1/* 2 * BK Id: %F% %I% %G% %U% %#% 3 * 4 * Originally adapted by Gary Thomas. Much additional work by 5 * Cort Dougan <cort@fsmlabs.com>. On top of that still more work by 6 * Dan Malek <dmalek@jlc.net>. 7 * 8 * Currently maintained by: Tom Rini <trini@kernel.crashing.org> 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the 12 * Free Software Foundation; either version 2 of the License, or (at your 13 * option) any later version. 14 * 15 */ 16 17#include <linux/config.h> 18#include <linux/types.h> 19#include <linux/elf.h> 20#include <asm/bootinfo.h> 21#include <asm/mmu.h> 22#include <asm/mpc8xx.h> 23#include <asm/mpc8260.h> 24#include <asm/page.h> 25#include <asm/processor.h> 26#include <asm/residual.h> 27 28#include "nonstdio.h" 29#include "zlib.h" 30 31/* The linker tells us where the image is. */ 32extern char __image_begin, __image_end; 33extern char __ramdisk_begin, __ramdisk_end; 34extern char _end[]; 35 36/* Because of the limited amount of memory on embedded, it presents 37 * loading problems. The biggest is that we load this boot program 38 * into a relatively low memory address, and the Linux kernel Bss often 39 * extends into this space when it get loaded. When the kernel starts 40 * and zeros the BSS space, it also writes over the information we 41 * save here and pass to the kernel (usually board info). 42 * On these boards, we grab some known memory holes to hold this information. 43 */ 44char cmd_buf[256]; 45char *cmd_line = cmd_buf; 46char *avail_ram; 47char *end_avail; 48char *zimage_start; 49 50/* This is for 4xx treeboot. It provides a place for the bootrom 51 * give us a pointer to a rom environment command line. 52 */ 53char *bootrom_cmdline = ""; 54 55/* This is the default cmdline that will be given to the user at boot time.. 56 * If none was specified at compile time, we'll give it one that should work. 57 * -- Tom */ 58#ifdef CONFIG_CMDLINE_BOOL 59char compiled_string[] = CONFIG_CMDLINE; 60#endif 61char ramroot_string[] = "root=/dev/ram"; 62char netroot_string[] = "root=/dev/nfs rw ip=on"; 63 64/* Serial port to use. */ 65unsigned long com_port; 66 67/* We need to make sure that this is before the images to ensure 68 * that it's in a mapped location. - Tom */ 69bd_t hold_resid_buf __attribute__ ((__section__ (".data.boot"))); 70bd_t *hold_residual = &hold_resid_buf; 71 72extern unsigned long serial_init(int chan, bd_t *bp); 73extern void serial_close(unsigned long com_port); 74extern unsigned long start; 75extern void flush_instruction_cache(void); 76extern void gunzip(void *, int, unsigned char *, int *); 77extern void embed_config(bd_t **bp); 78 79unsigned long 80decompress_kernel(unsigned long load_addr, int num_words, unsigned long cksum, bd_t *bp) 81{ 82 char *cp, ch; 83 int timer = 0, zimage_size; 84 unsigned long initrd_size; 85 86 /* First, capture the embedded board information. Then 87 * initialize the serial console port. 88 */ 89 embed_config(&bp); 90#ifdef CONFIG_SERIAL_CONSOLE 91 com_port = serial_init(0, bp); 92#endif 93 94 /* copy board data */ 95 if (bp) 96 memcpy(hold_residual,bp,sizeof(bd_t)); 97 98 /* Set end of memory available to us. It is always the highest 99 * memory address provided by the board information. 100 */ 101 end_avail = (char *)(bp->bi_memsize); 102 103 puts("\nloaded at: "); puthex(load_addr); 104 puts(" "); puthex((unsigned long)(load_addr + (4*num_words))); puts("\n"); 105 if ( (unsigned long)load_addr != (unsigned long)&start ) { 106 puts("relocated to: "); puthex((unsigned long)&start); 107 puts(" "); 108 puthex((unsigned long)((unsigned long)&start + (4*num_words))); 109 puts("\n"); 110 } 111 112 if ( bp ) { 113 puts("board data at: "); puthex((unsigned long)bp); 114 puts(" "); 115 puthex((unsigned long)((unsigned long)bp + sizeof(bd_t))); 116 puts("\nrelocated to: "); 117 puthex((unsigned long)hold_residual); 118 puts(" "); 119 puthex((unsigned long)((unsigned long)hold_residual + sizeof(bd_t))); 120 puts("\n"); 121 } 122 123 /* 124 * We link ourself to an arbitrary low address. When we run, we 125 * relocate outself to that address. __image_being points to 126 * the part of the image where the zImage is. -- Tom 127 */ 128 zimage_start = (char *)(unsigned long)(&__image_begin); 129 zimage_size = (unsigned long)(&__image_end) - 130 (unsigned long)(&__image_begin); 131 132 initrd_size = (unsigned long)(&__ramdisk_end) - 133 (unsigned long)(&__ramdisk_begin); 134 135 /* 136 * The zImage and initrd will be between start and _end, so they've 137 * already been moved once. We're good to go now. -- Tom 138 */ 139 puts("zimage at: "); puthex((unsigned long)zimage_start); 140 puts(" "); puthex((unsigned long)(zimage_size+zimage_start)); 141 puts("\n"); 142 143 if ( initrd_size ) { 144 puts("initrd at: "); 145 puthex((unsigned long)(&__ramdisk_begin)); 146 puts(" "); puthex((unsigned long)(&__ramdisk_end));puts("\n"); 147 } 148 149 /* 150 * setup avail_ram - this is the first part of ram usable 151 * by the uncompress code. Anything after this program in RAM 152 * is now fair game. -- Tom 153 */ 154 avail_ram = (char *)PAGE_ALIGN((unsigned long)_end); 155 156 puts("avail ram: "); puthex((unsigned long)avail_ram); puts(" "); 157 puthex((unsigned long)end_avail); puts("\n"); 158 puts("\nLinux/PPC load: "); 159 cp = cmd_line; 160 /* This is where we try and pick the right command line for booting. 161 * If we were given one at compile time, use it. It Is Right. 162 * If we weren't, see if we have a ramdisk. If so, thats root. 163 * When in doubt, give them the netroot (root=/dev/nfs rw) -- Tom 164 */ 165#ifdef CONFIG_CMDLINE_BOOL 166 memcpy (cmd_line, compiled_string, sizeof(compiled_string)); 167#else 168 if ( initrd_size ) 169 memcpy (cmd_line, ramroot_string, sizeof(ramroot_string)); 170 else 171 memcpy (cmd_line, netroot_string, sizeof(netroot_string)); 172#endif 173 while ( *cp ) 174 putc(*cp++); 175#if defined(CONFIG_SERIAL_CONSOLE) || defined(CONFIG_VGA_CONSOLE) 176 /* 177 * If they have a console, allow them to edit the command line. 178 * Otherwise, don't bother wasting the five seconds. 179 */ 180 while (timer++ < 5*1000) { 181 if (tstc()) { 182 while ((ch = getc()) != '\n' && ch != '\r') { 183 if (ch == '\b' || ch == '\177') { 184 if (cp != cmd_line) { 185 cp--; 186 puts("\b \b"); 187 } 188 } else if (ch == '\030' /* ^x */ 189 || ch == '\025') { /* ^u */ 190 while (cp != cmd_line) { 191 cp--; 192 puts("\b \b"); 193 } 194 } else { 195 *cp++ = ch; 196 putc(ch); 197 } 198 } 199 break; /* Exit 'timer' loop */ 200 } 201 udelay(1000); /* 1 msec */ 202 } 203#endif 204 *cp = 0; 205 puts("\nUncompressing Linux..."); 206 207 gunzip(0, 0x400000, zimage_start, &zimage_size); 208 flush_instruction_cache(); 209 puts("done.\n"); 210 { 211 struct bi_record *rec; 212 213 rec = (struct bi_record *)_ALIGN((unsigned long)zimage_size + 214 (1 << 20) - 1,(1 << 20)); 215 216 rec->tag = BI_FIRST; 217 rec->size = sizeof(struct bi_record); 218 rec = (struct bi_record *)((unsigned long)rec + rec->size); 219 220 rec->tag = BI_CMD_LINE; 221 memcpy( (char *)rec->data, cmd_line, strlen(cmd_line)+1); 222 rec->size = sizeof(struct bi_record) + strlen(cmd_line) + 1; 223 rec = (struct bi_record *)((unsigned long)rec + rec->size); 224 225 if ( initrd_size ) { 226 rec->tag = BI_INITRD; 227 rec->data[0] = (unsigned long)(&__ramdisk_begin); 228 rec->data[1] = initrd_size; 229 rec->size = sizeof(struct bi_record) + 2 * 230 sizeof(unsigned long); 231 rec = (struct bi_record *)((unsigned long)rec + 232 rec->size); 233 } 234 235 rec->tag = BI_LAST; 236 rec->size = sizeof(struct bi_record); 237 rec = (struct bi_record *)((unsigned long)rec + rec->size); 238 } 239 puts("Now booting the kernel\n"); 240 serial_close(com_port); 241 242 return (unsigned long)hold_residual; 243} 244