[BOOTWRAPPER PATCH 1/2] Introduce --with-gic option

[Vladimir Murzin]

We are about adding support for another GIC version, so introduce a
new --with-gic option to select the desired GIC version at configure
time. The default remains v2, preserving existing behavior.  Howevere,
for GICv3, we replace the previous --enable-gicv3 option with
--with-gic=v3 which is backward-incompatible change.

Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
---

I do not know how much we care about backward compatibility...

 Makefile.am                |  8 +++++---
 common/{gic.c => gic-v2.c} |  0
 configure.ac               | 23 ++++++++++++++++-------
 3 files changed, 21 insertions(+), 10 deletions(-)
 rename common/{gic.c => gic-v2.c} (100%)

diff --git a/Makefile.am b/Makefile.am
index 0178e5d..2710494 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -87,15 +87,17 @@ GIC_DIST_BASE	:= $(shell perl -I $(SCRIPT_DIR) $(SCRIPT_DIR)/findbase.pl $(KERNE
 GIC_RDIST_BASE	:= $(shell perl -I $(SCRIPT_DIR) $(SCRIPT_DIR)/findbase.pl $(KERNEL_DTB) 1 'arm,gic-v3')
 DEFINES		+= -DGIC_DIST_BASE=$(GIC_DIST_BASE)
 DEFINES		+= -DGIC_RDIST_BASE=$(GIC_RDIST_BASE)
-COMMON_OBJ	+= gic-v3.o
-else
+endif
+
+if GICV2
 GIC_DIST_BASE	:= $(shell perl -I $(SCRIPT_DIR) $(SCRIPT_DIR)/findbase.pl $(KERNEL_DTB) 0 'arm,cortex-a15-gic')
 GIC_CPU_BASE	:= $(shell perl -I $(SCRIPT_DIR) $(SCRIPT_DIR)/findbase.pl $(KERNEL_DTB) 1 'arm,cortex-a15-gic')
 DEFINES		+= -DGIC_CPU_BASE=$(GIC_CPU_BASE)
 DEFINES		+= -DGIC_DIST_BASE=$(GIC_DIST_BASE)
-COMMON_OBJ	+= gic.o
 endif
 
+COMMON_OBJ	+= gic-$(GIC_VERSION).o
+
 if KERNEL_32
 MBOX_OFFSET	:= 0x7ff8
 TEXT_LIMIT	:= 0x3000
diff --git a/common/gic.c b/common/gic-v2.c
similarity index 100%
rename from common/gic.c
rename to common/gic-v2.c
diff --git a/configure.ac b/configure.ac
index 42858df..6f486c4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -139,12 +139,21 @@ AC_ARG_WITH([xen-cmdline],
 	[X_CMDLINE=$withval])
 AC_SUBST([XEN_CMDLINE], [$X_CMDLINE])
 
-# Allow a user to pass --enable-gicv3
-AC_ARG_ENABLE([gicv3],
-	AS_HELP_STRING([--enable-gicv3], [enable GICv3 instead of GICv2]),
-	[USE_GICV3=$enableval])
-AM_CONDITIONAL([GICV3], [test "x$USE_GICV3" = "xyes"])
-AS_IF([test "x$USE_GICV3" = "xyes"], [], [USE_GICV3=no])
+
+AC_ARG_WITH([gic],
+  AS_HELP_STRING([--with-gic={v2|v3}], [select GIC version]),
+  [GIC_VERSION=$withval],
+  [GIC_VERSION=v2])
+
+AS_CASE([$GIC_VERSION],
+  [v2|v3], [],
+  [AC_MSG_ERROR([Invalid GIC version: $GIC_VERSION (use v2 or v3)])])
+
+AC_SUBST([GIC_VERSION], [$GIC_VERSION])
+
+AM_CONDITIONAL([GICV2], [test "x$GIC_VERSION" = "xv2"])
+AM_CONDITIONAL([GICV3], [test "x$GIC_VERSION" = "xv3"])
+
 
 # Ensure that we have all the needed programs
 AC_PROG_CC
@@ -174,7 +183,7 @@ echo "  Device tree compiler:              ${DTC}"
 echo "  Linux kernel command line:         ${CMDLINE}"
 echo "  Embedded initrd:                   ${FILESYSTEM:-NONE}"
 echo "  Use PSCI?                          ${USE_PSCI}"
-echo "  Use GICv3?                         ${USE_GICV3}"
+echo "  GIC version:                       ${GIC_VERSION}"
 echo "  Boot-wrapper execution state:      AArch${BOOTWRAPPER_ES}"
 echo "  Kernel execution state:            AArch${KERNEL_ES}"
 echo "  Xen image                          ${XEN_IMAGE:-NONE}"
-- 
2.34.1