diff --git a/gnu/local.mk b/gnu/local.mk
index 5ba5af94a6..0a81e0fe75 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -1573,7 +1573,15 @@ dist_patch_DATA =						\
   %D%/packages/patches/openjdk-9-module-reproducibility.patch	\
   %D%/packages/patches/openjdk-9-module2-reproducibility.patch	\
   %D%/packages/patches/openjdk-9-module3-reproducibility.patch	\
+  %D%/packages/patches/openjdk-10-char-reproducibility.patch	\
+  %D%/packages/patches/openjdk-10-classlist-reproducibility.patch	\
+  %D%/packages/patches/openjdk-10-corba-reproducibility.patch	\
   %D%/packages/patches/openjdk-10-idlj-reproducibility.patch	\
+  %D%/packages/patches/openjdk-10-jar-reproducibility.patch	\
+  %D%/packages/patches/openjdk-10-jtask-reproducibility.patch	\
+  %D%/packages/patches/openjdk-10-module-reproducibility.patch	\
+  %D%/packages/patches/openjdk-10-module3-reproducibility.patch	\
+  %D%/packages/patches/openjdk-10-module4-reproducibility.patch	\
   %D%/packages/patches/openjdk-15-xcursor-no-dynamic.patch	\
   %D%/packages/patches/openmpi-mtl-priorities.patch		\
   %D%/packages/patches/openssh-hurd.patch			\
diff --git a/gnu/packages/java.scm b/gnu/packages/java.scm
index 3d36849f7d..37b310141e 100644
--- a/gnu/packages/java.scm
+++ b/gnu/packages/java.scm
@@ -1763,7 +1763,15 @@ (define-public openjdk10
                (base32
                 "0zywq2203b4hx4jms9vbwvjcj1d3k2v3qpx4s33729fkpmid97r4"))
               (patches (search-patches
-                        "openjdk-10-idlj-reproducibility.patch"))
+                        "openjdk-10-module-reproducibility.patch"
+                        "openjdk-10-module3-reproducibility.patch"
+                        "openjdk-10-module4-reproducibility.patch"
+                        "openjdk-10-char-reproducibility.patch"
+                        "openjdk-10-classlist-reproducibility.patch"
+                        "openjdk-10-corba-reproducibility.patch"
+                        "openjdk-10-idlj-reproducibility.patch"
+                        "openjdk-10-jar-reproducibility.patch"
+                        "openjdk-10-jtask-reproducibility.patch"))
               (modules '((guix build utils)))
               (snippet
                `(begin
@@ -1780,6 +1788,11 @@ (define-public openjdk10
                (substitute* "make/data/blacklistedcertsconverter/blacklisted.certs.pem"
                  (("^#!.*") "#! java BlacklistedCertsConverter SHA-256\n"))
                #t))
+           (add-after 'unpack 'remove-timestamping
+             (lambda _
+               (substitute* "./src/hotspot/share/runtime/vm_version.cpp"
+                 (("__DATE__") "")
+                 (("__TIME__") ""))))
            (replace 'configure
              (lambda* (#:key inputs outputs #:allow-other-keys)
                (invoke "bash" "./configure"
diff --git a/gnu/packages/patches/openjdk-10-char-reproducibility.patch b/gnu/packages/patches/openjdk-10-char-reproducibility.patch
new file mode 100644
index 0000000000..a7932678af
--- /dev/null
+++ b/gnu/packages/patches/openjdk-10-char-reproducibility.patch
@@ -0,0 +1,12 @@
+Danny
+--- orig/jdk-6fa770f9f8ab/make/jdk/src/classes/build/tools/generatecharacter/GenerateCharacter.java	2022-04-13 19:24:10.211683257 +0200
++++ jdk-6fa770f9f8ab/make/jdk/src/classes/build/tools/generatecharacter/GenerateCharacter.java	2022-04-13 22:51:50.680487330 +0200
+@@ -693,7 +693,7 @@
+         PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter(theOutputFileName)));
+         out.println(commentStart +
+             " This file was generated AUTOMATICALLY from a template file " +
+-            new java.util.Date() + commentEnd);
++            (System.getenv("SOURCE_DATE_EPOCH") == null ? new java.util.Date() : new java.util.Date(1000 * Long.parseLong(System.getenv("SOURCE_DATE_EPOCH")))) + commentEnd);
+         int marklen = commandMarker.length();
+         LOOP: while(true) {
+             try {
diff --git a/gnu/packages/patches/openjdk-10-classlist-reproducibility.patch b/gnu/packages/patches/openjdk-10-classlist-reproducibility.patch
new file mode 100644
index 0000000000..e1292ba82d
--- /dev/null
+++ b/gnu/packages/patches/openjdk-10-classlist-reproducibility.patch
@@ -0,0 +1,27 @@
+--- orig/jdk-6fa770f9f8ab/make/GenerateLinkOptData.gmk	2022-04-04 17:16:29.365930149 +0200
++++ jdk-6fa770f9f8ab/make/GenerateLinkOptData.gmk	2022-04-04 17:16:54.954624358 +0200
+@@ -61,11 +61,12 @@
+ 	$(call MakeDir, $(LINK_OPT_DIR))
+ 	$(call LogInfo, Generating $(patsubst $(OUTPUTDIR)/%, %, $@))
+ 	$(call LogInfo, Generating $(patsubst $(OUTPUTDIR)/%, %, $(JLI_TRACE_FILE)))
+-	$(FIXPATH) $(INTERIM_IMAGE_DIR)/bin/java -XX:DumpLoadedClassList=$@ \
++	$(FIXPATH) $(INTERIM_IMAGE_DIR)/bin/java -XX:DumpLoadedClassList=$@.tmp \
+ 	    -Djava.lang.invoke.MethodHandle.TRACE_RESOLVE=true \
+ 	    -cp $(SUPPORT_OUTPUTDIR)/classlist.jar \
+ 	    build.tools.classlist.HelloClasslist \
+ 	    $(LOG_DEBUG) 2>&1 > $(JLI_TRACE_FILE)
++	sort $@.tmp > $@
+ 
+ # The jli trace is created by the same recipe as classlist. By declaring these
+ # dependencies, make will correctly rebuild both jli trace and classlist
+--- orig/jdk-6fa770f9f8ab/make/gendata/Gendata-jdk.compiler.gmk	2022-04-13 19:24:10.191682716 +0200
++++ jdk-6fa770f9f8ab/make/gendata/Gendata-jdk.compiler.gmk	2022-04-13 20:58:57.891368216 +0200
+@@ -83,6 +83,8 @@
+ 	    $(CT_MODULESOURCEPATH) \
+ 	    $(CT_MODULES) \
+ 	    >$(@D)/A/system-modules
++	# Make files reproducible
++	find $(@D) -exec $(TOUCH) -h -c -t 197001010000.01 {} \;
+ 	$(TOUCH) $@
+ 
+ # Can't generate ct.sym directly into modules libs as the SetupJarArchive macro
diff --git a/gnu/packages/patches/openjdk-10-corba-reproducibility.patch b/gnu/packages/patches/openjdk-10-corba-reproducibility.patch
new file mode 100644
index 0000000000..bd5ce1fd2b
--- /dev/null
+++ b/gnu/packages/patches/openjdk-10-corba-reproducibility.patch
@@ -0,0 +1,12 @@
+Danny
+--- orig/jdk-6fa770f9f8ab/make/corba/src/classes/build/tools/logutil/MC.java	2022-04-13 19:24:10.111680549 +0200
++++ jdk-6fa770f9f8ab/make/corba/src/classes/build/tools/logutil/MC.java	2022-04-13 22:51:13.399462259 +0200
+@@ -154,7 +154,7 @@
+                   groupName);
+     pw.println("//");
+     pw.printMsg("// Generated by MC.java version @, DO NOT EDIT BY HAND!", VERSION);
+-    pw.printMsg("// Generated from input file @ on @", inFile, new Date());
++    pw.printMsg("// Generated from input file @ on @", inFile, System.getenv("SOURCE_DATE_EPOCH") == null ? new Date() : new Date(1000 * Long.parseLong(System.getenv("SOURCE_DATE_EPOCH"))));
+     pw.println();
+   }
+ 
diff --git a/gnu/packages/patches/openjdk-10-jar-reproducibility.patch b/gnu/packages/patches/openjdk-10-jar-reproducibility.patch
new file mode 100644
index 0000000000..176eedfce6
--- /dev/null
+++ b/gnu/packages/patches/openjdk-10-jar-reproducibility.patch
@@ -0,0 +1,103 @@
+diff -ru orig/jdk-6fa770f9f8ab/make/common/JarArchive.gmk jdk-6fa770f9f8ab/make/common/JarArchive.gmk
+--- orig/jdk-6fa770f9f8ab/make/common/JarArchive.gmk	2022-04-13 19:24:10.107680441 +0200
++++ jdk-6fa770f9f8ab/make/common/JarArchive.gmk	2022-04-13 19:31:18.031271019 +0200
+@@ -251,12 +251,14 @@
+ 	    $(ECHO) "Main-Class: $$(strip $$($1_JARMAIN))" >> $$($1_MANIFEST_FILE) $$(NEWLINE)) \
+ 	  $$(if $$($1_EXTRA_MANIFEST_ATTR), \
+ 	    $(PRINTF) "$$($1_EXTRA_MANIFEST_ATTR)\n" >> $$($1_MANIFEST_FILE) $$(NEWLINE)) \
++	  $(TOUCH) -h -c -t 197001010000.00 $$($1_MANIFEST_FILE) $$(NEWLINE) \
+ 	  $(ECHO) Creating $$($1_NAME) $$(NEWLINE) \
+ 	  $$($1_JAR_CMD) $$($1_JAR_CREATE_OPTIONS) $$@ $$($1_MANIFEST_FILE) $$(NEWLINE) \
+ 	  $$($1_SCAPTURE_CONTENTS) \
+ 	  $$($1_SCAPTURE_METAINF) \
+ 	  $$($1_SUPDATE_CONTENTS) \
+-	  $$($1_JARINDEX) && true \
++	  $$($1_JARINDEX) && true $$(NEWLINE) \
++	  d="`mktemp -d`" && $(CP) -f $$@ "$$$$d/a.jar" && (cd "$$$$d" && unzip a.jar META-INF/MANIFEST.MF && $(TOUCH) -h -c -t 197001010000.00 META-INF &&  $(TOUCH) -h -c -t 197001010000.00 META-INF/MANIFEST.MF && (zip --symlinks -0 -X a.jar META-INF META-INF/MANIFEST.MF; zip --symlinks -0 -X a.jar META-INF META-INF/MANIFEST.MF)) && $(CP) -f "$$$$d/a.jar" $$@ \
+ 	, \
+ 	  $(ECHO) Modifying $$($1_NAME) $$(NEWLINE) \
+ 	  $$($1_CAPTURE_CONTENTS) \
+diff -ru orig/jdk-6fa770f9f8ab/make/JrtfsJar.gmk jdk-6fa770f9f8ab/make/JrtfsJar.gmk
+--- orig/jdk-6fa770f9f8ab/make/JrtfsJar.gmk	2022-04-13 19:24:10.091680007 +0200
++++ jdk-6fa770f9f8ab/make/JrtfsJar.gmk	2022-04-13 19:29:30.044346222 +0200
+@@ -57,13 +57,18 @@
+ # file will not be copied unless META-INF/services would also be added to the INCLUDES.
+ # Adding META-INF/services would include all files in that directory when only the one
+ # is needed, which is why this explicit copy is defined instead.
+-$(eval $(call SetupCopyFiles, COPY_JIMAGE_SERVICE_PROVIDER, \
++$(eval $(call SetupCopyFiles, COPY_JIMAGE_SERVICE_PROVIDER, \
+     SRC := $(TOPDIR)/src/java.base/share/classes, \
+     DEST := $(SUPPORT_OUTPUTDIR)/jrtfs_classes, \
+     FILES := META-INF/services/java.nio.file.spi.FileSystemProvider))
+ 
++.PHONY: $(COPY_JIMAGE_SERVICE_PROVIDER)_fix
++$(COPY_JIMAGE_SERVICE_PROVIDER)_fix: $(COPY_JIMAGE_SERVICE_PROVIDER)
++	find $(SUPPORT_OUTPUTDIR)/jrtfs_classes -exec $(TOUCH) -h -c -t 197001010000.00 {} \;
++	$(TOUCH) -h -c -t 197001010000.00 $(SUPPORT_OUTPUTDIR)/java-main-manifest.mf
++
+ $(eval $(call SetupJarArchive,BUILD_JRTFS_JAR, \
+-    DEPENDENCIES := $(BUILD_JRTFS) $(COPY_JIMAGE_SERVICE_PROVIDER), \
++    DEPENDENCIES := $(BUILD_JRTFS) $(COPY_JIMAGE_SERVICE_PROVIDER)_fix, \
+     SRCS := $(SUPPORT_OUTPUTDIR)/jrtfs_classes, \
+     JAR := $(SUPPORT_OUTPUTDIR)/modules_libs/java.base/jrt-fs.jar, \
+     MANIFEST := $(SUPPORT_OUTPUTDIR)/java-main-manifest.mf, \
+diff -ru orig/jdk-6fa770f9f8ab/src/jdk.jartool/share/classes/sun/tools/jar/Main.java jdk-6fa770f9f8ab/src/jdk.jartool/share/classes/sun/tools/jar/Main.java
+--- orig/jdk-6fa770f9f8ab/src/jdk.jartool/share/classes/sun/tools/jar/Main.java	2022-04-13 19:24:12.555746751 +0200
++++ jdk-6fa770f9f8ab/src/jdk.jartool/share/classes/sun/tools/jar/Main.java	2022-04-13 19:25:34.117955999 +0200
+@@ -849,12 +849,18 @@
+                     output(getMsg("out.added.manifest"));
+                 }
+                 ZipEntry e = new ZipEntry(MANIFEST_DIR);
+-                e.setTime(System.currentTimeMillis());
++                if (System.getenv("SOURCE_DATE_EPOCH") != null)
++                    e.setTime(1000 * Long.parseLong(System.getenv("SOURCE_DATE_EPOCH")));
++                else
++                    e.setTime(System.currentTimeMillis());
+                 e.setSize(0);
+                 e.setCrc(0);
+                 zos.putNextEntry(e);
+                 e = new ZipEntry(MANIFEST_NAME);
+-                e.setTime(System.currentTimeMillis());
++                if (System.getenv("SOURCE_DATE_EPOCH") != null)
++                    e.setTime(1000 * Long.parseLong(System.getenv("SOURCE_DATE_EPOCH")));
++                else
++                    e.setTime(System.currentTimeMillis());
+                 if (flag0) {
+                     crc32Manifest(e, manifest);
+                 }
+@@ -1021,7 +1027,10 @@
+         throws IOException
+     {
+         ZipEntry e = new ZipEntry(INDEX_NAME);
+-        e.setTime(System.currentTimeMillis());
++        if (System.getenv("SOURCE_DATE_EPOCH") != null)
++            e.setTime(1000 * Long.parseLong(System.getenv("SOURCE_DATE_EPOCH")));
++        else
++            e.setTime(System.currentTimeMillis());
+         if (flag0) {
+             CRC32OutputStream os = new CRC32OutputStream();
+             index.write(os);
+@@ -1040,7 +1049,10 @@
+             String name = mi.getKey();
+             byte[] bytes = mi.getValue();
+             ZipEntry e = new ZipEntry(name);
+-            e.setTime(System.currentTimeMillis());
++            if (System.getenv("SOURCE_DATE_EPOCH") != null)
++                e.setTime(1000 * Long.parseLong(System.getenv("SOURCE_DATE_EPOCH")));
++            else
++                e.setTime(System.currentTimeMillis());
+             if (flag0) {
+                 crc32ModuleInfo(e, bytes);
+             }
+@@ -1065,7 +1077,10 @@
+             addMultiRelease(m);
+         }
+         ZipEntry e = new ZipEntry(MANIFEST_NAME);
+-        e.setTime(System.currentTimeMillis());
++        if (System.getenv("SOURCE_DATE_EPOCH") != null)
++            e.setTime(1000 * Long.parseLong(System.getenv("SOURCE_DATE_EPOCH")));
++        else
++            e.setTime(System.currentTimeMillis());
+         if (flag0) {
+             crc32Manifest(e, m);
+         }
diff --git a/gnu/packages/patches/openjdk-10-jtask-reproducibility.patch b/gnu/packages/patches/openjdk-10-jtask-reproducibility.patch
new file mode 100644
index 0000000000..3411ca12ae
--- /dev/null
+++ b/gnu/packages/patches/openjdk-10-jtask-reproducibility.patch
@@ -0,0 +1,53 @@
+--- jdk-10/src/jdk.jlink/share/classes/jdk/tools/jmod/JmodTask.java.orig	2022-04-04 11:18:52.760626467 +0200
++++ jdk-10/src/jdk.jlink/share/classes/jdk/tools/jmod/JmodTask.java	2022-04-04 12:03:40.645325687 +0200
+@@ -105,6 +105,7 @@
+ import jdk.internal.module.ModuleTarget;
+ import jdk.internal.module.Resources;
+ import jdk.tools.jlink.internal.Utils;
++import java.util.TreeSet;
+ 
+ import static java.util.stream.Collectors.joining;
+ 
+@@ -768,6 +769,7 @@
+         void processSection(JmodOutputStream out, Section section, Path path)
+             throws IOException
+         {
++            TreeSet<Path> paths = new TreeSet<>();
+             Files.walkFileTree(path, Set.of(FileVisitOption.FOLLOW_LINKS),
+                 Integer.MAX_VALUE, new SimpleFileVisitor<Path>() {
+                     @Override
+@@ -781,20 +783,24 @@
+ 
+                         if (!relPath.toString().equals(MODULE_INFO)
+                                 && !matches(relPath, excludes)) {
+-                            try (InputStream in = Files.newInputStream(file)) {
+-                                out.writeEntry(in, section, relPath.toString());
+-                            } catch (IOException x) {
+-                                if (x.getMessage().contains("duplicate entry")) {
+-                                    warning("warn.ignore.duplicate.entry",
+-                                            relPath.toString(), section);
+-                                    return FileVisitResult.CONTINUE;
+-                                }
+-                                throw x;
+-                            }
++                            paths.add(file);
+                         }
+                         return FileVisitResult.CONTINUE;
+                     }
+                 });
++            for (Path file : paths) {
++                Path relPath = path.relativize(file);
++                try (InputStream in = Files.newInputStream(file)) {
++                    out.writeEntry(in, section, relPath.toString());
++                } catch (IOException x) {
++                    if (x.getMessage().contains("duplicate entry")) {
++                        warning("warn.ignore.duplicate.entry",
++                                  relPath.toString(), section);
++                        continue;
++                    }
++                    throw x;
++                }
++            }
+         }
+ 
+         boolean matches(Path path, List<PathMatcher> matchers) {
diff --git a/gnu/packages/patches/openjdk-10-module-reproducibility.patch b/gnu/packages/patches/openjdk-10-module-reproducibility.patch
new file mode 100644
index 0000000000..165edd3b4a
--- /dev/null
+++ b/gnu/packages/patches/openjdk-10-module-reproducibility.patch
@@ -0,0 +1,305 @@
+From a52c4ef44c0553a399a8a47e528db92e3bf51c6c Mon Sep 17 00:00:00 2001
+From: Alan Bateman <alanb@openjdk.org>
+Date: Wed, 29 Apr 2020 08:38:28 +0100
+Subject: [PATCH] 8243666: ModuleHashes attribute generated for JMOD and JAR
+ files depends on timestamps
+
+Reviewed-by: mchung
+---
+
+--- orig/jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleHashesBuilder.java	2022-04-13 19:24:10.655695284 +0200
++++ jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleHashesBuilder.java	2022-04-14 02:43:48.610326492 +0200
+@@ -27,9 +27,8 @@
+ 
+ import java.io.PrintStream;
+ import java.lang.module.Configuration;
++import java.lang.module.ModuleReference;
+ import java.lang.module.ResolvedModule;
+-import java.net.URI;
+-import java.nio.file.Path;
+ import java.nio.file.Paths;
+ import java.util.ArrayDeque;
+ import java.util.Collections;
+@@ -39,8 +38,8 @@
+ import java.util.LinkedList;
+ import java.util.Map;
+ import java.util.Set;
++import java.util.TreeMap;
+ import java.util.function.Consumer;
+-import java.util.function.Function;
+ import java.util.stream.Stream;
+ import static java.util.stream.Collectors.*;
+ 
+@@ -101,7 +100,7 @@
+         // the modules to record the hashes - it is the first matching
+         // module and has not been hashed during the traversal.
+         Set<String> mods = new HashSet<>();
+-        Map<String, ModuleHashes> hashes = new HashMap<>();
++        Map<String, ModuleHashes> hashes = new TreeMap<>();
+         builder.build()
+                .orderedNodes()
+                .filter(mn -> roots.contains(mn) && !mods.contains(mn))
+@@ -116,27 +115,17 @@
+                    mods.addAll(ns);
+ 
+                    if (!ns.isEmpty()) {
+-                       Map<String, Path> moduleToPath = ns.stream()
+-                           .collect(toMap(Function.identity(), this::moduleToPath));
+-                       hashes.put(mn, ModuleHashes.generate(moduleToPath, "SHA-256"));
++                       Set<ModuleReference> mrefs = ns.stream()
++                               .map(name -> configuration.findModule(name)
++                                                         .orElseThrow(InternalError::new))
++                               .map(ResolvedModule::reference)
++                               .collect(toSet());
++                       hashes.put(mn, ModuleHashes.generate(mrefs, "SHA-256"));
+                    }
+                });
+         return hashes;
+     }
+ 
+-    private Path moduleToPath(String name) {
+-        ResolvedModule rm = configuration.findModule(name).orElseThrow(
+-            () -> new InternalError("Selected module " + name + " not on module path"));
+-
+-        URI uri = rm.reference().location().get();
+-        Path path = Paths.get(uri);
+-        String fn = path.getFileName().toString();
+-        if (!fn.endsWith(".jar") && !fn.endsWith(".jmod")) {
+-            throw new UnsupportedOperationException(path + " is not a modular JAR or jmod file");
+-        }
+-        return path;
+-    }
+-
+     /*
+      * Utility class
+      */diff -ru orig/jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleHashes.java jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleHashes.java
+--- orig/jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleHashes.java	1970-01-01 01:00:01.000000000 +0100
++++ jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleHashes.java	2022-04-12 16:58:05.639985936 +0200
+@@ -26,17 +26,21 @@
+ package jdk.internal.module;
+ 
+ import java.io.IOException;
++import java.io.InputStream;
+ import java.io.UncheckedIOException;
+-import java.nio.ByteBuffer;
+-import java.nio.channels.FileChannel;
+-import java.nio.file.Path;
++import java.lang.module.ModuleReader;
++import java.lang.module.ModuleReference;
++import java.nio.charset.StandardCharsets;
+ import java.security.MessageDigest;
+ import java.security.NoSuchAlgorithmException;
++import java.util.Arrays;
+ import java.util.Collections;
+ import java.util.HashMap;
+ import java.util.Map;
+ import java.util.Objects;
+ import java.util.Set;
++import java.util.TreeMap;
++import java.util.function.Supplier;
+ 
+ /**
+  * The result of hashing the contents of a number of module artifacts.
+@@ -60,8 +64,8 @@
+      * @param algorithm   the algorithm used to create the hashes
+      * @param nameToHash  the map of module name to hash value
+      */
+-    public ModuleHashes(String algorithm, Map<String, byte[]> nameToHash) {
+-        this.algorithm = algorithm;
++    ModuleHashes(String algorithm, Map<String, byte[]> nameToHash) {
++        this.algorithm = Objects.requireNonNull(algorithm);
+         this.nameToHash = Collections.unmodifiableMap(nameToHash);
+     }
+ 
+@@ -95,54 +99,125 @@
+     }
+ 
+     /**
+-     * Computes the hash for the given file with the given message digest
+-     * algorithm.
++     * Computes a hash from the names and content of a module.
+      *
++     * @param reader the module reader to access the module content
++     * @param algorithm the name of the message digest algorithm to use
++     * @return the hash
++     * @throws IllegalArgumentException if digest algorithm is not supported
+      * @throws UncheckedIOException if an I/O error occurs
+      * @throws RuntimeException if the algorithm is not available
+      */
+-    public static byte[] computeHash(Path file, String algorithm) {
++    private static byte[] computeHash(ModuleReader reader, String algorithm) {
++        MessageDigest md;
+         try {
+-            MessageDigest md = MessageDigest.getInstance(algorithm);
+-
+-            // Ideally we would just mmap the file but this consumes too much
+-            // memory when jlink is running concurrently on very large jmods
+-            try (FileChannel fc = FileChannel.open(file)) {
+-                ByteBuffer bb = ByteBuffer.allocate(32*1024);
+-                while (fc.read(bb) > 0) {
+-                    bb.flip();
+-                    md.update(bb);
+-                    assert bb.remaining() == 0;
+-                    bb.clear();
+-                }
+-            }
+-
+-            return md.digest();
++            md = MessageDigest.getInstance(algorithm);
+         } catch (NoSuchAlgorithmException e) {
+-            throw new RuntimeException(e);
++            throw new IllegalArgumentException(e);
++        }
++        try {
++            byte[] buf = new byte[32*1024];
++            reader.list().sorted().forEach(rn -> {
++                md.update(rn.getBytes(StandardCharsets.UTF_8));
++                try (InputStream in = reader.open(rn).orElseThrow(java.util.NoSuchElementException::new)) {
++                    int n;
++                    while ((n = in.read(buf)) > 0) {
++                        md.update(buf, 0, n);
++                    }
++                } catch (IOException ioe) {
++                    throw new UncheckedIOException(ioe);
++                }
++            });
+         } catch (IOException ioe) {
+             throw new UncheckedIOException(ioe);
+         }
++        return md.digest();
+     }
+ 
+     /**
+-     * Computes the hash for every entry in the given map, returning a
+-     * {@code ModuleHashes} to encapsulate the result. The map key is
+-     * the entry name, typically the module name. The map value is the file
+-     * path to the entry (module artifact).
++     * Computes a hash from the names and content of a module.
+      *
++     * @param supplier supplies the module reader to access the module content
++     * @param algorithm the name of the message digest algorithm to use
++     * @return the hash
++     * @throws IllegalArgumentException if digest algorithm is not supported
++     * @throws UncheckedIOException if an I/O error occurs
++     */
++    static byte[] computeHash(Supplier<ModuleReader> supplier, String algorithm) {
++        try (ModuleReader reader = supplier.get()) {
++            return computeHash(reader, algorithm);
++        } catch (IOException ioe) {
++            throw new UncheckedIOException(ioe);
++        }
++    }
++
++    /**
++     * Computes the hash from the names and content of a set of modules. Returns
++     * a {@code ModuleHashes} to encapsulate the result.
++     * @param mrefs the set of modules
++     * @param algorithm the name of the message digest algorithm to use
+      * @return ModuleHashes that encapsulates the hashes
++     * @throws IllegalArgumentException if digest algorithm is not supported
++     * @throws UncheckedIOException if an I/O error occurs
+      */
+-    public static ModuleHashes generate(Map<String, Path> map, String algorithm) {
++    static ModuleHashes generate(Set<ModuleReference> mrefs, String algorithm) {
+         Map<String, byte[]> nameToHash = new HashMap<>();
+-        for (Map.Entry<String, Path> entry: map.entrySet()) {
+-            String name = entry.getKey();
+-            Path path = entry.getValue();
+-            nameToHash.put(name, computeHash(path, algorithm));
++        for (ModuleReference mref : mrefs) {
++            try (ModuleReader reader = mref.open()) {
++                byte[] hash = computeHash(reader, algorithm);
++                nameToHash.put(mref.descriptor().name(), hash);
++            } catch (IOException ioe) {
++                throw new UncheckedIOException(ioe);
++            }
+         }
+         return new ModuleHashes(algorithm, nameToHash);
+     }
+ 
++    @Override
++    public int hashCode() {
++        int h = algorithm.hashCode();
++        for (Map.Entry<String, byte[]> e : nameToHash.entrySet()) {
++            h = h * 31 + e.getKey().hashCode();
++            h = h * 31 + Arrays.hashCode(e.getValue());
++        }
++        return h;
++    }
++
++    @Override
++    public boolean equals(Object obj) {
++        if (!(obj instanceof ModuleHashes))
++            return false;
++        ModuleHashes other = (ModuleHashes) obj;
++        if (!algorithm.equals(other.algorithm)
++                || nameToHash.size() != other.nameToHash.size())
++            return false;
++        for (Map.Entry<String, byte[]> e : nameToHash.entrySet()) {
++            String name = e.getKey();
++            byte[] hash = e.getValue();
++            if (!Arrays.equals(hash, other.nameToHash.get(name)))
++                return false;
++        }
++        return true;
++    }
++
++    @Override
++    public String toString() {
++        StringBuilder sb = new StringBuilder(algorithm);
++        sb.append(" ");
++        nameToHash.entrySet()
++                .stream()
++                .sorted(Map.Entry.comparingByKey())
++                .forEach(e -> {
++                    sb.append(e.getKey());
++                    sb.append("=");
++                    byte[] ba = e.getValue();
++                    for (byte b : ba) {
++                        sb.append(String.format("%02x", b & 0xff));
++                    }
++                });
++        return sb.toString();
++    }
++
+     /**
+      * This is used by jdk.internal.module.SystemModules class
+      * generated at link time.
+diff -ru orig/jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleInfoExtender.java jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleInfoExtender.java
+--- orig/jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleInfoExtender.java	1970-01-01 01:00:01.000000000 +0100
++++ jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleInfoExtender.java	2022-04-12 16:43:12.967868689 +0200
+@@ -1,5 +1,5 @@
+ /*
+- * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
++ * Copyright (c) 2014, 2020, Oracle and/or its affiliates. All rights reserved.
+  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+  *
+  * This code is free software; you can redistribute it and/or modify it
+diff -ru orig/jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleReferences.java jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleReferences.java
+--- orig/jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleReferences.java	1970-01-01 01:00:01.000000000 +0100
++++ jdk-3cc80be736f2/src/java.base/share/classes/jdk/internal/module/ModuleReferences.java	2022-04-12 16:43:12.971868797 +0200
+@@ -1,5 +1,5 @@
+ /*
+- * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
++ * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
+  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+  *
+  * This code is free software; you can redistribute it and/or modify it
+@@ -95,7 +95,7 @@
+                                         Path file) {
+         URI uri = file.toUri();
+         Supplier<ModuleReader> supplier = () -> new JarModuleReader(file, uri);
+-        HashSupplier hasher = (a) -> ModuleHashes.computeHash(file, a);
++        HashSupplier hasher = (a) -> ModuleHashes.computeHash(supplier, a);
+         return newModule(attrs, uri, supplier, patcher, hasher);
+     }
+ 
+@@ -105,7 +105,7 @@
+     static ModuleReference newJModModule(ModuleInfo.Attributes attrs, Path file) {
+         URI uri = file.toUri();
+         Supplier<ModuleReader> supplier = () -> new JModModuleReader(file, uri);
+-        HashSupplier hasher = (a) -> ModuleHashes.computeHash(file, a);
++        HashSupplier hasher = (a) -> ModuleHashes.computeHash(supplier, a);
+         return newModule(attrs, uri, supplier, null, hasher);
+     }
+ 
diff --git a/gnu/packages/patches/openjdk-10-module3-reproducibility.patch b/gnu/packages/patches/openjdk-10-module3-reproducibility.patch
new file mode 100644
index 0000000000..bc54803bea
--- /dev/null
+++ b/gnu/packages/patches/openjdk-10-module3-reproducibility.patch
@@ -0,0 +1,34 @@
+Danny wrote.
+
+--- orig/jdk-3cc80be736f2/src/java.base/share/classes/java/lang/module/ModuleDescriptor.java	1970-01-01 01:00:01.000000000 +0100
++++ jdk-3cc80be736f2/src/java.base/share/classes/java/lang/module/ModuleDescriptor.java	2022-04-13 17:30:37.242775977 +0200
+@@ -43,6 +43,7 @@
+ import java.util.Objects;
+ import java.util.Optional;
+ import java.util.Set;
++import java.util.TreeSet;
+ import java.util.function.Supplier;
+ import java.util.stream.Collectors;
+ import java.util.stream.Stream;
+@@ -2155,9 +2156,9 @@
+          * @return The module descriptor
+          */
+         public ModuleDescriptor build() {
+-            Set<Requires> requires = new HashSet<>(this.requires.values());
+-            Set<Exports> exports = new HashSet<>(this.exports.values());
+-            Set<Opens> opens = new HashSet<>(this.opens.values());
++            Set<Requires> requires = new TreeSet<>(this.requires.values());
++            Set<Exports> exports = new TreeSet<>(this.exports.values());
++            Set<Opens> opens = new TreeSet<>(this.opens.values());
+ 
+             // add dependency on java.base
+             if (strict
+@@ -2169,7 +2170,7 @@
+                                           null));
+             }
+ 
+-            Set<Provides> provides = new HashSet<>(this.provides.values());
++            Set<Provides> provides = new TreeSet<>(this.provides.values());
+ 
+             return new ModuleDescriptor(name,
+                                         version,
diff --git a/gnu/packages/patches/openjdk-10-module4-reproducibility.patch b/gnu/packages/patches/openjdk-10-module4-reproducibility.patch
new file mode 100644
index 0000000000..051c9344eb
--- /dev/null
+++ b/gnu/packages/patches/openjdk-10-module4-reproducibility.patch
@@ -0,0 +1,14 @@
+Danny wrote it
+
+--- orig/jdk-6fa770f9f8ab/src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/SystemModulesPlugin.java	2022-04-13 19:24:12.655749459 +0200
++++ jdk-6fa770f9f8ab/src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/SystemModulesPlugin.java	2022-04-14 01:53:23.555465018 +0200
+@@ -861,7 +861,8 @@
+          */
+         private void genModuleReads(ClassWriter cw, Configuration cf) {
+             // module name -> names of modules that it reads
+-            Map<String, Set<String>> map = cf.modules().stream()
++            Map<String, Set<String>> map = cf.modules().stream()
++                    .sorted(java.util.Comparator.comparing(ResolvedModule::name))
+                     .collect(Collectors.toMap(
+                             ResolvedModule::name,
+                             m -> m.reads().stream()
