main.c
/*
* Copyright (C) Paul Mackerras 1997.
*
* Updates for PPC64 by Todd Inglett, Dave Engebretsen & Peter Bergner.
*
* 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 <stdarg.h>
#include <stddef.h>
#include "elf.h"
#include "page.h"
#include "string.h"
#include "stdio.h"
#include "ops.h"
#include "reg.h"
struct addr_range {
void *addr;
unsigned long size;
};
#undef DEBUG
static struct addr_range prep_kernel(void)
{
char elfheader[256];
unsigned char *vmlinuz_addr = (unsigned char *)_vmlinux_start;
unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
void *addr = 0;
struct elf_info ei;
long len;
int uncompressed_image = 0;
len = partial_decompress(vmlinuz_addr, vmlinuz_size,
elfheader, sizeof(elfheader), 0);
/* assume uncompressed data if -1 is returned */
if (len == -1) {
uncompressed_image = 1;
memcpy(elfheader, vmlinuz_addr, sizeof(elfheader));
printf("No valid compressed data found, assume uncompressed data\n\r");
}
if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
if (platform_ops.image_hdr)
platform_ops.image_hdr(elfheader);
/* We need to alloc the memsize: gzip will expand the kernel
* text/data, then possible rubbish we don't care about. But
* the kernel bss must be claimed (it will be zero'd by the
* kernel itself)
*/
printf("Allocating 0x%lx bytes for kernel...\n\r", ei.memsize);
if (platform_ops.vmlinux_alloc) {
addr = platform_ops.vmlinux_alloc(ei.memsize);
} else {
/*
* Check if the kernel image (without bss) would overwrite the
* bootwrapper. The device tree has been moved in fdt_init()
* to an area allocated with malloc() (somewhere past _end).
*/
if ((unsigned long)_start < ei.loadsize)
fatal("Insufficient memory for kernel at address 0!"
" (_start=%p, uncompressed size=%08lx)\n\r",
_start, ei.loadsize);
if ((unsigned long)_end < ei.memsize)
fatal("The final kernel image would overwrite the "
"device tree\n\r");
}
if (uncompressed_image) {
memcpy(addr, vmlinuz_addr + ei.elfoffset, ei.loadsize);
printf("0x%lx bytes of uncompressed data copied\n\r",
ei.loadsize);
goto out;
}
/* Finally, decompress the kernel */
printf("Decompressing (0x%p <- 0x%p:0x%p)...\n\r", addr,
vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
len = partial_decompress(vmlinuz_addr, vmlinuz_size,
addr, ei.loadsize, ei.elfoffset);
if (len < 0)
fatal("Decompression failed with error code %ld\n\r", len);
if (len != ei.loadsize)
fatal("Decompression error: got 0x%lx bytes, expected 0x%lx.\n\r",
len, ei.loadsize);
printf("Done! Decompressed 0x%lx bytes\n\r", len);
out:
flush_cache(addr, ei.loadsize);
return (struct addr_range){addr, ei.memsize};
}
static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
unsigned long initrd_addr,
unsigned long initrd_size)
{
/* If we have an image attached to us, it overrides anything
* supplied by the loader. */
if (_initrd_end > _initrd_start) {
printf("Attached initrd image at 0x%p-0x%p\n\r",
_initrd_start, _initrd_end);
initrd_addr = (unsigned long)_initrd_start;
initrd_size = _initrd_end - _initrd_start;
} else if (initrd_size > 0) {
printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
initrd_addr, initrd_addr + initrd_size);
}
/* If there's no initrd at all, we're done */
if (! initrd_size)
return (struct addr_range){0, 0};
/*
* If the initrd is too low it will be clobbered when the
* kernel relocates to its final location. In this case,
* allocate a safer place and move it.
*/
if (initrd_addr < vmlinux.size) {
void *old_addr = (void *)initrd_addr;
printf("Allocating 0x%lx bytes for initrd ...\n\r",
initrd_size);
initrd_addr = (unsigned long)malloc(initrd_size);
if (! initrd_addr)
fatal("Can't allocate memory for initial "
"ramdisk !\n\r");
printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
initrd_addr, old_addr, initrd_size);
memmove((void *)initrd_addr, old_addr, initrd_size);
}
printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
/* Tell the kernel initrd address via device tree */
setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
return (struct addr_range){(void *)initrd_addr, initrd_size};
}
/* A buffer that may be edited by tools operating on a zImage binary so as to
* edit the command line passed to vmlinux (by setting /chosen/bootargs).
* The buffer is put in it's own section so that tools may locate it easier.
*/
static char cmdline[BOOT_COMMAND_LINE_SIZE]
__attribute__((__section__("__builtin_cmdline")));
static void prep_cmdline(void *chosen)
{
unsigned int getline_timeout = 5000;
int v;
int n;
/* Wait-for-input time */
n = getprop(chosen, "linux,cmdline-timeout", &v, sizeof(v));
if (n == sizeof(v))
getline_timeout = v;
if (cmdline[0] == '\0')
getprop(chosen, "bootargs", cmdline, BOOT_COMMAND_LINE_SIZE-1);
printf("\n\rLinux/PowerPC load: %s", cmdline);
/* If possible, edit the command line */
if (console_ops.edit_cmdline && getline_timeout)
console_ops.edit_cmdline(cmdline, BOOT_COMMAND_LINE_SIZE, getline_timeout);
printf("\n\r");
/* Put the command line back into the devtree for the kernel */
setprop_str(chosen, "bootargs", cmdline);
}
struct platform_ops platform_ops;
struct dt_ops dt_ops;
struct console_ops console_ops;
struct loader_info loader_info;
void start(void)
{
struct addr_range vmlinux, initrd;
kernel_entry_t kentry;
unsigned long ft_addr = 0;
void *chosen;
/* Do this first, because malloc() could clobber the loader's
* command line. Only use the loader command line if a
* built-in command line wasn't set by an external tool */
if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
memmove(cmdline, loader_info.cmdline,
min(loader_info.cmdline_len, BOOT_COMMAND_LINE_SIZE-1));
if (console_ops.open && (console_ops.open() < 0))
exit();
if (platform_ops.fixups)
platform_ops.fixups();
printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
_start, get_sp());
/* Ensure that the device tree has a /chosen node */
chosen = finddevice("/chosen");
if (!chosen)
chosen = create_node(NULL, "chosen");
vmlinux = prep_kernel();
initrd = prep_initrd(vmlinux, chosen,
loader_info.initrd_addr, loader_info.initrd_size);
prep_cmdline(chosen);
printf("Finalizing device tree...");
if (dt_ops.finalize)
ft_addr = dt_ops.finalize();
if (ft_addr)
printf(" flat tree at 0x%lx\n\r", ft_addr);
else
printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
if (console_ops.close)
console_ops.close();
kentry = (kernel_entry_t) vmlinux.addr;
if (ft_addr) {
if(platform_ops.kentry)
platform_ops.kentry(ft_addr, vmlinux.addr);
else
kentry(ft_addr, 0, NULL);
}
else
kentry((unsigned long)initrd.addr, initrd.size,
loader_info.promptr);
/* console closed so printf in fatal below may not work */
fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
}