linux/arch/x86/purgatory/purgatory.c
Tobin C. Harding e98fe5127b x86/purgatory: Fix sparse warning, symbol not declared
Sparse emits warning, 'symbol not declared' for a function that has
neither file scope nor a forward declaration. The functions only call
site is an ASM file.

Add a header file with the function declaration. Include the header file in
the C source file defining the function in order to fix the sparse
warning. Include the header file in ASM file containing the call site to
document the usage.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Link: http://lkml.kernel.org/r/1487545956-2547-3-git-send-email-me@tobin.cc
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-01 11:27:26 +01:00

74 lines
1.4 KiB
C

/*
* purgatory: Runs between two kernels
*
* Copyright (C) 2014 Red Hat Inc.
*
* Author:
* Vivek Goyal <vgoyal@redhat.com>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include "sha256.h"
#include "purgatory.h"
#include "../boot/string.h"
struct sha_region {
unsigned long start;
unsigned long len;
};
static unsigned long backup_dest;
static unsigned long backup_src;
static unsigned long backup_sz;
static u8 sha256_digest[SHA256_DIGEST_SIZE] = { 0 };
struct sha_region sha_regions[16] = {};
/*
* On x86, second kernel requries first 640K of memory to boot. Copy
* first 640K to a backup region in reserved memory range so that second
* kernel can use first 640K.
*/
static int copy_backup_region(void)
{
if (backup_dest)
memcpy((void *)backup_dest, (void *)backup_src, backup_sz);
return 0;
}
static int verify_sha256_digest(void)
{
struct sha_region *ptr, *end;
u8 digest[SHA256_DIGEST_SIZE];
struct sha256_state sctx;
sha256_init(&sctx);
end = &sha_regions[sizeof(sha_regions)/sizeof(sha_regions[0])];
for (ptr = sha_regions; ptr < end; ptr++)
sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len);
sha256_final(&sctx, digest);
if (memcmp(digest, sha256_digest, sizeof(digest)))
return 1;
return 0;
}
void purgatory(void)
{
int ret;
ret = verify_sha256_digest();
if (ret) {
/* loop forever */
for (;;)
;
}
copy_backup_region();
}