ihex: add ihex2fw tool for converting HEX files into firmware images

Not the straight conversion to binary which objcopy can do for us, but
actually representing each record with its original {addr, length},
because some drivers need that information preserved.

Fix up 'firmware_install' to be able to build $(hostprogs-y) too.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/firmware/Makefile b/firmware/Makefile
index 3742feeb066f..9e780a331e10 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -32,6 +32,9 @@ quiet_cmd_mkdir = MKDIR   $(patsubst $(objtree)/%,%,$@)
 quiet_cmd_ihex  = IHEX    $@
       cmd_ihex  = $(OBJCOPY) -Iihex -Obinary $< $@
 
+quiet_cmd_ihex2fw  = IHEX2FW $@
+      cmd_ihex2fw  = $(objtree)/$(obj)/ihex2fw $< $@
+
 quiet_cmd_fwbin = MK_FW   $@
       cmd_fwbin = FWNAME="$(patsubst firmware/%.gen.S,%,$@)";                \
                   FWSTR="$(subst /,_,$(subst .,_,$(subst -,_,$(patsubst      \
@@ -84,9 +87,18 @@ $(patsubst %,$(obj)/%.gen.S, $(fw-external-y)): %: $(wordsize_deps) \
 $(patsubst %,$(obj)/%.gen.o, $(fw-shipped-y)): %.gen.o: %
 $(patsubst %,$(obj)/%.gen.o, $(fw-external-y)): $(obj)/%.gen.o: $(fwdir)/%
 
+# .ihex is used just as a simple way to hold binary files in a source tree
+# where binaries are frowned upon. They are directly converted with objcopy.
 $(obj)/%: $(obj)/%.ihex | $(objtree)/$(obj)/$$(dir %)
         $(call cmd,ihex)
 
+# .HEX is also Intel HEX, but where the offset and length in each record
+# is actually meaningful, because the firmware has to be loaded in a certain
+# order rather than as a single binary blob. Thus, we convert them into our
+# more compact binary representation of ihex records (<linux/ihex.h>)
+$(obj)/%.fw: $(obj)/%.HEX $(obj)/ihex2fw | $(objtree)/$(obj)/$$(dir %)
+        $(call cmd,ihex2fw)
+
 $(firmware-dirs):
         $(call cmd,mkdir)
 
@@ -101,3 +113,5 @@ targets := $(fw-shipped-) $(patsubst $(obj)/%,%, \
 # Without this, built-in.o won't be created when it's empty, and the
 # final vmlinux link will fail.
 obj-n := dummy
+
+hostprogs-y := ihex2fw