aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorH. Peter Anvin <hpa@linux.intel.com>2009-04-03 16:09:29 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2009-04-03 16:09:29 -0700
commitddad35c72c939a87ee840cde7522cd7ef907b6b5 (patch)
tree7bfc83064edbcc8cd25ffeaebf44fe017d60763f
parent5a18a8a0def0ac8ced4f10d8f93a7b737339c8fc (diff)
downloadsyslinux.git-ddad35c72c939a87ee840cde7522cd7ef907b6b5.tar.gz
syslinux.git-ddad35c72c939a87ee840cde7522cd7ef907b6b5.tar.xz
syslinux.git-ddad35c72c939a87ee840cde7522cd7ef907b6b5.zip
linux.c32: make load_linux() support relocation
In the case where the preferred kernel locations are not available, make load_linux() smart enough to be able to relocate the kernel if at all possible. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
-rw-r--r--com32/include/syslinux/align.h47
-rw-r--r--com32/lib/sys/argv.c7
-rw-r--r--com32/lib/syslinux/load_linux.c78
3 files changed, 128 insertions, 4 deletions
diff --git a/com32/include/syslinux/align.h b/com32/include/syslinux/align.h
new file mode 100644
index 00000000..5b01bf27
--- /dev/null
+++ b/com32/include/syslinux/align.h
@@ -0,0 +1,47 @@
+/* ----------------------------------------------------------------------- *
+ *
+ * Copyright 2009 Intel Corporation; author H. Peter Anvin
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall
+ * be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ----------------------------------------------------------------------- */
+
+#ifndef _SYSLINUX_ALIGN_H
+#define _SYSLINUX_ALIGN_H
+
+#include <stdint.h>
+
+static inline uintptr_t __align_down(uintptr_t __p, uintptr_t __a)
+{
+ return __p & ~(__a - 1);
+}
+static inline uintptr_t __align_up(uintptr_t __p, uintptr_t __a)
+{
+ return (__p + __a - 1) & ~(__a - 1);
+}
+
+#define ALIGN_UP(p,a) ((__typeof__(p))__align_up((uintptr_t)(p), (a)))
+#define ALIGN_DOWN(p,a) ((__typeof__(p))__align_down((uintptr_t)(p), (a)))
+#define ALIGN_UP_FOR(p,t) ALIGN_UP(p,sizeof(t))
+#define ALIGN_DOWN_FOR(p,t) ALIGN_DOWN(p,sizeof(t))
+
+#endif /* _SYSLINUX_ALIGN_H */
diff --git a/com32/lib/sys/argv.c b/com32/lib/sys/argv.c
index 0d16bfe6..8b55d940 100644
--- a/com32/lib/sys/argv.c
+++ b/com32/lib/sys/argv.c
@@ -1,6 +1,6 @@
/* ----------------------------------------------------------------------- *
*
- * Copyright 2004-2008 H. Peter Anvin - All Rights Reserved
+ * Copyright 2004-2009 H. Peter Anvin - All Rights Reserved
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
@@ -35,8 +35,7 @@
#include <inttypes.h>
#include <stddef.h>
#include <stdio.h>
-
-#define ALIGN_UP(p,t) ((t *)(((uintptr_t)(p) + (sizeof(t)-1)) & ~(sizeof(t)-1)))
+#include <syslinux/align.h>
extern char _end[]; /* Symbol created by linker */
void *__mem_end = &_end; /* Global variable for use by malloc() */
@@ -75,7 +74,7 @@ int __parse_argv(char ***argv, const char *str)
}
/* Now create argv */
- arg = ALIGN_UP(q,char *);
+ arg = ALIGN_UP_FOR(q, char *);
*argv = arg;
*arg++ = argv0; /* argv[0] */
diff --git a/com32/lib/syslinux/load_linux.c b/com32/lib/syslinux/load_linux.c
index cca2efd0..4f583cd7 100644
--- a/com32/lib/syslinux/load_linux.c
+++ b/com32/lib/syslinux/load_linux.c
@@ -31,9 +31,11 @@
* Load a Linux kernel (Image/zImage/bzImage).
*/
+#include <stdbool.h>
#include <stdlib.h>
#include <inttypes.h>
#include <string.h>
+#include <syslinux/align.h>
#include <syslinux/linux.h>
#include <syslinux/bootrm.h>
#include <syslinux/movebits.h>
@@ -159,6 +161,7 @@ int syslinux_boot_linux(void *kernel_buf, size_t kernel_size,
struct syslinux_movelist *fraglist = NULL;
struct syslinux_memmap *mmap = NULL;
struct syslinux_memmap *amap = NULL;
+ bool ok;
cmdline_size = strlen(cmdline)+1;
@@ -189,6 +192,9 @@ int syslinux_boot_linux(void *kernel_buf, size_t kernel_size,
if (!memlimit || memlimit-1 > hdr.initrd_addr_max)
memlimit = hdr.initrd_addr_max+1; /* Zero for no limit */
+ if (hdr.version < 0x0205)
+ hdr.relocatable_kernel = 0;
+
if (hdr.version < 0x0206)
hdr.cmdline_max_len = 256;
@@ -250,7 +256,79 @@ int syslinux_boot_linux(void *kernel_buf, size_t kernel_size,
/* Place the kernel in memory */
+ /* First, find a suitable place for the protected-mode code */
+ if (syslinux_memmap_type(amap, prot_mode_base, prot_mode_size)
+ != SMT_FREE) {
+ const struct syslinux_memmap *mp;
+ if (!hdr.relocatable_kernel)
+ goto bail; /* Can't relocate - no hope */
+
+ ok = false;
+ for (mp = amap; mp; mp = mp->next) {
+ addr_t start, end;
+ start = mp->start;
+ end = mp->next->start;
+
+ if (mp->type != SMT_FREE)
+ continue;
+
+ if (end <= prot_mode_base)
+ continue; /* Only relocate upwards */
+
+ if (start <= prot_mode_base)
+ start = prot_mode_base;
+
+ start = ALIGN_UP(start, hdr.kernel_alignment);
+ if (start >= end)
+ continue;
+
+ /* The 3* here is a total fudge factor... it's supposed to
+ account for the fact that the kernel needs to be decompressed,
+ and then followed by the BSS and BRK regions. This doesn't,
+ however, account for the fact that the kernel is decompressed
+ into a whole other place, either. */
+ if (end - start >= 3*prot_mode_size) {
+ prot_mode_base = start;
+ ok = true;
+ break;
+ }
+ }
+
+ if (!ok)
+ goto bail;
+ }
+
/* Real mode code */
+ if (syslinux_memmap_type(amap, real_mode_base,
+ cmdline_offset+cmdline_size) != SMT_FREE) {
+ const struct syslinux_memmap *mp;
+
+ ok = false;
+ for (mp = amap; mp; mp = mp->next) {
+ addr_t start, end;
+ start = mp->start;
+ end = mp->next->start;
+
+ if (mp->type != SMT_FREE)
+ continue;
+
+ if (start < real_mode_base)
+ start = real_mode_base; /* Lowest address we'll use */
+ if (end > 640*1024)
+ end = 640*1024;
+
+ start = ALIGN_UP(start, 16);
+ if (start >= end)
+ continue;
+
+ if (end - start >= cmdline_offset+cmdline_size) {
+ real_mode_base = start;
+ ok = true;
+ break;
+ }
+ }
+ }
+
if (syslinux_add_movelist(&fraglist, real_mode_base, (addr_t)kernel_buf,
real_mode_size))
goto bail;