The SPL device tree size must be minimised to save memory. Only include properties that are needed by SPL - this is determined by the presence of the "u-boot,dm-pre-reloc" property. Also remove a predefined list of unused properties from the nodes that remain.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v2: - Add new patch to reduce SPL device tree size with fdtgrep
Makefile | 2 +- arch/arm/cpu/u-boot-spl.lds | 2 +- dts/Kconfig | 12 ++++++++++++ scripts/Makefile.spl | 28 ++++++++++++++++++++++++++++ 4 files changed, 42 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile index cecb8fa..c82ca3d 100644 --- a/Makefile +++ b/Makefile @@ -1255,7 +1255,7 @@ u-boot.lds: $(LDSCRIPT) prepare FORCE
spl/u-boot-spl.bin: spl/u-boot-spl @: -spl/u-boot-spl: tools prepare +spl/u-boot-spl: tools prepare $(if $(CONFIG_OF_SEPARATE),dts/dt.dtb) $(Q)$(MAKE) obj=spl -f $(srctree)/scripts/Makefile.spl all
spl/sunxi-spl.bin: spl/u-boot-spl diff --git a/arch/arm/cpu/u-boot-spl.lds b/arch/arm/cpu/u-boot-spl.lds index a8be204..4b6e0f6 100644 --- a/arch/arm/cpu/u-boot-spl.lds +++ b/arch/arm/cpu/u-boot-spl.lds @@ -66,7 +66,7 @@ SECTIONS . = ALIGN(4); __bss_end = .; } - + __bss_size = __bss_end - __bss_start; .dynsym _image_binary_end : { *(.dynsym) } .dynbss : { *(.dynbss) } .dynstr : { *(.dynstr*) } diff --git a/dts/Kconfig b/dts/Kconfig index 957f5c7..7825b4e 100644 --- a/dts/Kconfig +++ b/dts/Kconfig @@ -56,4 +56,16 @@ config DEFAULT_DEVICE_TREE It can be overridden from the command line: $ make DEVICE_TREE=<device-tree-name>
+config OF_SPL_REMOVE_PROPS + string "List of device tree properties to drop for SPL" + depends on OF_CONTROL && SPL + default "pinctrl-0 pinctrl-names clocks clock-names interrupts interrupt-parent" + help + Since SPL normally runs in a reduced memory space, the device tree + is cut down to only what is needed to load and start U-Boot. Only + nodes marked with the property "u-boot,dm-pre-reloc" will be + included. In addition, some properties are not used by U-Boot and + can be discarded. This option defines the list of properties to + discard. + endmenu diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl index ea67137..33c36e6 100644 --- a/scripts/Makefile.spl +++ b/scripts/Makefile.spl @@ -151,6 +151,8 @@ boot.bin: $(obj)/u-boot-spl.bin
ALL-y += $(obj)/$(SPL_BIN).bin $(obj)/$(SPL_BIN).cfg
+ALL-$(CONFIG_OF_SEPARATE) += $(obj)/$(SPL_BIN)-pad.bin $(obj)/$(SPL_BIN)-dtb.bin + ifdef CONFIG_SAMSUNG ALL-y += $(obj)/$(BOARD)-spl.bin endif @@ -165,6 +167,32 @@ endif
all: $(ALL-y)
+quiet_cmd_cat = CAT $@ +cmd_cat = cat $(filter-out $(PHONY), $^) > $@ + +$(obj)/$(SPL_BIN)-dtb.bin: $(obj)/$(SPL_BIN).bin $(obj)/$(SPL_BIN)-pad.bin \ + $(obj)/$(SPL_BIN).dtb FORCE + $(call if_changed,cat) + +# Create a file that pads from the end of u-boot-spl.bin to bss_end +$(obj)/$(SPL_BIN)-pad.bin: $(obj)/$(SPL_BIN) + @bss_size_str=$(shell $(NM) $< | awk 'BEGIN {size = 0} /__bss_size/ {size = $$1} END {print "ibase=16; " size}' | bc); \ + dd if=/dev/zero of=$@ bs=1 count=$${bss_size_str} 2>/dev/null; + +# Pass the original device tree file through fdtgrep twice. The first pass +# removes any unwanted nodes (i.e. those which don't have the +# 'u-boot,dm-pre-reloc' property and thus are not needed by SPL. The second +# pass removes various unused properties from the remaining nodes. +# The output is typically a much smaller device tree file. +quiet_cmd_fdtgrep = FDTGREP $@ + cmd_fdtgrep = $(objtree)/tools/fdtgrep -b u-boot,dm-pre-reloc -RT $< \ + -n /chosen -O dtb | \ + $(objtree)/tools/fdtgrep -r -O dtb - -o $@ \ + $(addprefix -P ,$(subst $",,$(CONFIG_OF_SPL_REMOVE_PROPS))) + +$(obj)/$(SPL_BIN).dtb: dts/dt.dtb + $(call cmd,fdtgrep) + quiet_cmd_cpp_cfg = CFG $@ cmd_cpp_cfg = $(CPP) -Wp,-MD,$(depfile) $(cpp_flags) $(LDPPFLAGS) -ansi \ -D__ASSEMBLY__ -x assembler-with-cpp -P -dM -E -o $@ $<