diff --git a/build/org.eclipse.cdt.managedbuilder.gnu.ui/META-INF/MANIFEST.MF b/build/org.eclipse.cdt.managedbuilder.gnu.ui/META-INF/MANIFEST.MF
index 58aee845d73..20b5c7faba7 100644
--- a/build/org.eclipse.cdt.managedbuilder.gnu.ui/META-INF/MANIFEST.MF
+++ b/build/org.eclipse.cdt.managedbuilder.gnu.ui/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.cdt.managedbuilder.gnu.ui; singleton:=true
-Bundle-Version: 8.6.100.qualifier
+Bundle-Version: 8.7.0.qualifier
 Bundle-Activator: org.eclipse.cdt.managedbuilder.gnu.ui.GnuUIPlugin
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
diff --git a/build/org.eclipse.cdt.managedbuilder.gnu.ui/plugin.xml b/build/org.eclipse.cdt.managedbuilder.gnu.ui/plugin.xml
index 29596312772..635dfd36d69 100644
--- a/build/org.eclipse.cdt.managedbuilder.gnu.ui/plugin.xml
+++ b/build/org.eclipse.cdt.managedbuilder.gnu.ui/plugin.xml
@@ -565,7 +565,7 @@
                id="gnu.windres.option.preprocessor.undefined.symbols"/>
       </tool-->
       <tool
-            command="as"
+            command="gcc"
             name="%ToolName.assembler.gnu"
             outputFlag="-o"
             id="cdt.managedbuild.tool.gnu.assembler"
@@ -579,8 +579,27 @@
          <option
                name="%Option.Gnu.Assembler.Flags"
                category="gnu.asm.category.general"
+               commandGenerator="org.eclipse.cdt.managedbuilder.gnu.ui.GnuAsmFlagsCommandGenerator"
                valueType="string"
                id="gnu.both.asm.option.flags">
+            <enablement
+                  type="CONTAINER_ATTRIBUTE"
+                  attribute="defaultValue"
+                  value="-c"
+                  extensionAdjustment="false">
+                <checkBuildProperty
+                     property="org.eclipse.cdt.build.core.buildType"
+                     value="org.eclipse.cdt.build.core.buildType.release"/>
+            </enablement>
+            <enablement
+                  type="CONTAINER_ATTRIBUTE"
+                  attribute="defaultValue"
+                  value="-c -g"
+                  extensionAdjustment="false">
+               <checkBuildProperty
+                     property="org.eclipse.cdt.build.core.buildType"
+                     value="org.eclipse.cdt.build.core.buildType.debug"/>
+            </enablement>
          </option>
          <option
                command="-I"
@@ -607,7 +626,7 @@
                id="cdt.managedbuild.tool.gnu.assembler.input"
                languageId="org.eclipse.cdt.core.assembly"
                sourceContentType="org.eclipse.cdt.core.asmSource"
-               sources="s,S">
+               sources="s,sx,S">
          </inputType>
          <outputType
 			outputs="o"
diff --git a/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/ui/GnuAsmFlagsCommandGenerator.java b/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/ui/GnuAsmFlagsCommandGenerator.java
new file mode 100644
index 00000000000..ee57cca7929
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.gnu.ui/src/org/eclipse/cdt/managedbuilder/gnu/ui/GnuAsmFlagsCommandGenerator.java
@@ -0,0 +1,65 @@
+/*******************************************************************************
+ * Copyright (c) 2024 John Dallaway and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *    John Dallaway - initial implementation (#666)
+ *******************************************************************************/
+package org.eclipse.cdt.managedbuilder.gnu.ui;
+
+import java.util.regex.Pattern;
+
+import org.eclipse.cdt.core.cdtvariables.CdtVariableException;
+import org.eclipse.cdt.managedbuilder.core.BuildException;
+import org.eclipse.cdt.managedbuilder.core.IHoldsOptions;
+import org.eclipse.cdt.managedbuilder.core.IOption;
+import org.eclipse.cdt.managedbuilder.core.IOptionCommandGenerator;
+import org.eclipse.cdt.managedbuilder.core.ITool;
+import org.eclipse.cdt.utils.cdtvariables.CdtVariableResolver;
+import org.eclipse.cdt.utils.cdtvariables.IVariableSubstitutor;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.Status;
+
+/**
+ * Assembler flags command generator.
+ * @noextend This class is not intended to be subclassed by clients.
+ * @noinstantiate This class is not intended to be instantiated by clients.
+ * @since 8.7
+ */
+public class GnuAsmFlagsCommandGenerator implements IOptionCommandGenerator {
+
+	private static final Pattern DO_NOT_LINK_FLAG = Pattern.compile("(^|\\s)-c($|\\s)"); //$NON-NLS-1$
+	private static final Pattern ASM_FLAG = Pattern.compile("-[aDKLR]\\S*"); //$NON-NLS-1$
+
+	@Override
+	public String generateCommand(IOption option, IVariableSubstitutor macroSubstitutor) {
+		IHoldsOptions optionHolder = option.getOptionHolder();
+		if (optionHolder instanceof ITool tool) {
+			try {
+				// if the default assembler tool command has not been overridden
+				if (tool.getToolCommand().equals("gcc") && option.getCommand().isEmpty() //$NON-NLS-1$
+						&& IOption.STRING == option.getValueType()) {
+					String optionValue = option.getStringValue();
+					String command = CdtVariableResolver.resolveToString(optionValue, macroSubstitutor);
+					if (!DO_NOT_LINK_FLAG.matcher(command).find()) {
+						// if the "-c" flag is not already present on the command line we
+						// assume the flags target the GNU "as" command line rather than the
+						// "gcc" command line so we add the "-c" flag and apply the "-Wa,"
+						// prefix to those flags that are intended only for the assembler
+						return "-c " + ASM_FLAG.matcher(command).replaceAll("-Wa,$0"); //$NON-NLS-1$ //$NON-NLS-2$
+					}
+				}
+			} catch (BuildException | CdtVariableException e) {
+				Platform.getLog(getClass()).log(Status.error("Error generating GNU assembler command", e)); //$NON-NLS-1$
+			}
+		}
+		return null; // fallback to default command generator
+	}
+
+}
diff --git a/core/org.eclipse.cdt.core/plugin.xml b/core/org.eclipse.cdt.core/plugin.xml
index 1f85cd2d0e4..ee3cbd91b5d 100644
--- a/core/org.eclipse.cdt.core/plugin.xml
+++ b/core/org.eclipse.cdt.core/plugin.xml
@@ -625,7 +625,7 @@
 	  <!-- declares a content type for ASM Source files -->
       <content-type id="asmSource" name="%asmSourceName" 
           base-type="org.eclipse.core.runtime.text"
-          file-extensions="S,s,asm,ASM"
+          file-extensions="S,s,sx,asm,ASM"
           priority="high"/>
    </extension>