On Friday 23 June 2017 02:25 PM, Hoeun Ryu wrote:
Arm linux supports zImage with appended dtb (CONFIG_ARM_APPENDED_DTB) and
the concatenated image is generated like `cat zImage dtb > zImage_w_dtb`.
This patch is to support the concatednated zImage. This changes the
priority of source of dtb file.
1. --dtb dtb_file
2. zImage_w_dtb <= newly added
3. /sys/firmware/fdt
4. /proc/device-tree
Users don't need to specify dtb file in the command line and don't have to
have /sys/firmware/fdt or /proc/device-tree if dtb is available in zImage.
any specific reason to not to add the new method as last preferred option?
Does it not work if there exist a /sys/firmware/fdt in case of a kernel booted
with "dtb appended zImage"?
Signed-off-by: Hoeun Ryu <hoeun....@gmail.com>
---
kexec/arch/arm/kexec-arm.h | 1 +
kexec/arch/arm/kexec-zImage-arm.c | 47 ++++++++++++++++++++++++++++++---------
2 files changed, 37 insertions(+), 11 deletions(-)
diff --git a/kexec/arch/arm/kexec-arm.h b/kexec/arch/arm/kexec-arm.h
index a74cce2..94695b7 100644
--- a/kexec/arch/arm/kexec-arm.h
+++ b/kexec/arch/arm/kexec-arm.h
@@ -4,6 +4,7 @@
#include <sys/types.h>
#define SYSFS_FDT "/sys/firmware/fdt"
+#define APPENDED_FDT ((char *)-1) /* it doesn't mean to be opened. */
#define BOOT_BLOCK_VERSION 17
#define BOOT_BLOCK_LAST_COMP_VERSION 16
diff --git a/kexec/arch/arm/kexec-zImage-arm.c
b/kexec/arch/arm/kexec-zImage-arm.c
index 7f02b93..59f0003 100644
--- a/kexec/arch/arm/kexec-zImage-arm.c
+++ b/kexec/arch/arm/kexec-zImage-arm.c
@@ -390,6 +390,7 @@ int zImage_arm_load(int argc, char **argv, const char *buf,
off_t len,
initrd_size = 0;
use_atags = 0;
dtb_file = NULL;
+ dtb_buf = NULL;
while((opt = getopt_long(argc, argv, short_options, options, 0)) != -1)
{
switch(opt) {
default:
@@ -424,14 +425,6 @@ int zImage_arm_load(int argc, char **argv, const char
*buf, off_t len,
return -1;
}
- if (!use_atags && !dtb_file) {
- int f;
-
- f = have_sysfs_fdt();
- if (f)
- dtb_file = SYSFS_FDT;
- }
-
if (command_line) {
command_line_len = strlen(command_line) + 1;
if (command_line_len > COMMAND_LINE_SIZE)
@@ -440,9 +433,6 @@ int zImage_arm_load(int argc, char **argv, const char *buf,
off_t len,
if (ramdisk)
ramdisk_buf = slurp_file(ramdisk, &initrd_size);
- if (dtb_file)
- dtb_buf = slurp_file(dtb_file, &dtb_length);
-
if (len > 0x34) {
const struct zimage_header *hdr;
off_t size;
@@ -459,6 +449,25 @@ int zImage_arm_load(int argc, char **argv, const char
*buf, off_t len,
(unsigned long long)size,
(unsigned long long)len);
+ /* check if zImage has an appended dtb */
+ if (!dtb_file) {
+ if (fdt_check_header(buf + size) == 0) {
What if size >= len? I think, in that case there might not be a valid address
at buf+size and reading those area would lead in segmentation fault.
+ /*
+ * dtb_file won't be opened. It's set
+ * just to pass NULL checking.
+ */
+ dtb_file = APPENDED_FDT;
+ dtb_length = fdt_totalsize(buf + size);
+ dtb_buf = xmalloc(dtb_length);
+ memcpy(dtb_buf, buf+size, dtb_length);
+
+ dbgprintf("found appended dtb, size
0x%llx\n",
+ (unsigned long
long)dtb_length);
+
+
+ }
+ }
+
if (size > len) {
fprintf(stderr,
"zImage is truncated - file 0x%llx vs header
0x%llx\n",
@@ -575,6 +584,22 @@ int zImage_arm_load(int argc, char **argv, const char
*buf, off_t len,
initrd_base = kernel_base + _ALIGN(len * 5, getpagesize());
}
+ if (!use_atags && !dtb_file) {
+ int f;
+
+ f = have_sysfs_fdt();
+ if (f)
+ dtb_file = SYSFS_FDT;
+ }
+
+ /*
+ * dtb_buf can be allocated when checking zImage_with_dtb.
+ * dtb_buf won't be allocated in the logic if dtb_file is handed over
+ * in argv[].
+ */
+ if (dtb_file && !dtb_buf)
+ dtb_buf = slurp_file(dtb_file, &dtb_length);
+
if (use_atags) {
/*
* use ATAGs from /proc/atags
--
Pratyush
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