diff --git a/tools/mccibootloader_image/README.md b/tools/mccibootloader_image/README.md
index ed42766..16ff102 100644
--- a/tools/mccibootloader_image/README.md
+++ b/tools/mccibootloader_image/README.md
@@ -70,6 +70,8 @@ The following options are defined. Note that options can be mixed with the input
 <dd>Update the input file in place.</dd>
 <dt><code>-k <em>file</em></code>, <code>--keyfile <em>file</em></code></dt>
 <dd>Read the signing key from <code><em>file</em></code>, which must be an OpenSSH ed25519 private key file, not password protected. The (insecure) keyfile <code>test/mcci-test.pem</code> is conventionally used for test purposes. </dd>
+<dt><code>-V <em>major[.minor[.patch]][-pre]</em></code>, <code>--app-version <em>major[.minor[.patch]][-pre]</em></code></dt>
+<dd>Set the application version according to the argument.</dd>
 <dt><code>-s</code>, <code>--sign</code></dt>
 <dd>Compute the hash (as with <code>-h</code>, and then sign. A key file must be provided.</dd>
 <dt><code>-v</code>, <code>--verbose</code></dt>
@@ -93,6 +95,7 @@ Program settings:
        --patch: false
      --keyfile: C:/mcci/projects/lora/bootloader/tools/mccibootloader_image/test/mcci-test.pem
      --comment: <<none>>
+ --app-version: <<none>>
 
 input:          build/arm-none-eabi/release/McciBootloader_46xx
 output:         build/arm-none-eabi/release/McciBootloader_46xx.elf
diff --git a/tools/mccibootloader_image/i/mccibootloader_image.h b/tools/mccibootloader_image/i/mccibootloader_image.h
index bbcfd77..4b41639 100644
--- a/tools/mccibootloader_image/i/mccibootloader_image.h
+++ b/tools/mccibootloader_image/i/mccibootloader_image.h
@@ -65,6 +65,49 @@ static_assert(offsetof(GuidWire_t, clock_seq_low) == 9, "GUID layout mismatch");
 static_assert(offsetof(GuidWire_t, node) == 10, "GUID layout mismatch");
 static_assert(sizeof(GuidWire_t) == GuidWire_t_SIZE, "GUID layout mismatch");
 
+/* versions */
+namespace McciVersion {
+	typedef std::uint32_t Version_t;
+
+	// create a version number for comparison
+	constexpr std::uint32_t
+	makeVersion(
+		std::uint8_t major, std::uint8_t minor, std::uint8_t patch, std::uint8_t local = 0
+		)
+		{
+		return ((std::uint32_t)major << 24u) | ((std::uint32_t)minor << 16u) | ((std::uint32_t)patch << 8u) | (std::uint32_t)local;
+		}
+
+	// extract major number from version
+	constexpr std::uint8_t
+	getMajor(std::uint32_t v)
+		{
+		return std::uint8_t(v >> 24u);
+		}
+
+	// extract minor number from version
+	constexpr std::uint8_t
+	getMinor(std::uint32_t v)
+		{
+		return std::uint8_t(v >> 16u);
+		}
+
+	// extract patch number from version
+	constexpr std::uint8_t
+		getPatch(std::uint32_t v)
+		{
+		return std::uint8_t(v >> 8u);
+		}
+
+	// extract local number from version
+	constexpr std::uint8_t
+	getLocal(std::uint32_t v)
+		{
+		return std::uint8_t(v);
+		}
+} // namespace McciVersion
+
+
 // a forward reference
 struct McciBootloader_AppInfo_Wire_t;
 
@@ -85,6 +128,8 @@ struct App_t
 	std::string	progname;
 	std::string	keyfilename;
 	std::vector<uint8_t>	fileimage;
+	McciVersion::Version_t	appVersion;
+	bool		fAppVersion;
 
 	struct AppElf_t
 		{
@@ -118,6 +163,7 @@ struct App_t
 	void readImage();
 	void writeImage();
 	void elfImagePrep();
+	void setAppVersion(const string &versionString);
 
 	Keyfile_ed25519_t keyfile;
 	};
@@ -134,47 +180,6 @@ static constexpr const char *filebasename(const char *s)
     return pName;
     }
 
-namespace McciVersion {
-	typedef std::uint32_t Version_t;
-
-	// create a version number for comparison
-	constexpr std::uint32_t
-	makeVersion(
-		std::uint8_t major, std::uint8_t minor, std::uint8_t patch, std::uint8_t local = 0
-		)
-		{
-		return ((std::uint32_t)major << 24u) | ((std::uint32_t)minor << 16u) | ((std::uint32_t)patch << 8u) | (std::uint32_t)local;
-		}
-
-	// extract major number from version
-	constexpr std::uint8_t
-	getMajor(std::uint32_t v)
-		{
-		return std::uint8_t(v >> 24u);
-		}
-
-	// extract minor number from version
-	constexpr std::uint8_t
-	getMinor(std::uint32_t v)
-		{
-		return std::uint8_t(v >> 16u);
-		}
-
-	// extract patch number from version
-	constexpr std::uint8_t
-		getPatch(std::uint32_t v)
-		{
-		return std::uint8_t(v >> 8u);
-		}
-
-	// extract local number from version
-	constexpr std::uint8_t
-	getLocal(std::uint32_t v)
-		{
-		return std::uint8_t(v);
-		}
-} // namespace McciVersion
-
 // the layout of the image
 class uint32_le_t
 	{
diff --git a/tools/mccibootloader_image/i/mccibootloader_image_version.h b/tools/mccibootloader_image/i/mccibootloader_image_version.h
index f3a9bcf..0ee9346 100644
--- a/tools/mccibootloader_image/i/mccibootloader_image_version.h
+++ b/tools/mccibootloader_image/i/mccibootloader_image_version.h
@@ -27,7 +27,7 @@ Copyright and License:
 #include "mccibootloader_image.h"
 
 constexpr McciVersion::Version_t kVersion =
-	McciVersion::makeVersion(0, 3, 1, 0);
+	McciVersion::makeVersion(0, 4, 0, 0);
 constexpr char kCopyright[] = "Copyright (C) 2021, MCCI Corporation";
 
 #endif /* _mccibootloader_image_version_h_ */
diff --git a/tools/mccibootloader_image/src/image.cpp b/tools/mccibootloader_image/src/image.cpp
index 35ff932..686e438 100644
--- a/tools/mccibootloader_image/src/image.cpp
+++ b/tools/mccibootloader_image/src/image.cpp
@@ -107,11 +107,30 @@ void App_t::readImage()
 		{
 		this->fatal("unexpected e_phoff value");
 		}
-	if (pElfIdent32->getPhnum() > 4)
+
+	// display the program header entries
+	if (this->fVerbose)
 		{
-		ostringstream msg;
-		msg << "ELF e_phnum > 4: " << pElfIdent32->getPhnum();
-		this->fatal(msg.str());
+		for (unsigned i = 0; i < pElfIdent32->getPhnum(); ++i)
+			{
+			const ElfIdent32_t::ProgramHeader_t ph { *pElfIdent32, i };
+
+			// dump the section
+				{
+				std::ostringstream msg;
+
+				msg << "ELF: section " << i << ": "
+				<< "vaddr(" << std::hex << ph.getVaddr() << ") "
+				<< "paddr(" << std::hex << ph.getPaddr() << ") "
+				<< "size(" << std::hex << ph.getMemsz() << ") "
+				<< "vend(" << std::hex << ph.getVaddr() + ph.getMemsz() << ") "
+				<< "offset(" << std::hex << ph.getOffset() << ") "
+				<< "fsize(" << std::hex << ph.getFilesz() << ") "
+				<< "flags(" << std::hex << ph.getFlags() << ")"
+				;
+				this->verbose(msg.str());
+				}
+			}
 		}
 
 	// empty the file image and set up the elf image
@@ -129,23 +148,6 @@ void App_t::readImage()
 		if (ph.getType() != decltype(ph.getType())::kLoad)
 			this->fatal("section type is not loadable");
 
-		// dump the section
-		if (this->fVerbose)
-			{
-			std::ostringstream msg;
-
-			msg << "ELF: section " << i << ": "
-			    << "vaddr(" << std::hex << ph.getVaddr() << ") "
-			    << "paddr(" << std::hex << ph.getPaddr() << ") "
-			    << "size(" << std::hex << ph.getMemsz() << ") "
-			    << "vend(" << std::hex << ph.getVaddr() + ph.getMemsz() << ") "
-			    << "offset(" << std::hex << ph.getOffset() << ") "
-			    << "fsize(" << std::hex << ph.getFilesz() << ") "
-			    << "flags(" << std::hex << ph.getFlags() << ")"
-			    ;
-			this->verbose(msg.str());
-			}
-
 		// we used to try skipping writable sections, but ...
 		// that requires PHDRS in the link script. Instead, use
 		// a heuristic to discard non-contiguous sections
diff --git a/tools/mccibootloader_image/src/main.cpp b/tools/mccibootloader_image/src/main.cpp
index ea14cb1..2ca6534 100644
--- a/tools/mccibootloader_image/src/main.cpp
+++ b/tools/mccibootloader_image/src/main.cpp
@@ -35,6 +35,10 @@ static void dumpAppInfo(
 	McciBootloader_AppInfo_Wire_t const &appInfo
 	);
 
+static std::string versionToString(
+	McciVersion::Version_t version
+	);
+
 /****************************************************************************\
 |
 |	Read-only data.
@@ -196,6 +200,13 @@ void App_t::scanArgs(int argc, char **argv)
 				this->usage("missing comment value");
 			this->pComment = *argv++;
 			}
+		else if (arg == "-V" || arg == "--app-version")
+			{
+			if (*argv == nullptr)
+				this->usage("missing app-version value");
+
+			this->setAppVersion(string(*argv));
+			}
 		else if (arg == "--version")
 			{
 			std::cout << "mccibootloader_image v"
@@ -257,6 +268,7 @@ void App_t::scanArgs(int argc, char **argv)
 			  << "       --patch: " << this->fPatch << "\n"
 		          << "     --keyfile: " << this->keyfilename << "\n"
 			  << "     --comment: " << (pComment == NULL ? "<<none>>": pComment) << "\n"
+			  << " --app-version: " << (!this->fAppVersion ? "<<none>>": versionToString(this->appVersion)) << "\n"
 			  << "\n"
 		          << "input:          " << this->infilename << "\n"
 		          << "output:         "
@@ -271,17 +283,119 @@ void App_t::scanArgs(int argc, char **argv)
 void App_t::usage(const string &message)
 	{
 	string usage = message;
-	if (usage != "")
+	if (usage != "" && usage[usage.length() - 1] != '\n')
 		{
 		usage.append(": ");
 		}
 	usage.append("usage: ");
 	usage.append(this->progname);
-	usage.append(" -[vsh k{keyfile} c{comment}] --[version sign hash comment {comment} dry-run add-time force-binary] infile [outfile]\n");
+	usage.append(" -[vsh k{keyfile} c{comment} -V{app-version}] --[version sign hash app-version {version} comment {comment} dry-run add-time force-binary] infile [outfile]\n");
 	fprintf(stderr, "%s\n", usage.c_str());
 	exit(EXIT_FAILURE);
 	}
 
+static std::string versionToString(McciVersion::Version_t version)
+	{
+	ostringstream sVersion;
+	sVersion << unsigned(McciVersion::getMajor(version))
+		 << "."
+		 << unsigned(McciVersion::getMinor(version))
+		 << "."
+		 << unsigned(McciVersion::getPatch(version))
+		 ;
+	if (McciVersion::getLocal(version) != 0)
+		{
+		sVersion << "-"
+			 << unsigned(McciVersion::getLocal(version));
+		}
+
+	return sVersion.str();
+	}
+
+void App_t::setAppVersion(
+	const string &versionString
+	)
+	{
+	unsigned i = 0;
+
+	auto const failstring = [&versionString, &i](const string &message) -> string
+		{
+		string result;
+		result = message + ": ";
+		result += versionString.substr(0, i);
+		result += "[";
+		result += versionString.substr(i);
+		result += "]\n";
+		return result;
+		};
+
+	auto const getn = [this, &versionString, &i, &failstring]() -> std::uint8_t
+		{
+		std::uint32_t result;
+		auto const n = versionString.length();
+		bool err;
+		bool gotDigit;
+
+		err = false;
+		gotDigit = false;
+		result = 0;
+
+		while (i < n && !err)
+			{
+			auto c = versionString[i];
+			if (! ('0' <= c && c <= '9'))
+				break;
+
+			gotDigit = true;
+			result = result * 10 + (c - '0');
+			if (result >= 256)
+				err = true;
+			else
+				++i;
+			}
+
+		if (! gotDigit)
+			err = true;
+
+		if (err)
+			this->usage(failstring("illegal app-version syntax"));
+
+		return result;
+		};
+	auto const checkpunct = [&versionString, &i](char c) -> bool
+		{
+		auto const n = versionString.length();
+
+		if (i < n && versionString[i] == c)
+			{
+			++i;
+			return true;
+			}
+		return false;
+		};
+
+	auto const major = getn();
+	std::uint8_t minor, patch, prerelease;
+	minor = patch = prerelease = 0;
+
+	if (checkpunct('.'))
+		{
+		minor = getn();
+		if (checkpunct('.'))
+			patch = getn();
+		}
+	if (checkpunct('-'))
+		{
+		prerelease = getn();
+		}
+
+	if (i < versionString.length())
+		this->usage(failstring("illegal value for app-version"));
+
+	this->appVersion = McciVersion::makeVersion(major, minor, patch, prerelease);
+	this->fAppVersion = true;
+	}
+
 void dumpAppInfo(
 	std::string const &s,
 	McciBootloader_AppInfo_Wire_t const &appInfo
@@ -296,21 +410,8 @@ void dumpAppInfo(
 	          << " posixTimestamp: " << std::setw(16) << std::setfill(' ') << appInfo.posixTimestamp.get() << "\n"
 		  << "        comment:         " << appInfo.comment.get() << "\n";
 		  ;
-	auto version = appInfo.version.get();
-	ostringstream sVersion;
-	sVersion << unsigned(McciVersion::getMajor(version))
-		 << "."
-		 << unsigned(McciVersion::getMinor(version))
-		 << "."
-		 << unsigned(McciVersion::getPatch(version))
-		 ;
-	if (McciVersion::getLocal(version) != 0)
-		{
-		sVersion << "-"
-			 << unsigned(McciVersion::getLocal(version));
-		}
   
-	std::cout << "        version: " << std::setw(16) << std::setfill(' ') << sVersion.str();
+	std::cout << "        version: " << std::setw(16) << std::setfill(' ') << versionToString(appInfo.version.get());
 	std::cout << "\n";
 	std::cout << "\n";
 	}
@@ -384,6 +485,12 @@ void App_t::addHeader()
 		this->authSize
 		);
 
+	// set the version if one was provided
+	if (this->fAppVersion)
+		appInfo.version.put(
+			this->appVersion
+			);
+
 	// add posix time
 	if (this->fAddTime)
 		{