soc/intel/fast_spi/Makefile: Rewrite 16mib check for legibility

Perform some cosmetical changes:

* Override the first prerequisite so we can use `$<`.
* Add/remove whitspace to align things (recipe needs to be indented
  by a single tab only).
* We can use shell variables inside double quotes. To make the
  end of the variable name clear, use braces, e.g. "${x}".
  NB. Most of the double quotes are unnecessary. They only change
  the way the script would be failing in case of spurious whitespace.
* Break some lines doing multiple things at once.
* To reduce remaining clutter, put reading numbers into a shell
  function.

And functional changes:

* No need to spawn `cat`, the shell can redirect input as well as
  output (using `<`).
* To read a number from the `fmap_config.h`, we spawned 4 processes
  where a single one can achieve the same. With one exception: GNU
  awk refuses to parse hex numbers by default. Luckily, it turned
  out that we don't need intermediate decimal numbers: Shells can
  do arithmetic with hex values as well.

Change-Id: Ia7bfba0d7864fc091ee6003e09b705fd7254e99b
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51325
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>

1 files changed, 19 insertions, 10 deletions

diff --git a/src/soc/intel/common/block/fast_spi/Makefile.inc b/src/soc/intel/common/block/fast_spi/Makefile.inc
index 75596de75b..eeaae51d75 100644
--- a/src/soc/intel/common/block/fast_spi/Makefile.inc
+++ b/src/soc/intel/common/block/fast_spi/Makefile.inc
@@ -35,16 +35,25 @@ smm-y += mmap_boot.c
 # Check to ensure that no sections in the FMAP cross 16MiB boundary if
 # the platform supports split decode windows for BIOS region greater
 # than 16MiB.
-$(call add_intermediate, check-fmap-16mib-crossing, $(obj)/fmap_config.h)
-		flash_offset=$$(printf "%d" $$(cat $(obj)/fmap_config.h | grep "FMAP_SECTION_FLASH_START" | awk '{print $$NF}')); \
-		for x in $$(cat $(obj)/fmap_config.h | grep "FMAP_TERMINAL_SECTIONS" | cut -d\" -f2); do \
-		    start=$$(printf "%d" $$(cat $(obj)/fmap_config.h | grep "FMAP_SECTION_"$$x"_START" | awk '{print $$NF}')); \
-		    size=$$(printf "%d" $$(cat $(obj)/fmap_config.h | grep "FMAP_SECTION_"$$x"_SIZE" | awk '{print $$NF}')); \
-		    start=$$((start-flash_offset)); \
-		    end=$$((start+size-1)); \
-		    if [ $$start -lt 16777216 ] && [ $$end -ge 16777216 ]; then echo "ERROR:" $$x "crosses 16MiB boundary"; fail=1; break; fi; \
-		done; \
-		exit $$fail
+
+$(call add_intermediate, check-fmap-16mib-crossing)
+check-fmap-16mib-crossing: $(obj)/fmap_config.h
+	fmap_get() { awk "/$$1/ { print \$$NF }" < $<; };		\
+									\
+	flash_offset=$$(fmap_get FMAP_SECTION_FLASH_START);		\
+	for x in $$(grep "FMAP_TERMINAL_SECTIONS" < $< | cut -d\" -f2);	\
+	do								\
+	    start=$$(fmap_get "FMAP_SECTION_$${x}_START");		\
+	    size=$$(fmap_get "FMAP_SECTION_$${x}_SIZE");		\
+	    start=$$((start-flash_offset));				\
+	    end=$$((start+size-1));					\
+	    if [ $$start -lt 16777216 ] && [ $$end -ge 16777216 ]; then	\
+	        echo "ERROR: $$x crosses 16MiB boundary";		\
+	        fail=1;							\
+	        break;							\
+	    fi;								\
+	done;								\
+	exit $$fail
 
 CBFSTOOL_ADD_CMD_OPTIONS += --ext-win-base $(CONFIG_EXT_BIOS_WIN_BASE) --ext-win-size $(CONFIG_EXT_BIOS_WIN_SIZE)