/* * 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_CMDLINEchar *cmdline = CONFIG_CMDLINE;#elsechar *cmdline = "";#endif/* Function Prototypes */extern void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp);voidkick_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();}