gem5: support variants

gem5/build

@@ -1,9 +1,9 @@
 #!/usr/bin/env bash
-set -eu
+set -eux
 arch=x86_64
 cross_compile=
 j=
-outdir="$(pwd)/out"
+outdir="$(pwd)"
 while getopts a:c:j:o: OPT; do
   case "$OPT" in
     a)
@@ -28,7 +28,6 @@ system_dir="${outdir}/system"
 binaries_dir="${system_dir}/binaries"
 disks_dir="${system_dir}/disks"
 mkdir -p "$binaries_dir" "$disks_dir"
-cd "gem5"
 if [ "$arch" = x86_64 ]; then
   scons -j "$j" --ignore-style "${outdir}/build/X86/gem5.opt"
   f="${disks_dir}/linux-bigswap2.img"
@@ -41,7 +40,8 @@ elif [ "$arch" = arm ] || [ "$arch" = aarch64 ]; then
   scons -j "$j" --ignore-style "${outdir}/build/ARM/gem5.opt"
   make -C ./system/arm/dt/
   mkdir -p "${system_dir}/arm/dt"
-  cp ./system/arm/dt/*.dtb "${system_dir}/arm/dt"
+  # || true in case they are the same directory.
+  cp ./system/arm/dt/*.dtb "${system_dir}/arm/dt" || true
   # TODO use the buildroot cross compiler here, and remove the dependencies from configure.
   make -C ./system/arm/simple_bootloader/ $cross_compile
   cp ./system/arm/simple_bootloader/boot_emm.arm "$binaries_dir"

gem5/external.mk

@@ -15,10 +15,8 @@ ARCH_MAKE = $(ARCH)
 endif
 
 define GEM5_BUILD_CMDS
-	# Cannot pass "-c '$(TARGET_CROSS)'" here because the ARM build uses aarch64 for the bootloader...
-	cd '$(GEM5_SITE)' && ./build -a '$(ARCH)' -j '$(BR2_JLEVEL)' -o '$(GEM5_SITE)/../out/common/gem5'
-	# This would build inside the buildroot directory as a more normal package.
-	#cd '$(@D)' && ./build -a '$(ARCH)' -j '$(BR2_JLEVEL)'
+	# TODO cannot pass "-c '$(TARGET_CROSS)'" here because the ARM build uses aarch64 for the bootloader...
+	cd '$(GEM5_LKMC_SRCDIR)' && '$(GEM5_SITE)/build' -a '$(ARCH)' -j '$(BR2_JLEVEL)' -o '$(GEM5_LKMC_OUTDIR)'
 
 	# TODO cannot use TARGET_CONFIGURE_OPTS here because it overrides the CFLAGS on m5,
 	# which have an include. We should patch gem5 to add a += instead of = there.