Added --with-abi configure option (#183)

* Added --with-abi configure option

* Revised to preserve original semantics when user specifies --with-arch but not --with-abi or when the user specifies --with-arch but not --host.

Makefile.in

@@ -50,14 +50,23 @@ else
   project_ver:=@PACKAGE_VERSION@
 endif
 
-# If --with-arch is not specified, it defaults to whatever the compiler's
-# default is. The -with-abi is not necessary for this project. Unconditionally
-# compile it with a no-float ABI. i.e., ilp32 for 32-bit and lp64 for 64-bit.
+# The user may specify the host ISA (--with-arch) or host ABI (--with-abi).
+# *** If neither are given, they use the compiler's defaults.
+# *** If --with-arch is given but --with-abi is not, then the ABI defaults to 
+#     ilp32 or lp64, as appropriate for the ISA.
+# *** If --with-abi is given but --with-arch is not, then the ISA uses the
+#     compiler's default.
 
 ifneq (@WITH_ARCH@,)
   march := -march=@WITH_ARCH@
   is_32bit := $(findstring 32,$(march))
-  mabi := -mabi=$(if $(is_32bit),ilp32,lp64)
+  ifeq (@WITH_ABI@,)
+    mabi := -mabi=$(if $(is_32bit),ilp32,lp64)
+  endif
+endif
+
+ifneq (@WITH_ABI@,)
+  mabi := -mabi=@WITH_ABI@
 endif
 
 # Installation directories

configure

@@ -594,6 +594,7 @@ BBL_LOGO_FILE
 BBL_PAYLOAD
 BBL_ENABLE_LOGO
 MEM_START
+WITH_ABI
 WITH_ARCH
 RISCV
 EGREP
@@ -671,6 +672,7 @@ ac_user_opts='
 enable_option_checking
 enable_stow
 with_arch
+with_abi
 enable_print_device_tree
 with_mem_start
 enable_optional_subprojects
@@ -1323,6 +1325,7 @@ Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
   --with-arch             Set the RISC-V architecture
+  --with-abi              Set the RISC-V ABI
   --with-mem-start        Set physical memory start address
   --with-payload          Set ELF payload for bbl
   --with-logo             Specify a better logo
@@ -4073,6 +4076,14 @@ if test "${with_arch+set}" = set; then :
 fi
 
 
+
+# Check whether --with-abi was given.
+if test "${with_abi+set}" = set; then :
+  withval=$with_abi; WITH_ABI=$with_abi
+
+fi
+
+
 # Check whether --enable-print-device-tree was given.
 if test "${enable_print_device_tree+set}" = set; then :
   enableval=$enable_print_device_tree;

configure.ac

@@ -83,6 +83,9 @@ AC_ARG_VAR(RISCV, [top-level RISC-V install directory])
 AC_ARG_WITH([arch], AS_HELP_STRING([--with-arch], [Set the RISC-V architecture]),
   [AC_SUBST([WITH_ARCH], $with_arch, [Specify architecture to build the project])])
 
+AC_ARG_WITH([abi], AS_HELP_STRING([--with-abi], [Set the RISC-V ABI]),
+  [AC_SUBST([WITH_ABI], $with_abi, [Specify ABI to build the project])])
+
 AC_ARG_ENABLE([print-device-tree], AS_HELP_STRING([--enable-print-device-tree], [Print DTS when booting]))
 AS_IF([test "x$enable_print_device_tree" = "xyes"], [
   AC_DEFINE([PK_PRINT_DEVICE_TREE],,[Define if the DTS is to be displayed])