[PATCH 7/7] ARM: Add device tree support to the ARM platform
Matthew Leach
matthew.leach at arm.com
Fri Sep 7 05:11:26 EDT 2012
To allow newer ARM platforms to use kexec, pass device tree
information to the kernel during boot.
By default the dtb is found from /proc/device-tree. A user can specify
a dtb file or use legacy ATAGs
Signed-off-by: Matthew Leach <matthew.leach at arm.com>
---
kexec/arch/arm/Makefile | 13 ++++++
kexec/arch/arm/include/arch/options.h | 6 ++-
kexec/arch/arm/kexec-arm.h | 7 +++
kexec/arch/arm/kexec-zImage-arm.c | 87 +++++++++++++++++++++++++++++++----
4 files changed, 103 insertions(+), 10 deletions(-)
diff --git a/kexec/arch/arm/Makefile b/kexec/arch/arm/Makefile
index 288ec33..192e6ec 100644
--- a/kexec/arch/arm/Makefile
+++ b/kexec/arch/arm/Makefile
@@ -1,11 +1,24 @@
#
# kexec arm (linux booting linux)
#
+include $(srcdir)/kexec/libfdt/Makefile.libfdt
+
+arm_FS2DT = kexec/fs2dt.c
+arm_FS2DT_INCLUDE = -include kexec/arch/arm/crashdump-arm.h \
+ -include kexec/arch/arm/kexec-arm.h
+
arm_KEXEC_SRCS= kexec/arch/arm/kexec-elf-rel-arm.c
arm_KEXEC_SRCS+= kexec/arch/arm/kexec-zImage-arm.c
arm_KEXEC_SRCS+= kexec/arch/arm/kexec-uImage-arm.c
arm_KEXEC_SRCS+= kexec/arch/arm/kexec-arm.c
arm_KEXEC_SRCS+= kexec/arch/arm/crashdump-arm.c
+arm_KEXEC_SRCS+= kexec/fs2dt.c
+
+libfdt_SRCS += $(LIBFDT_SRCS:%=kexec/libfdt/%)
+
+CPPFLAGS+=-I$(srcdir)/kexec/libfdt
+
+arm_KEXEC_SRCS += $(libfdt_SRCS)
arm_UIMAGE = kexec/kexec-uImage.c
arm_PHYS_TO_VIRT = kexec/arch/arm/phys_to_virt.c
diff --git a/kexec/arch/arm/include/arch/options.h b/kexec/arch/arm/include/arch/options.h
index d89c91f..b355c26 100644
--- a/kexec/arch/arm/include/arch/options.h
+++ b/kexec/arch/arm/include/arch/options.h
@@ -5,6 +5,8 @@
#define OPT_APPEND 'a'
#define OPT_RAMDISK 'r'
+#define OPT_DTB (OPT_ARCH_MAX+0)
+#define OPT_ATAGS (OPT_ARCH_MAX+1)
/* Options relevant to the architecture (excluding loader-specific ones),
* in this case none:
@@ -33,7 +35,9 @@
{ "command-line", 1, 0, OPT_APPEND }, \
{ "append", 1, 0, OPT_APPEND }, \
{ "initrd", 1, 0, OPT_RAMDISK }, \
- { "ramdisk", 1, 0, OPT_RAMDISK },
+ { "ramdisk", 1, 0, OPT_RAMDISK }, \
+ { "dtb", 1, 0, OPT_DTB }, \
+ { "atags", 0, 0, OPT_ATAGS },
#define KEXEC_ALL_OPT_STR KEXEC_ARCH_OPT_STR "a:r:"
diff --git a/kexec/arch/arm/kexec-arm.h b/kexec/arch/arm/kexec-arm.h
index 0d9a066..79663e3 100644
--- a/kexec/arch/arm/kexec-arm.h
+++ b/kexec/arch/arm/kexec-arm.h
@@ -1,6 +1,13 @@
#ifndef KEXEC_ARM_H
#define KEXEC_ARM_H
+#include <sys/types.h>
+
+#define BOOT_BLOCK_VERSION 17
+#define BOOT_BLOCK_LAST_COMP_VERSION 16
+
+extern off_t initrd_base, initrd_size;
+
int zImage_arm_probe(const char *buf, off_t len);
int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
struct kexec_info *info);
diff --git a/kexec/arch/arm/kexec-zImage-arm.c b/kexec/arch/arm/kexec-zImage-arm.c
index 88a6c29..46cedbf 100644
--- a/kexec/arch/arm/kexec-zImage-arm.c
+++ b/kexec/arch/arm/kexec-zImage-arm.c
@@ -13,13 +13,18 @@
#include <unistd.h>
#include <getopt.h>
#include <unistd.h>
+#include <libfdt.h>
#include <arch/options.h>
#include "../../kexec.h"
#include "../../kexec-syscall.h"
+#include "kexec-arm.h"
+#include "../../fs2dt.h"
#include "crashdump-arm.h"
#define BOOT_PARAMS_SIZE 1536
+off_t initrd_base = 0, initrd_size = 0;
+
struct tag_header {
uint32_t size;
uint32_t tag;
@@ -96,6 +101,8 @@ void zImage_arm_usage(void)
" --append=STRING Set the kernel command line to STRING.\n"
" --initrd=FILE Use FILE as the kernel's initial ramdisk.\n"
" --ramdisk=FILE Use FILE as the kernel's initial ramdisk.\n"
+ " --dtb=FILE Use FILE as the fdt blob.\n"
+ " --atags Use ATAGs instead of device-tree.\n"
);
}
@@ -219,9 +226,13 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
off_t command_line_len;
const char *ramdisk;
char *ramdisk_buf;
- off_t ramdisk_length;
- off_t ramdisk_offset;
int opt;
+ int use_atags;
+ char *dtb_buf;
+ off_t dtb_length;
+ char *dtb_file;
+ off_t dtb_offset;
+
/* See options.h -- add any more there, too. */
static const struct option options[] = {
KEXEC_ARCH_OPTIONS
@@ -229,6 +240,8 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
{ "append", 1, 0, OPT_APPEND },
{ "initrd", 1, 0, OPT_RAMDISK },
{ "ramdisk", 1, 0, OPT_RAMDISK },
+ { "dtb", 1, 0, OPT_DTB },
+ { "atags", 0, 0, OPT_ATAGS },
{ 0, 0, 0, 0 },
};
static const char short_options[] = KEXEC_ARCH_OPT_STR "a:r:";
@@ -240,7 +253,9 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
command_line_len = 0;
ramdisk = 0;
ramdisk_buf = 0;
- ramdisk_length = 0;
+ initrd_size = 0;
+ use_atags = 0;
+ dtb_file = NULL;
while((opt = getopt_long(argc, argv, short_options, options, 0)) != -1) {
switch(opt) {
default:
@@ -257,15 +272,28 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
case OPT_RAMDISK:
ramdisk = optarg;
break;
+ case OPT_DTB:
+ dtb_file = optarg;
+ break;
+ case OPT_ATAGS:
+ use_atags = 1;
+ break;
}
}
+
+ if (use_atags && dtb_file) {
+ fprintf(stderr, "You can only use ATAGs if you don't specify a "
+ "dtb file.\n");
+ return -1;
+ }
+
if (command_line) {
command_line_len = strlen(command_line) + 1;
if (command_line_len > COMMAND_LINE_SIZE)
command_line_len = COMMAND_LINE_SIZE;
}
if (ramdisk) {
- ramdisk_buf = slurp_file(ramdisk, &ramdisk_length);
+ ramdisk_buf = slurp_file(ramdisk, &initrd_size);
}
/*
@@ -315,12 +343,53 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
/* assume the maximum kernel compression ratio is 4,
* and just to be safe, place ramdisk after that
*/
- ramdisk_offset = base + len * 4;
+ initrd_base = base + len * 4;
- if (atag_arm_load(info, base + atag_offset,
- command_line, command_line_len,
- ramdisk_buf, ramdisk_length, ramdisk_offset) == -1)
- return -1;
+ if (use_atags) {
+ /*
+ * use ATAGs from /proc/atags
+ */
+ if (atag_arm_load(info, base + atag_offset,
+ command_line, command_line_len,
+ ramdisk_buf, initrd_size, initrd_base) == -1)
+ return -1;
+ } else {
+ /*
+ * Read a user-specified DTB file.
+ */
+ if (dtb_file) {
+ dtb_buf = slurp_file(dtb_file, &dtb_length);
+ } else {
+ /*
+ * Extract the DTB from /proc/device-tree.
+ */
+ create_flatten_tree(&dtb_buf, &dtb_length, command_line);
+ }
+
+ if (fdt_check_header(dtb_buf) != 0) {
+ fprintf(stderr, "Invalid FDT buffer.\n");
+ return -1;
+ }
+
+ if (base + atag_offset + dtb_length > base + offset) {
+ fprintf(stderr, "DTB too large!\n");
+ return -1;
+ }
+
+ if (ramdisk) {
+ add_segment(info, ramdisk_buf, initrd_size,
+ initrd_base, initrd_size);
+ }
+
+ /* Stick the dtb at the end of the initrd and page
+ * align it.
+ */
+ dtb_offset = initrd_base + initrd_size + getpagesize();
+ dtb_offset &= ~(getpagesize() - 1);
+
+ add_segment(info, dtb_buf, dtb_length,
+ dtb_offset, dtb_length);
+ }
add_segment(info, buf, len, base + offset, len);
--
1.7.12
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