From: Dirk Brandewie <[email protected]>
This patch set adds the ability to link device tree blobs into
vmlinux.
Patch 1 implements the changes to include/asm-generic/vmlinux.lds.h and
adds a generic rule for generating DTB objects to be linked vmlinux.
Patch 2 implements linking a DTB into an x86 image.
Patch 3-4 move {powerpc,microblaze}/boot/Makefile to use the dtc rule
in patch 1.
This patch set has been tested on x86.
Powerpc and Microblaze have been compile tested with and without patch
3 and 4 applied.
Changes from V1:
Documentation added for dtc command in Makefile.lib to
Documentation/kbuild/makefiles.txt
Separate DTB_ALIGNMENT define removed.
FORCE removed from dtc rule.
Removed hardcoded path to dts files from dtc command.
Moved %.dtb: %.dts rule to arch specific makefiles.
Patch for adding kernel command line option to pass in dtb_compat
string dropped from this set will be submitted seperately.
Dirk Brandewie (4):
of: Add support for linking device tree blobs into vmlinux
x86/of: Add building device tree blob(s) into image.
of/powerpc: Use generic rule to build dtb's
microblaze/of: Use generic rule to build dtb's
Documentation/kbuild/makefiles.txt | 15 +++++++++++++++
arch/microblaze/boot/Makefile | 10 ++--------
arch/powerpc/boot/Makefile | 8 +++-----
arch/x86/platform/ce4100/Makefile | 10 ++++++++++
include/asm-generic/vmlinux.lds.h | 15 ++++++++++++---
scripts/Makefile.lib | 21 ++++++++++++++++++++-
6 files changed, 62 insertions(+), 17 deletions(-)
--
1.7.2.3
From: Dirk Brandewie <[email protected]>
Modify arch/powerpc/boot/Makefile to use dtc command in
scripts/Makefile.lib
Signed-off-by: Dirk Brandewie <[email protected]>
---
arch/powerpc/boot/Makefile | 8 +++-----
1 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index fae8192..3afb33a 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -35,7 +35,7 @@ endif
BOOTCFLAGS += -I$(obj) -I$(srctree)/$(obj)
-DTS_FLAGS ?= -p 1024
+DTC_FLAGS ?= -p 1024
$(obj)/4xx.o: BOOTCFLAGS += -mcpu=405
$(obj)/ebony.o: BOOTCFLAGS += -mcpu=405
@@ -332,10 +332,8 @@ $(obj)/treeImage.%: vmlinux $(obj)/%.dtb $(wrapperbits)
$(call if_changed,wrap,treeboot-$*,,$(obj)/$*.dtb)
# Rule to build device tree blobs
-DTC = $(objtree)/scripts/dtc/dtc
-
-$(obj)/%.dtb: $(dtstree)/%.dts
- $(DTC) -O dtb -o $(obj)/$*.dtb -b 0 $(DTS_FLAGS) $(dtstree)/$*.dts
+$(obj)/%.dtb: $(src)/dts/%.dts
+ $(call if_changed,dtc)
# If there isn't a platform selected then just strip the vmlinux.
ifeq (,$(image-y))
--
1.7.2.3
From: Dirk Brandewie <[email protected]>
This patch adds support for linking device tree blob(s) into
vmlinux. Modifies asm-generic/vmlinux.lds.h to add linking
.dtb sections into vmlinux. To maintain compatiblity with the of/fdt
driver code platforms MUST copy the blob to a non-init memory location
before the kernel frees the .init.* sections in the image.
Modifies scripts/Makefile.lib to add a kbuild command to
compile DTS files to device tree blobs and a rule to create objects to
wrap the blobs for linking.
STRUCT_ALIGNMENT is defined in vmlinux.lds.h for use in the rule to
create wrapper objects for the dtb in Makefile.lib. The
STRUCT_ALIGN() macro in vmlinux.lds.h is modified to use the
STRUCT_ALIGNMENT definition.
The DTB's are placed on 32 byte boundries to allow parsing the blob
with driver/of/fdt.c during early boot without having to copy the blob
to get the structure alignment GCC expects.
A DTB is linked in by adding the DTB object to the list of objects to
be linked into vmlinux in the archtecture specific Makefile using
obj-y += foo.dtb.o
Signed-off-by: Dirk Brandewie <[email protected]>
---
Documentation/kbuild/makefiles.txt | 15 +++++++++++++++
include/asm-generic/vmlinux.lds.h | 15 ++++++++++++---
scripts/Makefile.lib | 21 ++++++++++++++++++++-
3 files changed, 47 insertions(+), 4 deletions(-)
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index 0ef00bd..fc18bb1 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -1136,6 +1136,21 @@ When kbuild executes, the following steps are followed (roughly):
resulting in the target file being recompiled for no
obvious reason.
+ dtc
+ Create flattend device tree blob object suitable for linking
+ into vmlinux. Device tree blobs linked into vmlinux are placed
+ in an init section in the image. Platform code *must* copy the
+ blob to non-init memory prior to calling unflatten_device_tree().
+
+ Example:
+ #arch/x86/platform/ce4100/Makefile
+ clean-files := *dtb.S
+
+ DTC_FLAGS := -p 1024
+ obj-y += foo.dtb.o
+
+ $(obj)/%.dtb: $(src)/%.dts
+ $(call if_changed,dtc)
--- 6.7 Custom kbuild commands
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index bd69d79..024d3b9 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -23,7 +23,7 @@
* _etext = .;
*
* _sdata = .;
- * RO_DATA_SECTION(PAGE_SIZE)
+* RO_DATA_SECTION(PAGE_SIZE)
* RW_DATA_SECTION(...)
* _edata = .;
*
@@ -67,7 +67,8 @@
* Align to a 32 byte boundary equal to the
* alignment gcc 4.5 uses for a struct
*/
-#define STRUCT_ALIGN() . = ALIGN(32)
+#define STRUCT_ALIGNMENT 32
+#define STRUCT_ALIGN() . = ALIGN(STRUCT_ALIGNMENT)
/* The actual configuration determine if the init/exit sections
* are handled as text/data or they can be discarded (which
@@ -146,6 +147,13 @@
#define TRACE_SYSCALLS()
#endif
+
+#define KERNEL_DTB() \
+ STRUCT_ALIGN(); \
+ VMLINUX_SYMBOL(__dtb_start) = .; \
+ *(.dtb.init.rodata) \
+ VMLINUX_SYMBOL(__dtb_end) = .;
+
/* .data section */
#define DATA_DATA \
*(.data) \
@@ -468,7 +476,8 @@
MCOUNT_REC() \
DEV_DISCARD(init.rodata) \
CPU_DISCARD(init.rodata) \
- MEM_DISCARD(init.rodata)
+ MEM_DISCARD(init.rodata) \
+ KERNEL_DTB()
#define INIT_TEXT \
*(.init.text) \
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 4c72c11..937eabbb 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -200,7 +200,26 @@ quiet_cmd_gzip = GZIP $@
cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -f -9 > $@) || \
(rm -f $@ ; false)
-
+# DTC
+# ---------------------------------------------------------------------------
+
+# Generate an assembly file to wrap the output of the device tree compiler
+$(obj)/%.dtb.S: $(obj)/%.dtb
+ @echo '#include <asm-generic/vmlinux.lds.h>' > $@
+ @echo '.section .dtb.init.rodata,"a"' >> $@
+ @echo '.balign STRUCT_ALIGNMENT' >> $@
+ @echo '.global __dtb_$(*F)_begin' >> $@
+ @echo '__dtb_$(*F)_begin:' >> $@
+ @echo '.incbin "$<" ' >> $@
+ @echo '__dtb_$(*F)_end:' >> $@
+ @echo '.global __dtb_$(*F)_end' >> $@
+ @echo '.balign STRUCT_ALIGNMENT' >> $@
+
+DTC = $(objtree)/scripts/dtc/dtc
+
+quiet_cmd_dtc = DTC $@
+ cmd_dtc = $(DTC) -O dtb -o $@ -b 0 $(DTC_FLAGS) $<
+ooo
# Bzip2
# ---------------------------------------------------------------------------
--
1.7.2.3
From: Dirk Brandewie <[email protected]>
Modify arch/powerpc/boot/Makefile to use dtc command in
scripts/Makefile.lib
Signed-off-by: Dirk Brandewie <[email protected]>
---
arch/microblaze/boot/Makefile | 10 ++--------
1 files changed, 2 insertions(+), 8 deletions(-)
diff --git a/arch/microblaze/boot/Makefile b/arch/microblaze/boot/Makefile
index be01d78..52430e5 100644
--- a/arch/microblaze/boot/Makefile
+++ b/arch/microblaze/boot/Makefile
@@ -10,9 +10,6 @@ targets := linux.bin linux.bin.gz simpleImage.%
OBJCOPYFLAGS := -O binary
-# Where the DTS files live
-dtstree := $(srctree)/$(src)/dts
-
# Ensure system.dtb exists
$(obj)/linked_dtb.o: $(obj)/system.dtb
@@ -51,14 +48,11 @@ $(obj)/simpleImage.%: vmlinux FORCE
$(call if_changed,strip)
@echo 'Kernel: $@ is ready' ' (#'`cat .version`')'
-# Rule to build device tree blobs
-DTC = $(objtree)/scripts/dtc/dtc
# Rule to build device tree blobs
-quiet_cmd_dtc = DTC $@
- cmd_dtc = $(DTC) -O dtb -o $(obj)/$*.dtb -b 0 -p 1024 $(dtstree)/$*.dts
+DTC_FLAGS := -p 1024
-$(obj)/%.dtb: $(dtstree)/%.dts FORCE
+$(obj)/%.dtb: $(src)/dts/%.dts FORCE
$(call if_changed,dtc)
clean-files += *.dtb simpleImage.*.unstrip linux.bin.ub
--
1.7.2.3
From: Dirk Brandewie <[email protected]>
This patch adds linking device tree blob into vmlinux. DTB's are
added by adding the blob object name to list of objects to be linked
into the image.
Signed-off-by: Dirk Brandewie <[email protected]>
---
arch/x86/platform/ce4100/Makefile | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/arch/x86/platform/ce4100/Makefile b/arch/x86/platform/ce4100/Makefile
index 91fc929..3b49187 100644
--- a/arch/x86/platform/ce4100/Makefile
+++ b/arch/x86/platform/ce4100/Makefile
@@ -1 +1,11 @@
obj-$(CONFIG_X86_INTEL_CE) += ce4100.o
+clean-files := *dtb.S
+
+ifdef CONFIG_X86_OF
+###
+# device tree blob
+obj-$(CONFIG_X86_INTEL_CE) += ce4100.dtb.o
+
+$(obj)/%.dtb: $(src)/%.dts
+ $(call if_changed,dtc)
+endif
--
1.7.2.3
On Mon, Dec 06, 2010 at 09:35:59AM -0800, [email protected] wrote:
> From: Dirk Brandewie <[email protected]>
>
> This patch adds support for linking device tree blob(s) into
> vmlinux. Modifies asm-generic/vmlinux.lds.h to add linking
> .dtb sections into vmlinux. To maintain compatiblity with the of/fdt
> driver code platforms MUST copy the blob to a non-init memory location
> before the kernel frees the .init.* sections in the image.
>
> Modifies scripts/Makefile.lib to add a kbuild command to
> compile DTS files to device tree blobs and a rule to create objects to
> wrap the blobs for linking.
>
> STRUCT_ALIGNMENT is defined in vmlinux.lds.h for use in the rule to
> create wrapper objects for the dtb in Makefile.lib. The
> STRUCT_ALIGN() macro in vmlinux.lds.h is modified to use the
> STRUCT_ALIGNMENT definition.
>
> The DTB's are placed on 32 byte boundries to allow parsing the blob
> with driver/of/fdt.c during early boot without having to copy the blob
> to get the structure alignment GCC expects.
>
> A DTB is linked in by adding the DTB object to the list of objects to
> be linked into vmlinux in the archtecture specific Makefile using
> obj-y += foo.dtb.o
>
> Signed-off-by: Dirk Brandewie <[email protected]>
> ---
> Documentation/kbuild/makefiles.txt | 15 +++++++++++++++
> include/asm-generic/vmlinux.lds.h | 15 ++++++++++++---
> scripts/Makefile.lib | 21 ++++++++++++++++++++-
> 3 files changed, 47 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
> index 0ef00bd..fc18bb1 100644
> --- a/Documentation/kbuild/makefiles.txt
> +++ b/Documentation/kbuild/makefiles.txt
> @@ -1136,6 +1136,21 @@ When kbuild executes, the following steps are followed (roughly):
> resulting in the target file being recompiled for no
> obvious reason.
>
> + dtc
> + Create flattend device tree blob object suitable for linking
> + into vmlinux. Device tree blobs linked into vmlinux are placed
> + in an init section in the image. Platform code *must* copy the
> + blob to non-init memory prior to calling unflatten_device_tree().
> +
> + Example:
> + #arch/x86/platform/ce4100/Makefile
> + clean-files := *dtb.S
> +
> + DTC_FLAGS := -p 1024
> + obj-y += foo.dtb.o
> +
> + $(obj)/%.dtb: $(src)/%.dts
> + $(call if_changed,dtc)
When using "if_changed" you need to add your target to targets-y.
And you need to specify FORCE as a prerequisite to force kbuild
to use the if_changed logic.
The purpose of if_changed is to check if the commandlien has changed
and execute the command again also if the commandline has changed.
The simpler variant is $(call cmd,dtc) where you do not check
the command line and do not need FORCE.
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index bd69d79..024d3b9 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -23,7 +23,7 @@
> * _etext = .;
> *
> * _sdata = .;
> - * RO_DATA_SECTION(PAGE_SIZE)
> +* RO_DATA_SECTION(PAGE_SIZE)
> * RW_DATA_SECTION(...)
> * _edata = .;
> *
Change seems wrong.
> @@ -67,7 +67,8 @@
> * Align to a 32 byte boundary equal to the
> * alignment gcc 4.5 uses for a struct
> */
> -#define STRUCT_ALIGN() . = ALIGN(32)
> +#define STRUCT_ALIGNMENT 32
> +#define STRUCT_ALIGN() . = ALIGN(STRUCT_ALIGNMENT)
>
> /* The actual configuration determine if the init/exit sections
> * are handled as text/data or they can be discarded (which
> @@ -146,6 +147,13 @@
> #define TRACE_SYSCALLS()
> #endif
>
> +
> +#define KERNEL_DTB() \
> + STRUCT_ALIGN(); \
> + VMLINUX_SYMBOL(__dtb_start) = .; \
> + *(.dtb.init.rodata) \
> + VMLINUX_SYMBOL(__dtb_end) = .;
> +
> /* .data section */
> #define DATA_DATA \
> *(.data) \
> @@ -468,7 +476,8 @@
> MCOUNT_REC() \
> DEV_DISCARD(init.rodata) \
> CPU_DISCARD(init.rodata) \
> - MEM_DISCARD(init.rodata)
> + MEM_DISCARD(init.rodata) \
> + KERNEL_DTB()
>
> #define INIT_TEXT \
> *(.init.text) \
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 4c72c11..937eabbb 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -200,7 +200,26 @@ quiet_cmd_gzip = GZIP $@
> cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -f -9 > $@) || \
> (rm -f $@ ; false)
>
> -
> +# DTC
> +# ---------------------------------------------------------------------------
> +
> +# Generate an assembly file to wrap the output of the device tree compiler
> +$(obj)/%.dtb.S: $(obj)/%.dtb
> + @echo '#include <asm-generic/vmlinux.lds.h>' > $@
> + @echo '.section .dtb.init.rodata,"a"' >> $@
> + @echo '.balign STRUCT_ALIGNMENT' >> $@
> + @echo '.global __dtb_$(*F)_begin' >> $@
> + @echo '__dtb_$(*F)_begin:' >> $@
> + @echo '.incbin "$<" ' >> $@
> + @echo '__dtb_$(*F)_end:' >> $@
> + @echo '.global __dtb_$(*F)_end' >> $@
> + @echo '.balign STRUCT_ALIGNMENT' >> $@
> +
If we really want this rule in Makefile.lib then at least make it less verbose,
and more secure.
Something like this:
quiet_dt_S_dtb_cmd = DTB $@
dt_S_dtb_cmd = \
( \
@echo '#include <asm-generic/vmlinux.lds.h>'; \
@echo '.section .dtb.init.rodata,"a"'; \
@echo '.balign STRUCT_ALIGNMENT'; \
echo '.global __dtb_$(*F)_begin'; \
echo '__dtb_$(*F)_begin:'; \
echo '.incbin "$<" '; \
echo '__dtb_$(*F)_end:'; \
echo '.global __dtb_$(*F)_end'; \
echo '.balign STRUCT_ALIGNMENT'; \
) > $@
$(obj)/%.dtb.S: $(obj)/%.dtb
$(call cmd,dt_S_dtb)
> +DTC = $(objtree)/scripts/dtc/dtc
If this is the only spot where we use DTC then drop the variable.
> +
> +quiet_cmd_dtc = DTC $@
> + cmd_dtc = $(DTC) -O dtb -o $@ -b 0 $(DTC_FLAGS) $<
> +ooo
What is the purpose of these "ooo"? A debugging left-over?
Sam
On 12/06/2010 11:02 AM, Sam Ravnborg wrote:
> On Mon, Dec 06, 2010 at 09:35:59AM -0800, [email protected] wrote:
>> From: Dirk Brandewie<[email protected]>
>> -
>> +# DTC
>> +# ---------------------------------------------------------------------------
>> +
>> +# Generate an assembly file to wrap the output of the device tree compiler
>> +$(obj)/%.dtb.S: $(obj)/%.dtb
>> + @echo '#include<asm-generic/vmlinux.lds.h>'> $@
>> + @echo '.section .dtb.init.rodata,"a"'>> $@
>> + @echo '.balign STRUCT_ALIGNMENT'>> $@
>> + @echo '.global __dtb_$(*F)_begin'>> $@
>> + @echo '__dtb_$(*F)_begin:'>> $@
>> + @echo '.incbin "$<" '>> $@
>> + @echo '__dtb_$(*F)_end:'>> $@
>> + @echo '.global __dtb_$(*F)_end'>> $@
>> + @echo '.balign STRUCT_ALIGNMENT'>> $@
>> +
>
> If we really want this rule in Makefile.lib then at least make it less verbose,
> and more secure.
I started with the change in Makefile.lib because it made sense to me, is there
a more appropriate place for these rules/commands?
> Something like this:
> quiet_dt_S_dtb_cmd = DTB $@
> dt_S_dtb_cmd = \
> ( \
> @echo '#include<asm-generic/vmlinux.lds.h>'; \
> @echo '.section .dtb.init.rodata,"a"'; \
> @echo '.balign STRUCT_ALIGNMENT'; \
> echo '.global __dtb_$(*F)_begin'; \
> echo '__dtb_$(*F)_begin:'; \
> echo '.incbin "$<" '; \
> echo '__dtb_$(*F)_end:'; \
> echo '.global __dtb_$(*F)_end'; \
> echo '.balign STRUCT_ALIGNMENT'; \
> )> $@
>
> $(obj)/%.dtb.S: $(obj)/%.dtb
> $(call cmd,dt_S_dtb)
>
I will make the changes in next version.
>
>> +DTC = $(objtree)/scripts/dtc/dtc
>
> If this is the only spot where we use DTC then drop the variable.
>
>> +
>> +quiet_cmd_dtc = DTC $@
>> + cmd_dtc = $(DTC) -O dtb -o $@ -b 0 $(DTC_FLAGS) $<
>
>
>> +ooo
>
> What is the purpose of these "ooo"? A debugging left-over?
>
Yep sorry
>
> Sam