/* * arch/ppc/common/misc-simple.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 * * Copyright 2001 MontaVista Software Inc. * * 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/types.h>#include <linux/elf.h>#include <linux/config.h>#include <asm/page.h>#include <asm/processor.h>#include <asm/mmu.h>#include "nonstdio.h"#include "zlib.h"unsigned long com_port;char *avail_ram;char *end_avail;extern char _end[];#ifdef CONFIG_CMDLINE#define CMDLINE CONFIG_CMDLINE#else#define CMDLINE ""#endifchar cmd_preset[] = CMDLINE;char cmd_buf[256];char *cmd_line = cmd_buf;unsigned long initrd_start = 0, initrd_end = 0;/* These values must be variables.  If not, the compiler optimizer * will remove some code, causing the size of the code to vary * when these values are zero.  This is bad because we first * compile with these zero to determine the size and offsets * in an image, than compile again with these set to the proper * discovered value. */unsigned int initrd_offset, initrd_size;char *zimage_start;int zimage_size;extern void gunzip(void *, int, unsigned char *, int *);extern unsigned long serial_init(int chan);voiddecompress_kernel(unsigned long load_addr, int num_words, unsigned long cksum){	int timer = 0;	extern unsigned long start;	char *cp, ch;	com_port = serial_init(0);	/* 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 have to subtract 0x10000 here to correct for objdump including	   the size of the elf header which we strip -- Cort */	zimage_start = (char *)(load_addr - 0x10000 + ZIMAGE_OFFSET);	zimage_size = ZIMAGE_SIZE;	initrd_offset = INITRD_OFFSET;	initrd_size = INITRD_SIZE;	if ( initrd_offset )		initrd_start = load_addr - 0x10000 + initrd_offset;	else		initrd_start = 0;	initrd_end = initrd_size + initrd_start;	/* Relocate the zImage */	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");	memcpy( (void *)avail_ram, (void *)zimage_start, zimage_size );	zimage_start = (char *)avail_ram;	puts("relocated to:  "); puthex((unsigned long)zimage_start);	puts(" ");	puthex((unsigned long)zimage_size+(unsigned long)zimage_start);	puts("\n");	if ( initrd_start ) {		puts("initrd at:     "); puthex(initrd_start);		puts(" "); puthex(initrd_end); puts("\n");		/* relocate initrd */		avail_ram = (char *)PAGE_ALIGN((unsigned long)zimage_size + 				(unsigned long)zimage_start);		memcpy( (void *)avail_ram, (void *)initrd_start, initrd_size );		initrd_start = (unsigned long)avail_ram;		initrd_end = initrd_start + initrd_size;		puts("relocated to:  "); puthex(initrd_start);		puts(" "); puthex(initrd_end); puts("\n");	}	avail_ram = (char *)0x00400000;	end_avail = (char *)0x00800000;	puts("avail ram:     "); puthex((unsigned long)avail_ram); puts(" ");	puthex((unsigned long)end_avail); puts("\n");	/* 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++);	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;	puts("\n");	/* mappings on early boot can only handle 16M */	if ( (u32)(cmd_line) > (16<<20))		puts("cmd_line located > 16M\n");	puts("Uncompressing Linux...");	gunzip(0, 0x400000, zimage_start, &zimage_size);	puts("done.\n");	puts("Now booting the kernel\n");}