[PATCH] add support for loading lzma compressed kernels
Florian Fainelli
florian at openwrt.org
Sun Nov 15 18:53:06 EST 2009
Hi Eric,
This patch allows one to load a lzma compressed kernel using kexec -l.
As I wanted the lzma code to be very similar to the existing
zlib slurp_decompress I took lzread and associated routines
from the cpio lzma support. Tested on my x86 laptop using the
following commands:
lzma e bzImage bzImage.lzma
kexec -l bzImage.lzma
Having lzma support is particularly useful on some embedded
systems on which we have the kernel already lzma compressed
and available on a mtd partition.
Signed-off-by: Florian Fainelli <florian at openwrt.org>
--
diff -urN kexec-tools-2.0.1/configure.ac kexec-tools-2.0.1.lzma/configure.ac
--- kexec-tools-2.0.1/configure.ac 2009-08-13 01:28:04.000000000 +0200
+++ kexec-tools-2.0.1.lzma/configure.ac 2009-11-16 00:30:42.000000000 +0100
@@ -79,6 +79,9 @@
AC_ARG_WITH([zlib], AC_HELP_STRING([--without-zlib],[disable zlib support]),
[ with_zlib="$withval"], [ with_zlib=yes ] )
+AC_ARG_WITH([lzma], AC_HELP_STRING([--without-lzma],[disable lzma support]),
+ [ with_lzma="$withval"], [ with_lzma=yes ] )
+
AC_ARG_WITH([xen], AC_HELP_STRING([--without-xen],
[disable extended xen support]), [ with_xen="$withval"], [ with_xen=yes ] )
@@ -142,6 +145,12 @@
AC_MSG_NOTICE([zlib support disabled])))
fi
+dnl See if I have a usable copy of lzma available
+if test "$with_lzma" = yes ; then
+ AC_CHECK_HEADER(lzma.h,
+ AC_CHECK_LIB(lzma, lzma_code_, ,
+ AC_MSG_NOTICE([lzma support disabled])))
+
dnl find Xen control stack libraries
if test "$with_xen" = yes ; then
AC_CHECK_HEADER(xenctrl.h,
diff -urN kexec-tools-2.0.1/include/kexec_lzma.h kexec-tools-2.0.1.lzma/include/kexec_lzma.h
--- kexec-tools-2.0.1/include/kexec_lzma.h 1970-01-01 01:00:00.000000000 +0100
+++ kexec-tools-2.0.1.lzma/include/kexec_lzma.h 2009-11-16 00:45:23.000000000 +0100
@@ -0,0 +1,24 @@
+#ifndef __KEXEC_LZMA_H
+#define __KEXEC_LZMA_H
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <lzma.h>
+
+#define kBufferSize (1 << 15)
+
+typedef struct lzfile {
+ uint8_t buf[kBufferSize];
+ lzma_stream strm;
+ FILE *file;
+ int encoding;
+ int eof;
+} LZFILE;
+
+LZFILE *lzopen(const char *path, const char *mode);
+int lzclose(LZFILE *lzfile);
+ssize_t lzread(LZFILE *lzfile, void *buf, size_t len);
+
+#endif /* __KEXEC_LZMA_H */
Files kexec-tools-2.0.1/kexec/.kexec.c.swo and kexec-tools-2.0.1.lzma/kexec/.kexec.c.swo differ
diff -urN kexec-tools-2.0.1/kexec/Makefile kexec-tools-2.0.1.lzma/kexec/Makefile
--- kexec-tools-2.0.1/kexec/Makefile 2008-10-09 00:32:14.000000000 +0200
+++ kexec-tools-2.0.1.lzma/kexec/Makefile 2009-11-15 20:36:37.000000000 +0100
@@ -22,6 +22,7 @@
KEXEC_SRCS += kexec/crashdump.c
KEXEC_SRCS += kexec/crashdump-xen.c
KEXEC_SRCS += kexec/phys_arch.c
+KEXEC_SRCS += kexec/lzma.c
KEXEC_GENERATED_SRCS += $(PURGATORY_HEX_C)
diff -urN kexec-tools-2.0.1/kexec/kexec.c kexec-tools-2.0.1.lzma/kexec/kexec.c
--- kexec-tools-2.0.1/kexec/kexec.c 2009-03-18 09:38:55.000000000 +0100
+++ kexec-tools-2.0.1.lzma/kexec/kexec.c 2009-11-16 00:50:37.000000000 +0100
@@ -41,6 +41,9 @@
#ifdef HAVE_LIBZ
#include <zlib.h>
#endif
+#ifdef HAVE_LIBLZMA
+#include <kexec_lzma.h>
+#endif
#include <sha256.h>
#include "kexec.h"
#include "kexec-syscall.h"
@@ -609,6 +612,47 @@
*r_size = size;
return buf;
}
+#elif defined (HAVE_LIBLZMA)
+char *slurp_decompress_file(const char *filename, off_t *r_size)
+{
+ LZFILE *fp;
+ char *buf;
+ off_t size, allocated;
+ ssize_t result;
+
+ if (!filename) {
+ *r_size = 0;
+ return 0;
+ }
+ fp = lzopen(filename, "rb");
+ if (fp == 0) {
+ die("Cannot open `%s': %s\n", filename);
+ }
+ size = 0;
+ allocated = 65536;
+ buf = xmalloc(allocated);
+ do {
+ if (size == allocated) {
+ allocated <<= 1;
+ buf = xrealloc(buf, allocated);
+ }
+ result = lzread(fp, buf + size, allocated - size);
+ if (result < 0) {
+ if ((errno == EINTR) || (errno == EAGAIN))
+ continue;
+
+ die ("read on %s of %ld bytes failed\n",
+ filename, (allocated - size) + 0UL);
+ }
+ size += result;
+ } while(result > 0);
+ result = lzclose(fp);
+ if (result != LZMA_OK) {
+ die ("Close of %s failed\n", filename);
+ }
+ *r_size = size;
+ return buf;
+}
#else
char *slurp_decompress_file(const char *filename, off_t *r_size)
{
diff -urN kexec-tools-2.0.1/kexec/lzma.c kexec-tools-2.0.1.lzma/kexec/lzma.c
--- kexec-tools-2.0.1/kexec/lzma.c 1970-01-01 01:00:00.000000000 +0100
+++ kexec-tools-2.0.1.lzma/kexec/lzma.c 2009-11-16 00:44:56.000000000 +0100
@@ -0,0 +1,132 @@
+#include <sys/types.h>
+#include <inttypes.h>
+#include <string.h>
+#include <stdlib.h>
+#include <lzma.h>
+#include <kexec_lzma.h>
+
+#ifdef HAVE_LIBLZMA
+static LZFILE *lzopen_internal(const char *path, const char *mode, int fd)
+{
+ int level = 5;
+ int encoding = 0;
+ FILE *fp;
+ LZFILE *lzfile;
+ lzma_ret ret;
+ lzma_stream lzma_strm_tmp = LZMA_STREAM_INIT;
+
+ for (; *mode; mode++) {
+ if (*mode == 'w')
+ encoding = 1;
+ else if (*mode == 'r')
+ encoding = 0;
+ else if (*mode >= '1' && *mode <= '9')
+ level = *mode - '0';
+ }
+ if (fd != -1)
+ fp = fdopen(fd, encoding ? "w" : "r");
+ else
+ fp = fopen(path, encoding ? "w" : "r");
+ if (!fp)
+ return NULL;
+
+ lzfile = calloc(1, sizeof(*lzfile));
+
+ if (!lzfile) {
+ fclose(fp);
+ return NULL;
+ }
+
+ lzfile->file = fp;
+ lzfile->encoding = encoding;
+ lzfile->eof = 0;
+ lzfile->strm = lzma_strm_tmp;
+ if (encoding) {
+ lzma_options_lzma opt_lzma;
+ if (lzma_lzma_preset(&opt_lzma, level - 1))
+ return NULL;
+ ret = lzma_alone_encoder(&lzfile->strm, &opt_lzma);
+ } else {
+ ret = lzma_auto_decoder(&lzfile->strm,
+ UINT64_C(64) * 1024 * 1024, 0);
+ }
+ if (ret != LZMA_OK) {
+ fclose(fp);
+ free(lzfile);
+ return NULL;
+ }
+ return lzfile;
+}
+
+LZFILE *lzopen(const char *path, const char *mode)
+{
+ return lzopen_internal(path, mode, -1);
+}
+
+int lzclose(LZFILE *lzfile)
+{
+ lzma_ret ret;
+ int n;
+
+ if (!lzfile)
+ return -1;
+
+ if (lzfile->encoding) {
+ for (;;) {
+ lzfile->strm.avail_out = kBufferSize;
+ lzfile->strm.next_out = lzfile->buf;
+ ret = lzma_code(&lzfile->strm, LZMA_FINISH);
+ if (ret != LZMA_OK && ret != LZMA_STREAM_END)
+ return -1;
+ n = kBufferSize - lzfile->strm.avail_out;
+ if (n && fwrite(lzfile->buf, 1, n, lzfile->file) != n)
+ return -1;
+ if (ret == LZMA_STREAM_END)
+ break;
+ }
+ }
+ lzma_end(&lzfile->strm);
+
+ return fclose(lzfile->file);
+ free(lzfile);
+}
+
+ssize_t lzread(LZFILE *lzfile, void *buf, size_t len)
+{
+ lzma_ret ret;
+ int eof = 0;
+
+ if (!lzfile || lzfile->encoding)
+ return -1;
+
+ if (lzfile->eof)
+ return 0;
+
+ lzfile->strm.next_out = buf;
+ lzfile->strm.avail_out = len;
+
+ for (;;) {
+ if (!lzfile->strm.avail_in) {
+ lzfile->strm.next_in = lzfile->buf;
+ lzfile->strm.avail_in = fread(lzfile->buf, 1, kBufferSize, lzfile->file);
+ if (!lzfile->strm.avail_in)
+ eof = 1;
+ }
+
+ ret = lzma_code(&lzfile->strm, LZMA_RUN);
+ if (ret == LZMA_STREAM_END) {
+ lzfile->eof = 1;
+ return len - lzfile->strm.avail_out;
+ }
+
+ if (ret != LZMA_OK)
+ return -1;
+
+ if (!lzfile->strm.avail_out)
+ return len;
+
+ if (eof)
+ return -1;
+ }
+}
+#endif /* HAVE_LIBLZMA */
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