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 | 10 +++
kexec/arch/arm/include/arch/options.h | 6 +-
kexec/arch/arm/kexec-zImage-arm.c | 140 ++++++++++++++++++++++++++++++++--
3 files changed, 150 insertions(+), 6 deletions(-)
diff --git a/kexec/arch/arm/Makefile b/kexec/arch/arm/Makefile
index 288ec33..f25ce15 100644
--- a/kexec/arch/arm/Makefile
+++ b/kexec/arch/arm/Makefile
@@ -1,12 +1,22 @@
#
# kexec arm (linux booting linux)
#
+include $(srcdir)/util_lib/dtc/Makefile.dtc
+
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
+libfdt_SRCS += $(LIBFDT_SRCS:%=util_lib/libfdt/%)
+dtc_SRCS += $(DTC_SRCS:%=util_lib/dtc/%)
+
+arm_KEXEC_SRCS+= $(libfdt_SRCS)
+arm_KEXEC_SRCS+= $(dtc_SRCS)
+
+CPPFLAGS+=-I$(srcdir)/util_lib/libfdt
+
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-zImage-arm.c b/kexec/arch/arm/kexec-zImage-arm.c
index 88a6c29..74028b8 100644
--- a/kexec/arch/arm/kexec-zImage-arm.c
+++ b/kexec/arch/arm/kexec-zImage-arm.c
@@ -13,6 +13,8 @@
#include <unistd.h>
#include <getopt.h>
#include <unistd.h>
+#include <dtc.h>
+#include <libfdt.h>
#include <arch/options.h>
#include "../../kexec.h"
#include "../../kexec-syscall.h"
@@ -96,6 +98,8 @@ 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"
);
}
@@ -208,6 +212,63 @@ int atag_arm_load(struct kexec_info *info, unsigned long base,
return 0;
}
+void dtb_fixup_chosen_node(char **dtb_buf, off_t *buf_sz, const char *command_line,
+ unsigned long initrd_start, unsigned long initrd_end)
+{
+ if (command_line || initrd_start != initrd_end) {
+ int chosen_offset;
+ int root_offset;
+ int command_line_len = strlen(command_line);
+ off_t new_buf_sz = *buf_sz + command_line_len + 0x50; /* extra space for new node */
+ void *new_buf = malloc(new_buf_sz);
+
+ fdt_open_into(*dtb_buf, new_buf, new_buf_sz);
+
+ root_offset = fdt_path_offset(new_buf, "/");
+ chosen_offset = fdt_path_offset(new_buf, "/chosen");
+ if (chosen_offset == -FDT_ERR_NOTFOUND) {
+ chosen_offset = fdt_add_subnode(new_buf, root_offset, "chosen");
+ }
+ if (chosen_offset < 0) {
+ fprintf(stderr, "Warning: failed to find the chosen node, a specified command line and"
+ " initrd will not be set.\n");
+ free(new_buf);
+ return;
+ }
+
+ /*
+ * Add the 'bootargs' proerpty to the chosen node if the command
+ * line is specified.
+ */
+ if (command_line) {
+ if (fdt_setprop_string(new_buf, chosen_offset,
+ "bootargs", command_line) < 0) {
+ fprintf(stderr, "Warning: failed to set the command line.\n");
+ free(new_buf);
+ return;
+ }
+ }
+
+ /*
+ * Add the 'initrd-start' and 'initrd-end' properties to the
+ * chosen node if an initrd is specified.
+ */
+ if (initrd_start != initrd_end) {
+ if ((fdt_setprop_cell(new_buf, chosen_offset,
+ "initrd-start", initrd_start) < 0) ||
+ (fdt_setprop_cell(new_buf, chosen_offset,
+ "initrd-end", initrd_end) < 0)) {
+ fprintf(stderr, "Warning: failed to set the initrd addresses.\n");
+ return;
+ }
+ }
+
+ free(*dtb_buf);
+ *dtb_buf = new_buf;
+ *buf_sz = new_buf_sz;
+ }
+}
+
int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
struct kexec_info *info)
{
@@ -222,6 +283,12 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
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 +296,8 @@ 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:";
@@ -241,6 +310,8 @@ int zImage_arm_load(int argc, char **argv, const char *buf, off_t len,
ramdisk = 0;
ramdisk_buf = 0;
ramdisk_length = 0;
+ use_atags = 0;
+ dtb_file = NULL;
while((opt = getopt_long(argc, argv, short_options, options, 0)) != -1) {
switch(opt) {
default:
@@ -257,8 +328,21 @@ 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)
@@ -315,12 +399,58 @@ 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;
+ ramdisk_offset = 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, ramdisk_length, ramdisk_offset) == -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.
+ */
+ struct boot_info *bi;
+ bi = dt_from_fs("/proc/device-tree");
+ dtb_buf = dt_to_blob_buf(&dtb_length, bi, DEFAULT_FDT_VERSION);
+ }
+
+ dtb_fixup_chosen_node(&dtb_buf, &dtb_length, command_line,
+ ramdisk_offset, ramdisk_offset + ramdisk_length);
+
+ 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, ramdisk_length,
+ ramdisk_offset, ramdisk_length);
+ }
+
+ /* Stick the dtb at the end of the initrd and page
+ * align it.
+ */
+ dtb_offset = ramdisk_offset + ramdisk_length + 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
