kernel-ark/arch/powerpc/boot/main.c
David Gibson 35af89eb49 [POWERPC] Cleanup zImage handling of kernel entry with flat device tree
This makes 2 changes to clean up the flat device tree handling
logic in the zImage wrapper.

First, there were two callbacks from the dt_ops structure used for
producing a final flat tree to pass to the kerne: dt_ops.ft_pack()
which packed the flat tree (possibly a no-op) and dt_ops.ft_addr()
which retreived the address of the final blob.  Since they were only
ever called together, this patch combines the two into a single new
callback, dt_ops.finalize().  This new callback does whatever
platform-dependent things are necessary to produce a final flat device
tree blob, and returns the blob's addres.

Second, the current logic calls the kernel with a flat device tree if
one is build into the zImage wrapper, otherwise it boots the kernel
with a PROM pointer, expecting the kernel to copy the OF device tree
itself.  This approach precludes the possibility of the platform
wrapper code building a flat device tree from whatever
platform-specific information firmware provides.  Thus, this patch
takes the more sensible approach of invoking the kernel with a flat
tree if the dt_ops.finalize callback provides one (by whatever means).

So, the dt_ops.finalize callback can be NULL, or can be a function
which returns NULL.  In either case, the zImage wrapper logic assumes
that this is a platform with OF and invokes the kernel accordingly.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-12-04 20:39:34 +11:00

354 lines
9.5 KiB
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 "zlib.h"
#include "ops.h"
#include "flatdevtree.h"
extern void flush_cache(void *, unsigned long);
extern char _start[];
extern char __bss_start[];
extern char _end[];
extern char _vmlinux_start[];
extern char _vmlinux_end[];
extern char _initrd_start[];
extern char _initrd_end[];
extern char _dtb_start[];
extern char _dtb_end[];
struct addr_range {
unsigned long addr;
unsigned long size;
unsigned long memsize;
};
static struct addr_range vmlinux;
static struct addr_range vmlinuz;
static struct addr_range initrd;
static unsigned long elfoffset;
static int is_64bit;
/* scratch space for gunzip; 46912 is from zlib_inflate_workspacesize() */
static char scratch[46912];
static char elfheader[256];
typedef void (*kernel_entry_t)(unsigned long, unsigned long, void *);
#undef DEBUG
#define HEAD_CRC 2
#define EXTRA_FIELD 4
#define ORIG_NAME 8
#define COMMENT 0x10
#define RESERVED 0xe0
static void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
{
z_stream s;
int r, i, flags;
/* skip header */
i = 10;
flags = src[3];
if (src[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
printf("bad gzipped data\n\r");
exit();
}
if ((flags & EXTRA_FIELD) != 0)
i = 12 + src[10] + (src[11] << 8);
if ((flags & ORIG_NAME) != 0)
while (src[i++] != 0)
;
if ((flags & COMMENT) != 0)
while (src[i++] != 0)
;
if ((flags & HEAD_CRC) != 0)
i += 2;
if (i >= *lenp) {
printf("gunzip: ran out of data in header\n\r");
exit();
}
if (zlib_inflate_workspacesize() > sizeof(scratch)) {
printf("gunzip needs more mem\n");
exit();
}
memset(&s, 0, sizeof(s));
s.workspace = scratch;
r = zlib_inflateInit2(&s, -MAX_WBITS);
if (r != Z_OK) {
printf("inflateInit2 returned %d\n\r", r);
exit();
}
s.next_in = src + i;
s.avail_in = *lenp - i;
s.next_out = dst;
s.avail_out = dstlen;
r = zlib_inflate(&s, Z_FULL_FLUSH);
if (r != Z_OK && r != Z_STREAM_END) {
printf("inflate returned %d msg: %s\n\r", r, s.msg);
exit();
}
*lenp = s.next_out - (unsigned char *) dst;
zlib_inflateEnd(&s);
}
static int is_elf64(void *hdr)
{
Elf64_Ehdr *elf64 = hdr;
Elf64_Phdr *elf64ph;
unsigned int i;
if (!(elf64->e_ident[EI_MAG0] == ELFMAG0 &&
elf64->e_ident[EI_MAG1] == ELFMAG1 &&
elf64->e_ident[EI_MAG2] == ELFMAG2 &&
elf64->e_ident[EI_MAG3] == ELFMAG3 &&
elf64->e_ident[EI_CLASS] == ELFCLASS64 &&
elf64->e_ident[EI_DATA] == ELFDATA2MSB &&
elf64->e_type == ET_EXEC &&
elf64->e_machine == EM_PPC64))
return 0;
elf64ph = (Elf64_Phdr *)((unsigned long)elf64 +
(unsigned long)elf64->e_phoff);
for (i = 0; i < (unsigned int)elf64->e_phnum; i++, elf64ph++)
if (elf64ph->p_type == PT_LOAD)
break;
if (i >= (unsigned int)elf64->e_phnum)
return 0;
elfoffset = (unsigned long)elf64ph->p_offset;
vmlinux.size = (unsigned long)elf64ph->p_filesz + elfoffset;
vmlinux.memsize = (unsigned long)elf64ph->p_memsz + elfoffset;
is_64bit = 1;
return 1;
}
static int is_elf32(void *hdr)
{
Elf32_Ehdr *elf32 = hdr;
Elf32_Phdr *elf32ph;
unsigned int i;
if (!(elf32->e_ident[EI_MAG0] == ELFMAG0 &&
elf32->e_ident[EI_MAG1] == ELFMAG1 &&
elf32->e_ident[EI_MAG2] == ELFMAG2 &&
elf32->e_ident[EI_MAG3] == ELFMAG3 &&
elf32->e_ident[EI_CLASS] == ELFCLASS32 &&
elf32->e_ident[EI_DATA] == ELFDATA2MSB &&
elf32->e_type == ET_EXEC &&
elf32->e_machine == EM_PPC))
return 0;
elf32 = (Elf32_Ehdr *)elfheader;
elf32ph = (Elf32_Phdr *) ((unsigned long)elf32 + elf32->e_phoff);
for (i = 0; i < elf32->e_phnum; i++, elf32ph++)
if (elf32ph->p_type == PT_LOAD)
break;
if (i >= elf32->e_phnum)
return 0;
elfoffset = elf32ph->p_offset;
vmlinux.size = elf32ph->p_filesz + elf32ph->p_offset;
vmlinux.memsize = elf32ph->p_memsz + elf32ph->p_offset;
return 1;
}
static void prep_kernel(unsigned long a1, unsigned long a2)
{
int len;
vmlinuz.addr = (unsigned long)_vmlinux_start;
vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
/* gunzip the ELF header of the kernel */
if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
len = vmlinuz.size;
gunzip(elfheader, sizeof(elfheader),
(unsigned char *)vmlinuz.addr, &len);
} else
memcpy(elfheader, (const void *)vmlinuz.addr,
sizeof(elfheader));
if (!is_elf64(elfheader) && !is_elf32(elfheader)) {
printf("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
exit();
}
if (platform_ops.image_hdr)
platform_ops.image_hdr(elfheader);
/* We need to alloc the memsize plus the file offset since gzip
* will expand the header (file offset), then the kernel, 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", vmlinux.memsize);
vmlinux.addr = (unsigned long)malloc(vmlinux.memsize);
if (vmlinux.addr == 0) {
printf("Can't allocate memory for kernel image !\n\r");
exit();
}
/*
* Now find the initrd
*
* First see if we have an image attached to us. If so
* allocate memory for it and copy it there.
*/
initrd.size = (unsigned long)(_initrd_end - _initrd_start);
initrd.memsize = initrd.size;
if (initrd.size > 0) {
printf("Allocating 0x%lx bytes for initrd ...\n\r",
initrd.size);
initrd.addr = (unsigned long)malloc((u32)initrd.size);
if (initrd.addr == 0) {
printf("Can't allocate memory for initial "
"ramdisk !\n\r");
exit();
}
printf("initial ramdisk moving 0x%lx <- 0x%lx "
"(0x%lx bytes)\n\r", initrd.addr,
(unsigned long)_initrd_start, initrd.size);
memmove((void *)initrd.addr, (void *)_initrd_start,
initrd.size);
printf("initrd head: 0x%lx\n\r",
*((unsigned long *)initrd.addr));
} else if (a2 != 0) {
/* Otherwise, see if yaboot or another loader gave us an initrd */
initrd.addr = a1;
initrd.memsize = initrd.size = a2;
printf("Using loader supplied initrd at 0x%lx (0x%lx bytes)\n\r",
initrd.addr, initrd.size);
}
/* Eventually gunzip the kernel */
if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
len = vmlinuz.size;
gunzip((void *)vmlinux.addr, vmlinux.memsize,
(unsigned char *)vmlinuz.addr, &len);
printf("done 0x%lx bytes\n\r", len);
} else {
memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,
vmlinuz.size);
}
/* Skip over the ELF header */
#ifdef DEBUG
printf("... skipping 0x%lx bytes of ELF header\n\r",
elfoffset);
#endif
vmlinux.addr += elfoffset;
flush_cache((void *)vmlinux.addr, vmlinux.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 builtin_cmdline[COMMAND_LINE_SIZE]
__attribute__((__section__("__builtin_cmdline")));
static void get_cmdline(char *buf, int size)
{
void *devp;
int len = strlen(builtin_cmdline);
buf[0] = '\0';
if (len > 0) { /* builtin_cmdline overrides dt's /chosen/bootargs */
len = min(len, size-1);
strncpy(buf, builtin_cmdline, len);
buf[len] = '\0';
}
else if ((devp = finddevice("/chosen")))
getprop(devp, "bootargs", buf, size);
}
static void set_cmdline(char *buf)
{
void *devp;
if ((devp = finddevice("/chosen")))
setprop(devp, "bootargs", buf, strlen(buf) + 1);
}
struct platform_ops platform_ops;
struct dt_ops dt_ops;
struct console_ops console_ops;
void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
{
kernel_entry_t kentry;
char cmdline[COMMAND_LINE_SIZE];
unsigned long ft_addr = 0;
memset(__bss_start, 0, _end - __bss_start);
memset(&platform_ops, 0, sizeof(platform_ops));
memset(&dt_ops, 0, sizeof(dt_ops));
memset(&console_ops, 0, sizeof(console_ops));
if (platform_init(promptr, _dtb_start, _dtb_end))
exit();
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, sp);
prep_kernel(a1, a2);
/* If cmdline came from zimage wrapper or if we can edit the one
* in the dt, print it out and edit it, if possible.
*/
if ((strlen(builtin_cmdline) > 0) || console_ops.edit_cmdline) {
get_cmdline(cmdline, COMMAND_LINE_SIZE);
printf("\n\rLinux/PowerPC load: %s", cmdline);
if (console_ops.edit_cmdline)
console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
printf("\n\r");
set_cmdline(cmdline);
}
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", promptr);
if (console_ops.close)
console_ops.close();
kentry = (kernel_entry_t) vmlinux.addr;
if (ft_addr)
kentry(ft_addr, 0, NULL);
else
/* XXX initrd addr/size should be passed in properties */
kentry(initrd.addr, initrd.size, promptr);
/* console closed so printf below may not work */
printf("Error: Linux kernel returned to zImage boot wrapper!\n\r");
exit();
}