip(dst, 0x400000, cp, (int *)&len);
} else {
memmove(dst, im, len);
}
kick_watchdog();
flush_cache(dst, len);
sa = (unsigned long)dst;
(*(void (*)())sa)(&board_info,
initrd_start,
initrd_start + initrd_size,
cmdline,
cmdline + strlen(cmdline));
pause();
}
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