diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7d85b74b..a8156b91 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -40,7 +40,7 @@ jobs:
       - name: Check that every machine definition can be compiled
         run: cd branch && make machine_check
       - name: Make project (4x2/RTL8372)
-        run: cd branch && make CI=1 MACHINE="KP_9000_6XHML_X2" && cp output/KP_9000_6XHML_X2/rtlplayground.map /tmp/branch.map
+        run: mkdir -p /tmp/branch /tmp/main && cd branch && make CI=1 MACHINE="KP_9000_6XHML_X2" && cp output/KP_9000_6XHML_X2/rtlplayground.map output/KP_9000_6XHML_X2/rtlplayground.mem /tmp/branch/
       - name: Make project (8x1/RTL8373)
         run: cd branch && make CI=1 MACHINE="KP_9000_9XHML_X_V3_1"
       - name: Make project with the health instrumentation
@@ -49,10 +49,7 @@ jobs:
         run: |
           ln -s ../branch/toolchain main/toolchain
           PATH="$(echo "$PWD"/branch/toolchain/sdcc-*/bin):$PATH"
-          cd main && make CI=1 MACHINE="KP_9000_6XHML_X2" && cp output/KP_9000_6XHML_X2/rtlplayground.map /tmp/main.map
+          cd main && make CI=1 MACHINE="KP_9000_6XHML_X2" && cp output/KP_9000_6XHML_X2/rtlplayground.map output/KP_9000_6XHML_X2/rtlplayground.mem /tmp/main/
       - name: Calculate bank growth
         run: |
-          sed -rn 's/^([XCD]SEG|(BANK[0-9])).*=\s+([0-9]+)\. bytes.*$/MAIN_\1=\3/p' /tmp/main.map | sort -u >> "$GITHUB_ENV"
-          sed -rn 's/^([XCD]SEG|(BANK[0-9])).*=\s+([0-9]+)\. bytes.*$/BRANCH_\1=\3/p' /tmp/branch.map | sort -u >> "$GITHUB_ENV"
-          du -sb main/output/KP_9000_6XHML_X2/html_min | awk '{print "MAIN_WEB="$1}' >> "$GITHUB_ENV"
-          du -sb branch/output/KP_9000_6XHML_X2/html_min | awk '{print "BRANCH_WEB="$1}' >>"$GITHUB_ENV"
+          sh branch/tools/size_summary.sh /tmp/main /tmp/branch main/output/KP_9000_6XHML_X2/html_min branch/output/KP_9000_6XHML_X2/html_min >> "$GITHUB_STEP_SUMMARY"
diff --git a/tools/size_summary.sh b/tools/size_summary.sh
new file mode 100644
index 00000000..289a8606
--- /dev/null
+++ b/tools/size_summary.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+seg() {
+	sed -rn "s/^$1[^=]*=\\s+([0-9]+)\\. bytes.*$/\\1/p" "$2/rtlplayground.map" | head -n 1
+}
+stack() {
+	sed -rn 's/.* with ([0-9]+) bytes available.*/\1/p' "$1/rtlplayground.mem"
+}
+row() {
+	echo "| $1 | $2 | $3 | $((${3:-0} - ${2:-0})) |"
+}
+echo "### KP_9000_6XHML_X2"
+echo
+echo "| | main | branch | change |"
+echo "| --- | ---: | ---: | ---: |"
+for s in HOME CSEG BANK1 BANK2 BANK3 BANK4 XSEG; do
+	row "$s" "$(seg $s "$1")" "$(seg $s "$2")"
+done
+row "stack available" "$(stack "$1")" "$(stack "$2")"
+row "web" "$(du -sb "$3" | cut -f1)" "$(du -sb "$4" | cut -f1)"