build: remove Windows compatibility layer

For a couple of releases now we have officially withdrawn support for
building TF-A on Windows using the native environment, relying instead
on POSIX emulation layers like MSYS2, Mingw64, Cygwin or WSL.

This change removes the remainder of the OS compatibility layer
entirely, and migrates the build system over to explicitly relying on a
POSIX environment.

Change-Id: I8fb60d998162422e958009afd17eab826e3bc39b
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/Makefile b/Makefile
index a286a4a..b8e9e12 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2025, Arm Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -23,7 +23,6 @@
 
 MAKE_HELPERS_DIRECTORY := make_helpers/
 include ${MAKE_HELPERS_DIRECTORY}build_macros.mk
-include ${MAKE_HELPERS_DIRECTORY}build_env.mk
 include ${MAKE_HELPERS_DIRECTORY}build-rules.mk
 include ${MAKE_HELPERS_DIRECTORY}common.mk
 
@@ -99,15 +98,15 @@
 
 # Variables for use with Certificate Generation Tool
 CRTTOOLPATH		?=	tools/cert_create
-CRTTOOL			?=	${CRTTOOLPATH}/cert_create${BIN_EXT}
+CRTTOOL			?=	${CRTTOOLPATH}/cert_create$(.exe)
 
 # Variables for use with Firmware Encryption Tool
 ENCTOOLPATH		?=	tools/encrypt_fw
-ENCTOOL			?=	${ENCTOOLPATH}/encrypt_fw${BIN_EXT}
+ENCTOOL			?=	${ENCTOOLPATH}/encrypt_fw$(.exe)
 
 # Variables for use with Firmware Image Package
 FIPTOOLPATH		?=	tools/fiptool
-FIPTOOL			?=	${FIPTOOLPATH}/fiptool${BIN_EXT}
+FIPTOOL			?=	${FIPTOOLPATH}/fiptool$(.exe)
 
 # Variables for use with sptool
 SPTOOLPATH		?=	tools/sptool
@@ -1646,29 +1645,17 @@
 
 clean:
 	$(s)echo "  CLEAN"
-	$(call SHELL_REMOVE_DIR,${BUILD_PLAT})
-ifdef UNIX_MK
+	$(q)rm -rf $(BUILD_PLAT)
 	$(q)${MAKE} --no-print-directory -C ${FIPTOOLPATH} clean
-else
-# Clear the MAKEFLAGS as we do not want
-# to pass the gnumake flags to nmake.
-	$(q)set MAKEFLAGS= && ${MSVC_NMAKE} /nologo /f ${FIPTOOLPATH}/Makefile.msvc FIPTOOLPATH=$(subst /,\,$(FIPTOOLPATH)) FIPTOOL=$(subst /,\,$(FIPTOOL)) clean
-endif #(UNIX_MK)
 	$(q)${MAKE} PLAT=${PLAT} --no-print-directory -C ${CRTTOOLPATH} clean
 	$(q)${MAKE} PLAT=${PLAT} --no-print-directory -C ${ENCTOOLPATH} clean
 	$(q)${MAKE} --no-print-directory -C ${ROMLIBPATH} clean
 
 realclean distclean:
 	$(s)echo "  REALCLEAN"
-	$(call SHELL_REMOVE_DIR,${BUILD_BASE})
-	$(call SHELL_DELETE_ALL, ${CURDIR}/cscope.*)
-ifdef UNIX_MK
+	$(q)rm -rf $(BUILD_BASE)
+	$(q)rm -rf $(CURDIR)/cscope.*
 	$(q)${MAKE} --no-print-directory -C ${FIPTOOLPATH} clean
-else
-# Clear the MAKEFLAGS as we do not want
-# to pass the gnumake flags to nmake.
-	$(q)set MAKEFLAGS= && ${MSVC_NMAKE} /nologo /f ${FIPTOOLPATH}/Makefile.msvc FIPTOOLPATH=$(subst /,\,$(FIPTOOLPATH)) FIPTOOL=$(subst /,\,$(FIPTOOL)) realclean
-endif #(UNIX_MK)
 	$(q)${MAKE} PLAT=${PLAT} --no-print-directory -C ${CRTTOOLPATH} realclean
 	$(q)${MAKE} PLAT=${PLAT} --no-print-directory -C ${ENCTOOLPATH} realclean
 	$(q)${MAKE} --no-print-directory -C ${ROMLIBPATH} clean
@@ -1753,25 +1740,14 @@
 fwu_fip: ${BUILD_PLAT}/${FWU_FIP_NAME}
 
 ${FIPTOOL}: FORCE
-ifdef UNIX_MK
 	$(q)${MAKE} PLAT=${PLAT} CPPFLAGS="-DVERSION='\"${VERSION_STRING}\"'" FIPTOOL=${FIPTOOL} OPENSSL_DIR=${OPENSSL_DIR} DEBUG=${DEBUG} --no-print-directory -C ${FIPTOOLPATH} all
-else
-# Clear the MAKEFLAGS as we do not want
-# to pass the gnumake flags to nmake.
-	$(q)set MAKEFLAGS= && ${MSVC_NMAKE} /nologo /f ${FIPTOOLPATH}/Makefile.msvc FIPTOOLPATH=$(subst /,\,$(FIPTOOLPATH)) FIPTOOL=$(subst /,\,$(FIPTOOL))
-endif #(UNIX_MK)
 
 $(BUILD_PLAT)/romlib/romlib.bin $(BUILD_PLAT)/lib/libwrappers.a $&: $(BUILD_PLAT)/lib/libfdt.a $(BUILD_PLAT)/lib/libc.a $(CRYPTO_LIB)
 	$(q)${MAKE} PLAT_DIR=${PLAT_DIR} BUILD_PLAT=${BUILD_PLAT} ENABLE_BTI=${ENABLE_BTI} CRYPTO_SUPPORT=${CRYPTO_SUPPORT} ARM_ARCH_MINOR=${ARM_ARCH_MINOR} INCLUDES=$(call escape-shell,$(INCLUDES)) DEFINES=$(call escape-shell,$(DEFINES)) --no-print-directory -C ${ROMLIBPATH} all
 
 memmap: all
-ifdef UNIX_MK
 	$(q)PYTHONPATH=${CURDIR}/tools/memory \
 		${PYTHON} -m memory.memmap -sr ${BUILD_PLAT}
-else
-	$(q)set PYTHONPATH=${CURDIR}/tools/memory && \
-		${PYTHON} -m memory.memmap -sr ${BUILD_PLAT}
-endif
 
 tl: ${BUILD_PLAT}/tl.bin
 ${BUILD_PLAT}/tl.bin: ${HW_CONFIG}