diff --git a/README.md b/README.md
index 029ff0f..fdae0d7 100644
--- a/README.md
+++ b/README.md
@@ -45,7 +45,7 @@ Note: if you are using Nix channels the first time, you need to be aware of this
 Pure build with Nix and execution on a remote JTAG server:
 
 ```shell
-nix-build -A zc706-nist_clock-jtag  # or zc706-nist_qc2-jtag or zc706-nist_clock_satellite-jtag
+nix-build -A zc706-nist_clock-jtag  # or zc706-nist_qc2-jtag or zc706-nist_clock_satellite-jtag etc.
 ./remote_run.sh
 ```
 
@@ -54,8 +54,8 @@ Impure incremental build and execution on a remote JTAG server:
 ```shell
 nix-shell
 cd src
-gateware/zc706.py -g ../build/gateware  # build gateware
-make                                    # build firmware
+gateware/zc706.py -g ../build/gateware -v <variant> # build gateware
+make GWARGS="-v <variant>" <runtime/satman>    # build firmware
 cd ..
 ./remote_run.sh -i
 ```
@@ -64,6 +64,8 @@ Notes:
 
 - This is developed with Nixpkgs 21.05, and the ``nixbld.m-labs.hk`` binary substituter can also be used here (see the ARTIQ manual for the public key and instructions).
 - The impure build process is also compatible with non-Nix systems.
+- When calling make, you need to specify both the variant and firmware type.
+- Firmware type must be either ``runtime`` for DRTIO-less or DRTIO master variants, or ``satman`` for DRTIO satellite.
 - If the board is connected to the local machine, use the ``local_run.sh`` script.
 - To update ``zynq-rs``, update the cargo files as per usual for Rust projects, but also keep ``zynq-rs.nix`` in sync.
 
diff --git a/default.nix b/default.nix
index dbac0c1..40ce07d 100644
--- a/default.nix
+++ b/default.nix
@@ -35,7 +35,7 @@ let
         export XARGO_RUST_SRC="${rustPlatform.rust.rustc}/lib/rustlib/src/rust/library"
         export CLANG_EXTRA_INCLUDE_DIR="${pkgs.llvmPackages_9.clang-unwrapped.lib}/lib/clang/9.0.1/include"
         export CARGO_HOME=$(mktemp -d cargo-home.XXX)
-        make TARGET=${target} GWARGS="${if json == null then "-V ${variant}" else json}" ../build/${fwtype}.bin
+        make TARGET=${target} GWARGS="${if json == null then "-V ${variant}" else json}" ${fwtype}
       '';
 
       installPhase = ''
diff --git a/src/Makefile b/src/Makefile
index 12f33a7..f12fb29 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,15 +1,19 @@
 TARGET := zc706
 GWARGS := -V nist_clock
 
-all: ../build/runtime.bin
+all: runtime
 
-.PHONY: all
+runtime: ../build/runtime.bin
+
+satman: ../build/satman.bin
+
+.PHONY: all runtime_target satman_target
 
 ../build/pl.rs ../build/rustc-cfg ../build/mem.rs: gateware/* 
 	mkdir -p ../build
 	python gateware/$(TARGET).py -r ../build/pl.rs -c ../build/rustc-cfg -m ../build/mem.rs $(GWARGS)
 
-../build/firmware/armv7-none-eabihf/release/runtime: ../build/pl.rs ../build/rustc-cfg ../build/mem.rs $(shell find . -print)
+../build/firmware/armv7-none-eabihf/release/runtime: ../build/pl.rs ../build/rustc-cfg ../build/mem.rs $(shell find . -type f -print)
 	cd runtime && \
 	XBUILD_SYSROOT_PATH=`pwd`/../../build/sysroot \
 	cargo xbuild --release \
@@ -19,7 +23,7 @@ all: ../build/runtime.bin
 ../build/runtime.bin: ../build/firmware/armv7-none-eabihf/release/runtime
 	llvm-objcopy -O binary ../build/firmware/armv7-none-eabihf/release/runtime ../build/runtime.bin
 
-../build/firmware/armv7-none-eabihf/release/satman: ../build/pl.rs ../build/rustc-cfg ../build/mem.rs $(shell find . -print)
+../build/firmware/armv7-none-eabihf/release/satman: ../build/pl.rs ../build/rustc-cfg ../build/mem.rs $(shell find . -type f -print)
 	cd satman && \
 	XBUILD_SYSROOT_PATH=`pwd`/../../build/sysroot \
 	cargo xbuild --release \