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linux-stable-rt/arch/ppc/boot/simple/misc-embedded.c

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C
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/*
* 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>
*/
#include <linux/types.h>
#include <linux/string.h>
#include <asm/bootinfo.h>
#include <asm/mmu.h>
#include <asm/page.h>
#include <asm/residual.h>
#if defined(CONFIG_4xx)
#include <asm/ibm4xx.h>
#elif defined(CONFIG_8xx)
#include <asm/mpc8xx.h>
#elif defined(CONFIG_8260)
#include <asm/mpc8260.h>
#endif
#include "nonstdio.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=on";
/* 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);
/* Weak function for boards which don't need to build the
* board info struct because they are using PPCBoot/U-Boot.
*/
void __attribute__ ((weak))
embed_config(bd_t **bdp)
{
}
unsigned long
load_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);
#if defined(CONFIG_SERIAL_CPM_CONSOLE) || defined(CONFIG_SERIAL_8250_CONSOLE)
com_port = serial_init(0, bp);
#endif
/* Grab some space for the command line and board info. Since
* we no longer use the ELF header, but it was loaded, grab
* that space.
*/
#ifdef CONFIG_MBX
/* Because of the way the MBX loads the ELF image, we can't
* tell where we started. We read a magic variable from the NVRAM
* that gives us the intermediate buffer load address.
*/
load_addr = *(uint *)0xfa000020;
load_addr += 0x10000; /* Skip ELF header */
#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 ourself 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;
unsigned long initrd_loc = 0;
unsigned long rec_loc = _ALIGN((unsigned long)(zimage_size) +
(1 << 20) - 1, (1 << 20));
rec = (struct bi_record *)rec_loc;
/* We need to make sure that the initrd and bi_recs do not
* overlap. */
if ( initrd_size ) {
initrd_loc = (unsigned long)(&__ramdisk_begin);
/* If the bi_recs are in the middle of the current
* initrd, move the initrd to the next MB
* boundary. */
if ((rec_loc > initrd_loc) &&
((initrd_loc + initrd_size)
> rec_loc)) {
initrd_loc = _ALIGN((unsigned long)(zimage_size)
+ (2 << 20) - 1, (2 << 20));
memmove((void *)initrd_loc, &__ramdisk_begin,
initrd_size);
puts("initrd moved: "); puthex(initrd_loc);
puts(" "); puthex(initrd_loc + initrd_size);
puts("\n");
}
}
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] = initrd_loc;
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");
#if defined(CONFIG_SERIAL_CPM_CONSOLE) || defined(CONFIG_SERIAL_8250_CONSOLE)
serial_close(com_port);
#endif
return (unsigned long)hold_residual;
}
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