diff --git a/Dockerfile b/Dockerfile
index 8617eaa191..71bedcbbb6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,22 +4,28 @@ FROM debian:9
 
 # install build tools and dependencies
 
+ARG EMULATOR=0
+ENV EMULATOR=$EMULATOR
+
 RUN apt-get update && \
-    apt-get install -y \
-    build-essential curl unzip git python3 python3-pip \
-    gcc-arm-none-eabi libnewlib-arm-none-eabi
+    apt-get install -y build-essential curl git python3 python3-pip
+
+RUN if [ "$EMULATOR" = 1 ]; then \
+        apt-get install -y libsdl2-dev libsdl2-image-dev; \
+    else \
+        apt-get install -y gcc-arm-none-eabi libnewlib-arm-none-eabi; \
+    fi
 
 ENV PROTOBUF_VERSION=3.4.0
 RUN curl -LO "https://github.com/google/protobuf/releases/download/v${PROTOBUF_VERSION}/protoc-${PROTOBUF_VERSION}-linux-x86_64.zip"
 
 ENV PYTHON=python3
+ENV LC_ALL=C.UTF-8
+ENV LANG=C.UTF-8
 
 # use zipfile module to extract files world-readable
 RUN $PYTHON -m zipfile -e "protoc-${PROTOBUF_VERSION}-linux-x86_64.zip" /usr/local && chmod 755 /usr/local/bin/protoc
 
-ENV LC_ALL=C.UTF-8
-ENV LANG=C.UTF-8
-
 ENV WORKON_HOME=/tmp/.venvs
 
 RUN $PYTHON -m pip install pipenv
diff --git a/README.md b/README.md
index 75b0a110d4..0b8435ff59 100644
--- a/README.md
+++ b/README.md
@@ -4,23 +4,40 @@
 
 https://trezor.io/
 
-## How to build the TREZOR bootloader and firmware?
+## How to build the TREZOR bootloader, firmware and emulator
 
-1. [Install Docker](https://docs.docker.com/engine/installation/)
-2. `git clone https://github.com/trezor/trezor-mcu.git`
-3. `cd trezor-mcu`
-4. `./build.sh BOOTLOADER_TAG FIRMWARE_TAG` (where BOOTLOADER_TAG is bl1.5.0 and FIRMWARE_TAG is v1.7.0 for example, if left blank the script builds latest commit in master branch)
+Ensure that you have Docker installed. You can follow [Docker's installation instructions](https://docs.docker.com/engine/installation/).
 
-This creates the files `build/bootloader-BOOTLOADER_TAG.bin` and `build/trezor-FIRMWARE_TAG.bin` and prints their fingerprints and sizes at the end of the build log.
+Clone this repository:
+```sh
+git clone https://github.com/trezor/trezor-mcu.git`
+cd trezor-mcu
+```
 
-## How to build TREZOR emulator for Linux?
+Use the `build.sh` command to build the images.
 
-1. [Install Docker](https://docs.docker.com/engine/installation/)
-2. `git clone https://github.com/trezor/trezor-mcu.git`
-3. `cd trezor-mcu`
-4. `./build-emulator.sh TAG` (where TAG is v1.5.0 for example, if left blank the script builds latest commit in master branch)
+* to build bootloader 1.6.0 and firmware 1.7.0:
+  ```sh
+  ./build.sh bl1.6.0 v1.7.0
+  ```
+* to build latest firmware from master:
+  ```sh
+  ./build.sh
+  ```
+* to build the emulator from master:
+  ```sh
+  ./build.sh EMU
+  ```
+* to build the emulator for version 1.7.0:
+  ```sh
+  ./build.sh EMU v1.7.0
+  ```
 
-This creates binary file `build/trezor-emulator-TAG`, which can be run and works as a trezor emulator. (Use `TREZOR_OLED_SCALE` env. variable to make screen bigger.)
+Build results are stored in the `build/` directory. File `bootloader-<tag>.bin` represents
+the bootloader, `trezor-<tag>.bin` is the firmware image, and `trezor-emulator-<tag>.elf`
+is the emulator executable.
+
+You can use `TREZOR_OLED_SCALE` environment variable to make emulator screen bigger.
 
 ## How to get fingerprint of firmware signed and distributed by SatoshiLabs?
 
diff --git a/build-emulator.sh b/build-emulator.sh
deleted file mode 100755
index 40d5d28d46..0000000000
--- a/build-emulator.sh
+++ /dev/null
@@ -1,19 +0,0 @@
-#!/bin/bash
-set -e
-
-IMAGE=trezor-mcu-build-emulator64
-TAG=${1:-master}
-ELFFILE=build/trezor-emulator64-$TAG
-
-docker build -f Dockerfile.emulator -t $IMAGE .
-docker run -t -v $(pwd)/build:/build:z $IMAGE /bin/sh -c "\
-	git clone https://github.com/trezor/trezor-mcu && \
-	cd trezor-mcu && \
-	git checkout $TAG && \
-	git submodule update --init && \
-	make -C vendor/nanopb/generator/proto && \
-	make -C firmware/protob && \
-	EMULATOR=1 make && \
-	EMULATOR=1 make -C emulator && \
-	EMULATOR=1 make -C firmware && \
-	cp firmware/trezor.elf /$ELFFILE"
diff --git a/build.sh b/build.sh
index 81dc2a8dc5..6afb96c5da 100755
--- a/build.sh
+++ b/build.sh
@@ -1,11 +1,19 @@
 #!/bin/bash
 set -e
 
-IMAGE=trezor-mcu-build
-
 BOOTLOADER_COMMIT=${1:-HEAD}
 FIRMWARE_COMMIT=${2:-HEAD}
 
-docker build -t "$IMAGE" .
+if [ "$BOOTLOADER_COMMIT" = "EMU" ]; then
+  export EMULATOR=1
+fi
+
+if [ "$EMULATOR" = 1 ]; then
+  IMAGE=trezor-mcu-emulator
+else
+  IMAGE=trezor-mcu-build
+fi
+
+docker build -t "$IMAGE" --build-arg EMULATOR=$EMULATOR .
 docker run -it -v $(pwd):/src:z --user="$(stat -c "%u:%g" .)" "$IMAGE" \
   /src/script/fullbuild "$BOOTLOADER_COMMIT" "$FIRMWARE_COMMIT"
diff --git a/script/fullbuild b/script/fullbuild
index 520271fdc9..044ab94e63 100755
--- a/script/fullbuild
+++ b/script/fullbuild
@@ -22,6 +22,10 @@ readonly FIRMWARE_DIR="$BUILD_DIR/firmware"
 readonly FIRMWARE_FILENAME="firmware/trezor.bin"
 readonly FIRMWARE_PATH="$FIRMWARE_DIR/$FIRMWARE_FILENAME"
 
+readonly EMULATOR_DIR="$FIRMWARE_DIR"
+readonly EMULATOR_FILENAME="firmware/trezor-emulator.elf"
+readonly EMULATOR_PATH="$EMULATOR_DIR/firmware/trezor.elf"
+
 worktree_setup() {
     local path="$1"
     local commit="$2"
@@ -38,7 +42,21 @@ worktree_setup() {
 worktree_build() {
     local path="$1"
 
-    ( cd "$path" && pipenv install && pipenv run script/cibuild )
+    if [ -e "$path/Pipfile" ]; then
+        pushd $path
+        if ! pipenv install; then
+            # older tags can fail because they don't have protobuf in Pipfile
+            pipenv run pip install "protobuf==3.4.0"
+            pipenv install
+        fi
+        pipenv run script/cibuild
+        popd
+    else
+        # even older tags don't have Pipfile!
+        # use current one
+        pipenv install
+        ( cd "$path" && pipenv run script/cibuild )
+    fi
 }
 
 worktree_copy() {
@@ -67,28 +85,42 @@ main() {
     local firmware_commit="$2"
 
     script/bootstrap
-
-    worktree_setup "$BOOTLOADER_DIR" "$bootloader_commit"
-    worktree_build "$BOOTLOADER_DIR"
-
-    local bootloader_path="$(worktree_copy \
-        "$BOOTLOADER_DIR" \
-        "$BOOTLOADER_FILENAME" \
-        "bl*")"
-
     worktree_setup "$FIRMWARE_DIR" "$firmware_commit"
-    cp "$BOOTLOADER_PATH" "$FIRMWARE_DIR/$BOOTLOADER_FILENAME"
+
+    if [ "$EMULATOR" != 1 ]; then
+        worktree_setup "$BOOTLOADER_DIR" "$bootloader_commit"
+        worktree_build "$BOOTLOADER_DIR"
+
+        cp "$BOOTLOADER_PATH" "$FIRMWARE_DIR/$BOOTLOADER_FILENAME"
+    fi
+
     worktree_build "$FIRMWARE_DIR"
 
-    local firmware_path="$(worktree_copy \
-        "$FIRMWARE_DIR" \
-        "$FIRMWARE_FILENAME" \
-        "v*")"
+    if [ "$EMULATOR" = 1 ]; then
+        cp "$EMULATOR_PATH" "$EMULATOR_DIR/$EMULATOR_FILENAME"
+        local firmware_path="$(worktree_copy \
+            "$EMULATOR_DIR" \
+            "$EMULATOR_FILENAME" \
+            "v*")"
+        chmod +x "$firmware_path"
 
-    printf "\n\n"; $PYTHON script/fingerprint \
-        "$bootloader_path" \
-        --max-size 32768 \
-        --double
+    else
+
+        local firmware_path="$(worktree_copy \
+            "$FIRMWARE_DIR" \
+            "$FIRMWARE_FILENAME" \
+            "v*")"
+
+        local bootloader_path="$(worktree_copy \
+            "$BOOTLOADER_DIR" \
+            "$BOOTLOADER_FILENAME" \
+            "bl*")"
+
+        printf "\n\n"; $PYTHON script/fingerprint \
+            "$bootloader_path" \
+            --max-size 32768 \
+            --double
+    fi
 
     printf "\n\n"; $PYTHON script/fingerprint \
         "$firmware_path" \