linux/arch/powerpc/boot/main.c
mostrows@watson.ibm.com 30d8caf7c6 [POWERPC] Editable kernel command-line in zImage binary.
zImage will set /chosen/bootargs (if it is otherwise empty) with the
contents of a buffer in the section "__builtin_cmdline".  This permits
tools to edit zImage binaries to set the command-line eventually
processed by vmlinux.

--
Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-15 19:31:25 +10:00

347 lines
9.1 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 "prom.h"
#include "zlib.h"
extern void flush_cache(void *, unsigned long);
/* Value picked to match that used by yaboot */
#define PROG_START 0x01400000 /* only used on 64-bit systems */
#define RAM_END (512<<20) /* Fixme: use OF */
#define ONE_MB 0x100000
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[];
/* 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[512]
__attribute__((section("__builtin_cmdline")));
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 char scratch[46912]; /* scratch space for gunzip, from zlib_inflate_workspacesize() */
static char elfheader[256];
typedef void (*kernel_entry_t)( unsigned long,
unsigned long,
void *,
void *);
#undef DEBUG
static unsigned long claim_base;
#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 unsigned long try_claim(unsigned long size)
{
unsigned long addr = 0;
for(; claim_base < RAM_END; claim_base += ONE_MB) {
#ifdef DEBUG
printf(" trying: 0x%08lx\n\r", claim_base);
#endif
addr = (unsigned long)claim(claim_base, size, 0);
if ((void *)addr != (void *)-1)
break;
}
if (addr == 0)
return 0;
claim_base = PAGE_ALIGN(claim_base + size);
return addr;
}
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;
#if defined(PROG_START)
/*
* Maintain a "magic" minimum address. This keeps some older
* firmware platforms running.
*/
if (claim_base < PROG_START)
claim_base = PROG_START;
#endif
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;
}
void export_cmdline(void* chosen_handle)
{
int len;
char cmdline[2] = { 0, 0 };
if (builtin_cmdline[0] == 0)
return;
len = getprop(chosen_handle, "bootargs", cmdline, sizeof(cmdline));
if (len > 0 && cmdline[0] != 0)
return;
setprop(chosen_handle, "bootargs", builtin_cmdline,
strlen(builtin_cmdline) + 1);
}
void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
{
int len;
kernel_entry_t kernel_entry;
memset(__bss_start, 0, _end - __bss_start);
prom = (int (*)(void *)) promptr;
chosen_handle = finddevice("/chosen");
if (chosen_handle == (void *) -1)
exit();
if (getprop(chosen_handle, "stdout", &stdout, sizeof(stdout)) != 4)
exit();
printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r", _start, sp);
/*
* The first available claim_base must be above the end of the
* the loaded kernel wrapper file (_start to _end includes the
* initrd image if it is present) and rounded up to a nice
* 1 MB boundary for good measure.
*/
claim_base = _ALIGN_UP((unsigned long)_end, ONE_MB);
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();
}
/* We need to claim 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 = try_claim(vmlinux.memsize);
if (vmlinux.addr == 0) {
printf("Can't allocate memory for kernel image !\n\r");
exit();
}
/*
* Now we try to claim memory for the initrd (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 = try_claim(initrd.size);
if (initrd.addr == 0) {
printf("Can't allocate memory for initial ramdisk !\n\r");
exit();
}
a1 = initrd.addr;
a2 = initrd.size;
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));
}
/* 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);
}
export_cmdline(chosen_handle);
/* 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);
kernel_entry = (kernel_entry_t)vmlinux.addr;
#ifdef DEBUG
printf( "kernel:\n\r"
" entry addr = 0x%lx\n\r"
" a1 = 0x%lx,\n\r"
" a2 = 0x%lx,\n\r"
" prom = 0x%lx,\n\r"
" bi_recs = 0x%lx,\n\r",
(unsigned long)kernel_entry, a1, a2,
(unsigned long)prom, NULL);
#endif
kernel_entry(a1, a2, prom, NULL);
printf("Error: Linux kernel returned to zImage bootloader!\n\r");
exit();
}