[U-Boot] [PATCH v4 3/4] configs: define CONFIG_SPL_SIZE_LIMIT

[Heinrich Schuchardt]

A new configuration variable CONFIG_SPL_SIZE_LIMIT is introduced to define
the board specific maximum size for the SPL file.

Use Makefile function size_check() to implement the test.

Depending on the size of CONFIG_SPL_SIZE_LIMIT an error like the following
is thrown:

spl/u-boot-spl.bin exceeds file size limit:
  limit:  30720 bytes
  actual: 33426 bytes
  excess: 2706 bytes
make: *** [Makefile:1663: spl/u-boot-spl.bin] Error 1

Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
v4
	use function size_check()
	split off change in tinker-rk3288_defconfig
---
 Kconfig  | 8 ++++++++
 Makefile | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/Kconfig b/Kconfig
index 305b265ed7..69212bf58f 100644
--- a/Kconfig
+++ b/Kconfig
@@ -172,6 +172,14 @@ config TPL_SYS_MALLOC_F_LEN
 	  particular needs this to operate, so that it can allocate the
 	  initial serial device and any others that are needed.

+config SPL_SIZE_LIMIT
+	int "Maximum size of SPL image"
+	depends on SPL
+	default 0
+	help
+	  Specifies the maximum length of the U-Boot SPL image.
+	  If this value is zero, it is ignored.
+
 menuconfig EXPERT
 	bool "Configure standard U-Boot features (expert users)"
 	default y
diff --git a/Makefile b/Makefile
index 6398117e64..073ef2b387 100644
--- a/Makefile
+++ b/Makefile
@@ -789,6 +789,12 @@ else
 BOARD_SIZE_CHECK =
 endif

+ifneq ($(CONFIG_SPL_SIZE_LIMIT),0)
+SPL_SIZE_CHECK = @$(call size_check,$@,$(CONFIG_SPL_SIZE_LIMIT))
+else
+SPL_SIZE_CHECK =
+endif
+
 # Statically apply RELA-style relocations (currently arm64 only)
 # This is useful for arm64 where static relocation needs to be performed on
 # the raw binary, but certain simulators only accept an ELF file (but don't
@@ -1654,6 +1660,8 @@ u-boot.lds: $(LDSCRIPT) prepare FORCE

 spl/u-boot-spl.bin: spl/u-boot-spl
 	@:
+	$(SPL_SIZE_CHECK)
+
 spl/u-boot-spl: tools prepare \
 		$(if $(CONFIG_OF_SEPARATE)$(CONFIG_OF_EMBED)$(CONFIG_SPL_OF_PLATDATA),dts/dt.dtb) \
 		$(if $(CONFIG_OF_SEPARATE)$(CONFIG_OF_EMBED)$(CONFIG_TPL_OF_PLATDATA),dts/dt.dtb)
--
2.20.1