patch-2.4.19 linux-2.4.19/arch/ppc/boot/simple/misc-embedded.c

• Lines: 238
• Date: Fri Aug 2 17:39:43 2002
• Orig file: linux-2.4.18/arch/ppc/boot/simple/misc-embedded.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/arch/ppc/boot/simple/misc-embedded.c linux-2.4.19/arch/ppc/boot/simple/misc-embedded.c
@@ -0,0 +1,237 @@
+/*
+ * BK Id: %F% %I% %G% %U% %#%
+ *
+ * Originally adapted by Gary Thomas.  Much additional work by
+ * Cort Dougan <cort@fsmlabs.com>.  On top of that still more work by
+ * Dan Malek <dmalek@jlc.net>.
+ *
+ * Currently maintained by: Tom Rini <trini@kernel.crashing.org>
+ *
+ * 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 <linux/types.h>
+#include <linux/elf.h>
+#include <asm/bootinfo.h>
+#include <asm/mmu.h>
+#include <asm/mpc8xx.h>
+#include <asm/mpc8260.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+#include <asm/residual.h>
+
+#include "nonstdio.h"
+#include "zlib.h"
+
+/* The linker tells us where the image is. */
+extern char __image_begin, __image_end;
+extern char __ramdisk_begin, __ramdisk_end;
+extern char _end[];
+
+/* Because of the limited amount of memory on embedded, it presents
+ * loading problems.  The biggest is that we load this boot program
+ * into a relatively low memory address, and the Linux kernel Bss often
+ * extends into this space when it get loaded.  When the kernel starts
+ * and zeros the BSS space, it also writes over the information we
+ * save here and pass to the kernel (usually board info).
+ * On these boards, we grab some known memory holes to hold this information.
+ */
+char cmd_buf[256];
+char *cmd_line = cmd_buf;
+char *avail_ram;
+char *end_avail;
+char *zimage_start;
+
+/* This is for 4xx treeboot.  It provides a place for the bootrom
+ * give us a pointer to a rom environment command line.
+ */
+char *bootrom_cmdline = "";
+
+/* This is the default cmdline that will be given to the user at boot time..
+ * If none was specified at compile time, we'll give it one that should work.
+ * -- Tom */
+#ifdef CONFIG_CMDLINE_BOOL
+char compiled_string[] = CONFIG_CMDLINE;
+#endif
+char ramroot_string[] = "root=/dev/ram";
+char netroot_string[] = "root=/dev/nfs rw ip=auto";
+
+/* Serial port to use. */
+unsigned long com_port;
+
+/* We need to make sure that this is before the images to ensure
+ * that it's in a mapped location. - Tom */
+bd_t hold_resid_buf __attribute__ ((__section__ (".data.boot")));
+bd_t *hold_residual = &hold_resid_buf;
+
+extern unsigned long serial_init(int chan, bd_t *bp);
+extern void serial_close(unsigned long com_port);
+extern unsigned long start;
+extern void flush_instruction_cache(void);
+extern void gunzip(void *, int, unsigned char *, int *);
+extern void embed_config(bd_t **bp);
+
+unsigned long
+decompress_kernel(unsigned long load_addr, int num_words, unsigned long cksum, bd_t *bp)
+{
+	char *cp, ch;
+	int timer = 0, zimage_size;
+	unsigned long initrd_size;
+
+	/* First, capture the embedded board information.  Then
+	 * initialize the serial console port.
+	 */
+	embed_config(&bp);
+#ifdef CONFIG_SERIAL_CONSOLE
+	com_port = serial_init(0, bp);
+#endif
+
+	/* copy board data */
+	if (bp)
+		memcpy(hold_residual,bp,sizeof(bd_t));
+
+	/* Set end of memory available to us.  It is always the highest
+	 * memory address provided by the board information.
+	 */
+	end_avail = (char *)(bp->bi_memsize);
+
+	puts("\nloaded 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");
+	}
+
+	if ( bp ) {
+		puts("board data at: "); puthex((unsigned long)bp);
+		puts(" ");
+		puthex((unsigned long)((unsigned long)bp + sizeof(bd_t)));
+		puts("\nrelocated to:  ");
+		puthex((unsigned long)hold_residual);
+		puts(" ");
+		puthex((unsigned long)((unsigned long)hold_residual + sizeof(bd_t)));
+		puts("\n");
+	}
+
+	/*
+	 * We link ourself to an arbitrary low address.  When we run, we
+	 * relocate outself to that address.  __image_being points to
+	 * the part of the image where the zImage is. -- 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
+	 */
+	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");
+	}
+
+	/*
+	 * setup avail_ram - this is the first part of ram usable
+	 * by the uncompress code.  Anything after this program in RAM
+	 * is now fair game. -- Tom
+	 */
+	avail_ram = (char *)PAGE_ALIGN((unsigned long)_end);
+
+	puts("avail ram:     "); puthex((unsigned long)avail_ram); puts(" ");
+	puthex((unsigned long)end_avail); puts("\n");
+	puts("\nLinux/PPC load: ");
+	cp = cmd_line;
+	/* This is where we try and pick the right command line for booting.
+	 * If we were given one at compile time, use it.  It Is Right.
+	 * If we weren't, see if we have a ramdisk.  If so, thats root.
+	 * When in doubt, give them the netroot (root=/dev/nfs rw) -- Tom
+	 */
+#ifdef CONFIG_CMDLINE_BOOL
+	memcpy (cmd_line, compiled_string, sizeof(compiled_string));
+#else
+	if ( initrd_size )
+		memcpy (cmd_line, ramroot_string, sizeof(ramroot_string));
+	else
+		memcpy (cmd_line, netroot_string, sizeof(netroot_string));
+#endif
+	while ( *cp )
+		putc(*cp++);
+	while (timer++ < 5*1000) {
+		if (tstc()) {
+			while ((ch = getc()) != '\n' && ch != '\r') {
+				if (ch == '\b' || ch == '\177') {
+					if (cp != cmd_line) {
+						cp--;
+						puts("\b \b");
+					}
+				} else if (ch == '\030'		/* ^x */
+					   || ch == '\025') {	/* ^u */
+					while (cp != cmd_line) {
+						cp--;
+						puts("\b \b");
+					}
+				} else {
+					*cp++ = ch;
+					putc(ch);
+				}
+			}
+			break;  /* Exit 'timer' loop */
+		}
+		udelay(1000);  /* 1 msec */
+	}
+	*cp = 0;
+	puts("\nUncompressing Linux...");
+
+	gunzip(0, 0x400000, zimage_start, &zimage_size);
+	flush_instruction_cache();
+	puts("done.\n");
+	{
+		struct bi_record *rec;
+
+		rec = (struct bi_record *)_ALIGN((unsigned long)zimage_size +
+				(1 << 20) - 1,(1 << 20));
+
+		rec->tag = BI_FIRST;
+		rec->size = sizeof(struct bi_record);
+		rec = (struct bi_record *)((unsigned long)rec + rec->size);
+
+		rec->tag = BI_CMD_LINE;
+		memcpy( (char *)rec->data, cmd_line, strlen(cmd_line)+1);
+		rec->size = sizeof(struct bi_record) + strlen(cmd_line) + 1;
+		rec = (struct bi_record *)((unsigned long)rec + rec->size);
+
+		if ( initrd_size ) {
+			rec->tag = BI_INITRD;
+			rec->data[0] = (unsigned long)(&__ramdisk_begin);
+			rec->data[1] = initrd_size;
+			rec->size = sizeof(struct bi_record) + 2 *
+				sizeof(unsigned long);
+			rec = (struct bi_record *)((unsigned long)rec +
+					rec->size);
+		}
+
+		rec->tag = BI_LAST;
+		rec->size = sizeof(struct bi_record);
+		rec = (struct bi_record *)((unsigned long)rec + rec->size);
+	}
+	puts("Now booting the kernel\n");
+	serial_close(com_port);
+
+	return (unsigned long)hold_residual;
+}