From 34de424611ffada9a0077d0650f2320a11b1e80e Mon Sep 17 00:00:00 2001
From: Dan <dnadna59@gmail.com>
Date: Sun, 26 Apr 2026 19:54:23 +0200
Subject: [PATCH] zram for ubuntu; kexec.sh for single distro

---
 boot/kexec.sh                      | 5 +++++
 distros/ubuntu/image.yaml          | 4 ++++
 distros/ubuntu2604/image.yaml      | 4 ++++
 docker/image-builder/entrypoint.sh | 1 +
 4 files changed, 14 insertions(+)
 create mode 100644 boot/kexec.sh

diff --git a/boot/kexec.sh b/boot/kexec.sh
new file mode 100644
index 0000000..cf740f2
--- /dev/null
+++ b/boot/kexec.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+set -e
+BOOT=/boot/efi
+kexec -l "$BOOT/bzImage" --initrd="$BOOT/initrd.img" --command-line="$(cat $BOOT/cmdline.txt)"
+kexec -e
diff --git a/distros/ubuntu/image.yaml b/distros/ubuntu/image.yaml
index d084f16..e8ade7b 100644
--- a/distros/ubuntu/image.yaml
+++ b/distros/ubuntu/image.yaml
@@ -46,6 +46,7 @@ packages:
     - fonts-liberation
     - fonts-dejavu
     - fontconfig
+    - systemd-zram-generator
     action: install
 
 files:
@@ -131,6 +132,9 @@ actions:
     sed -i 's/^#*PasswordAuthentication.*/PasswordAuthentication yes/' /etc/ssh/sshd_config
     systemctl enable ssh
 
+    # zram swap: half of RAM, zstd compressed
+    printf '[zram0]\nzram-size = ram / 2\ncompression-algorithm = zstd\n' > /etc/systemd/zram-generator.conf
+
 - trigger: post-files
   action: |-
     #!/bin/bash
diff --git a/distros/ubuntu2604/image.yaml b/distros/ubuntu2604/image.yaml
index e6b106b..14cc806 100644
--- a/distros/ubuntu2604/image.yaml
+++ b/distros/ubuntu2604/image.yaml
@@ -46,6 +46,7 @@ packages:
     - fonts-liberation
     - fonts-dejavu
     - fontconfig
+    - systemd-zram-generator
     action: install
 
 files:
@@ -112,6 +113,9 @@ actions:
     sed -i 's/^#*PasswordAuthentication.*/PasswordAuthentication yes/' /etc/ssh/sshd_config
     systemctl enable ssh
 
+    # zram swap: half of RAM, zstd compressed
+    printf '[zram0]\nzram-size = ram / 2\ncompression-algorithm = zstd\n' > /etc/systemd/zram-generator.conf
+
 - trigger: post-files
   action: |-
     #!/bin/bash
diff --git a/docker/image-builder/entrypoint.sh b/docker/image-builder/entrypoint.sh
index bb896e9..3514e6c 100755
--- a/docker/image-builder/entrypoint.sh
+++ b/docker/image-builder/entrypoint.sh
@@ -158,6 +158,7 @@ echo "=== Assembling boot partition ==="
 mv /tmp/usb_root/boot/efi/* /tmp/usb_efi/ 2>/dev/null || true
 sed "s|__DISTRO__|$ROOT_LABEL|" /repo/boot/cmdline.txt > /tmp/usb_efi/cmdline.txt
 cp /repo/boot/vram.txt     /tmp/usb_efi/
+cp /repo/boot/kexec.sh     /tmp/usb_efi/
 sync
 
 umount /tmp/usb_root /tmp/usb_efi