mirror of
https://github.com/torvalds/linux
synced 2024-09-06 18:01:05 +00:00
of: Add support for linking device tree blobs into vmlinux
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 <dirk.brandewie@gmail.com> Acked-by: Michal Marek <mmarek@suse.cz> [grant.likely@secretlab.ca: cleaned up whitespace inconsistencies] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
parent
cfb13c5db0
commit
aab94339cd
|
@ -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 cmd,dtc)
|
||||
|
||||
--- 6.7 Custom kbuild commands
|
||||
|
||||
|
|
|
@ -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) \
|
||||
|
|
|
@ -200,6 +200,29 @@ 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
|
||||
quiet_cmd_dt_S_dtb= DTB $@
|
||||
cmd_dt_S_dtb= \
|
||||
( \
|
||||
echo '\#include <asm-generic/vmlinux.lds.h>'; \
|
||||
echo '.section .dtb.init.rodata,"a"'; \
|
||||
echo '.balign STRUCT_ALIGNMENT'; \
|
||||
echo '.global __dtb_$(*F)_begin'; \
|
||||
echo '__dtb_$(*F)_begin:'; \
|
||||
echo '.incbin "$<" '; \
|
||||
echo '__dtb_$(*F)_end:'; \
|
||||
echo '.global __dtb_$(*F)_end'; \
|
||||
echo '.balign STRUCT_ALIGNMENT'; \
|
||||
) > $@
|
||||
|
||||
$(obj)/%.dtb.S: $(obj)/%.dtb
|
||||
$(call cmd,dt_S_dtb)
|
||||
|
||||
quiet_cmd_dtc = DTC $@
|
||||
cmd_dtc = $(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 $(DTC_FLAGS) $<
|
||||
|
||||
# Bzip2
|
||||
# ---------------------------------------------------------------------------
|
||||
|
|
Loading…
Reference in a new issue