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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc/boot/simple/misc-embedded.c
downloadlinux-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
linux-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/ppc/boot/simple/misc-embedded.c')
-rw-r--r--arch/ppc/boot/simple/misc-embedded.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/arch/ppc/boot/simple/misc-embedded.c b/arch/ppc/boot/simple/misc-embedded.c
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index 000000000000..3865f3f8dcd1
--- /dev/null
+++ b/arch/ppc/boot/simple/misc-embedded.c
@@ -0,0 +1,275 @@
+/*
+ * 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/config.h>
+#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 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;
+ 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;
+}