linux/arch/powerpc/boot/main.c
Oliver O'Halloran a1ff57416a powerpc/boot: Fix the early OPAL console wrappers
When configured with CONFIG_PPC_EARLY_DEBUG_OPAL=y the kernel expects
the OPAL entry and base addresses to be passed in r8 and r9
respectively. Currently the wrapper does not attempt to restore these
values before entering the decompressed kernel which causes the kernel
to branch into whatever happens to be in r9 when doing a write to the
OPAL console in early boot.

This patch adds a platform_ops hook that can be used to branch into the
new kernel. The OPAL console driver patches this at runtime so that if
the console is used it will be restored just prior to entering the
kernel.

Fixes: 656ad58ef1 ("powerpc/boot: Add OPAL console to epapr wrappers")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-24 17:34:01 +11:00

248 lines
7.3 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 "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");
}