Commit fa78e0a3 authored by Simon Glass's avatar Simon Glass
Browse files

dm: Reduce SPL device tree size

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: default avatarSimon Glass <>
parent 1043d0a0
......@@ -1259,7 +1259,7 @@ $(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
......@@ -66,7 +66,7 @@ SECTIONS
. = ALIGN(4);
__bss_end = .;
__bss_size = __bss_end - __bss_start;
.dynsym _image_binary_end : { *(.dynsym) }
.dynbss : { *(.dynbss) }
.dynstr : { *(.dynstr*) }
......@@ -56,4 +56,16 @@ config DEFAULT_DEVICE_TREE
It can be overridden from the command line:
$ make DEVICE_TREE=<device-tree-name>
string "List of device tree properties to drop for SPL"
depends on OF_CONTROL && SPL
default "pinctrl-0 pinctrl-names clocks clock-names interrupt-parent"
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
......@@ -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
ALL-y += $(obj)/$(BOARD)-spl.bin
......@@ -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 = $$1} END {print "ibase=16; " toupper(size)}' | bc); \
dd if=/dev/zero of=$@ bs=1 count=$${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 \
-DDO_DEPS_ONLY -D__ASSEMBLY__ -x assembler-with-cpp -P -dM -E -o $@ $<
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