diff --git a/Makefile b/Makefile
index 8ff927f22..0c3aef79d 100644
--- a/Makefile
+++ b/Makefile
@@ -28,15 +28,11 @@ vendorheader: ## construct default vendor header
 	./tools/build_vendorheader 'db995fe25169d141cab9bbba92baa01f9f2e1ece7df4cb2ac05190f37fcc1f9d:2152f8d19b791d24453242e15f2eab6cb7cffa7b6a5ed30097960e069881db12:22fc297792f0b6ffc0bfcfdb7edb0c0aa14e025a365ec0e342e86e3829cb74b6' 1 0.0 SatoshiLabs assets/satoshilabs_120.toif micropython/firmware/vendorheader.bin
 	./tools/binctl micropython/firmware/vendorheader.bin -s
 
-binctl:
+binctl: ## print info about binary files
 	./tools/binctl micropython/loader/build/loader.bin
 	./tools/binctl micropython/firmware/vendorheader.bin
 	./tools/binctl micropython/firmware/build/firmware.bin
 
-sign:
-	./tools/binctl micropython/loader/build/loader.bin -s
-	./tools/binctl micropython/firmware/build/firmware.bin -s
-
 ## emulator commands:
 
 run: ## run unix port
@@ -62,9 +58,11 @@ build_bootloader: ## build bootloader
 
 build_loader: ## build loader
 	$(MAKE) -f Makefile.loader $(TREZORHAL_PORT_OPTS)
+	./tools/binctl micropython/loader/build/loader.bin -s
 
 build_firmware: res build_cross ## build firmware with frozen modules
 	$(MAKE) -f Makefile.firmware $(TREZORHAL_PORT_OPTS)
+	./tools/binctl micropython/firmware/build/firmware.bin -s
 
 build_unix: ## build unix port
 	$(MAKE) -f ../../../micropython/unix/Makefile -C vendor/micropython/unix $(UNIX_PORT_OPTS)
diff --git a/tools/binctl b/tools/binctl
index 66af5181b..c96b4ef09 100755
--- a/tools/binctl
+++ b/tools/binctl
@@ -22,6 +22,11 @@ def get_sig(data):
     return sigmask, sig
 
 
+def format_sigmask(sigmask):
+    bits = [ str(b + 1) if sigmask & (1<<b) else '.' for b in range(8) ]
+    return '0x%02x = [%s]' % (sigmask, ' '.join(bits))
+
+
 # loader/firmware headers specification: https://github.com/trezor/trezor-core/blob/master/docs/bootloader.md
 
 
@@ -64,7 +69,7 @@ class BinImage:
         print('  * expiry  :', self.expiry)
         print('  * codelen :', self.codelen)
         print('  * version : %d.%d.%d.%d' % (self.vmajor, self.vminor, self.vpatch, self.vbuild))
-        print('  * sigmask :', self.sigmask)
+        print('  * sigmask :', format_sigmask(self.sigmask))
         print('  * sig     :', binascii.hexlify(self.sig).decode('ascii'))
         print('  * total   : %d bytes' % total_len)
         print()
@@ -160,7 +165,7 @@ class VendorHeader:
             print('  * vpub #%d :' % (i + 1), binascii.hexlify(self.vpub[i]).decode('ascii'))
         print('  * vstr    :', self.vstr.decode('ascii'))
         print('  * vimg    : (%d bytes)' % len(self.vimg))
-        print('  * sigmask :', self.sigmask)
+        print('  * sigmask :', format_sigmask(self.sigmask))
         print('  * sig     :', binascii.hexlify(self.sig).decode('ascii'))
 
     def serialize_header(self, sig=True):