From 58739c9f1b79bed4d250138157e77a73ded99af6 Mon Sep 17 00:00:00 2001
From: Adphi <philippe.adrien.nousse@gmail.com>
Date: Wed, 29 Apr 2026 17:06:10 +0200
Subject: [PATCH] feat: Add grub and grub-efi boot support for Rocky and
 AlmaLinux 9+

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>
---
 e2e/e2e_test.go             |  2 +-
 grub.go                     |  6 +++---
 grub_efi.go                 | 19 ++++++++++++++++---
 templates/centos.Dockerfile |  4 ++--
 4 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/e2e/e2e_test.go b/e2e/e2e_test.go
index d349158..2338c66 100644
--- a/e2e/e2e_test.go
+++ b/e2e/e2e_test.go
@@ -135,7 +135,7 @@ imgs:
 						require.NoError(os.Remove(out))
 					}
 
-					require.NoError(docker.RunD2VM(ctx, d2vm.Image, d2vm.Version, dir, dir, "convert", append([]string{"-p", "root", "-o", "/out/" + filepath.Base(out), "-v", "--keep-cache", img.name}, tt.args...)...))
+					require.NoError(docker.RunD2VM(ctx, d2vm.Image, d2vm.Version, dir, dir, "convert", append([]string{"-p", "root", "-o", "/out/" + filepath.Base(out), "-v", "--keep-cache", "--boot-size=250", img.name}, tt.args...)...))
 
 					inr, inw := io.Pipe()
 					defer inr.Close()
diff --git a/grub.go b/grub.go
index e853f4a..e54ae97 100644
--- a/grub.go
+++ b/grub.go
@@ -41,7 +41,7 @@ func (g grub) Setup(ctx context.Context, dev, root string, cmdline string) error
 		return err
 	}
 	defer clean()
-	if err := g.install(ctx, "--target=x86_64-efi", "--efi-directory=/boot", "--no-nvram", "--removable", "--no-floppy"); err != nil {
+	if err := g.install(ctx, "--target=x86_64-efi", "--efi-directory=/boot", "--no-nvram", "--removable", "--no-floppy", "--force"); err != nil {
 		return err
 	}
 	if err := g.install(ctx, "--target=i386-pc", "--boot-directory=/boot", dev); err != nil {
@@ -61,8 +61,8 @@ func (g grubProvider) New(c Config, r OSRelease, arch string) (Bootloader, error
 	if arch != "x86_64" {
 		return nil, fmt.Errorf("grub is only supported for amd64")
 	}
-	if r.ID == ReleaseCentOS || r.ID == ReleaseRocky || r.ID == ReleaseAlmaLinux {
-		return nil, fmt.Errorf("grub (efi) is not supported for CentOS / Rocky / AlmaLinux, use grub-bios instead")
+	if err := checkGrubEFISupport(r); err != nil {
+		return nil, err
 	}
 	return grub{grubCommon: newGrubCommon(c, r)}, nil
 }
diff --git a/grub_efi.go b/grub_efi.go
index 4c3a83f..c544c97 100644
--- a/grub_efi.go
+++ b/grub_efi.go
@@ -17,6 +17,8 @@ package d2vm
 import (
 	"context"
 	"fmt"
+	"strconv"
+	"strings"
 
 	"github.com/sirupsen/logrus"
 )
@@ -42,7 +44,7 @@ func (g grubEFI) Setup(ctx context.Context, dev, root string, cmdline string) er
 		return err
 	}
 	defer clean()
-	if err := g.install(ctx, "--target="+g.arch+"-efi", "--efi-directory=/boot", "--no-nvram", "--removable", "--no-floppy"); err != nil {
+	if err := g.install(ctx, "--target="+g.arch+"-efi", "--efi-directory=/boot", "--no-nvram", "--removable", "--no-floppy", "--force"); err != nil {
 		return err
 	}
 	if err := g.mkconfig(ctx); err != nil {
@@ -56,8 +58,8 @@ type grubEFIProvider struct {
 }
 
 func (g grubEFIProvider) New(c Config, r OSRelease, arch string) (Bootloader, error) {
-	if r.ID == ReleaseCentOS || r.ID == ReleaseRocky || r.ID == ReleaseAlmaLinux {
-		return nil, fmt.Errorf("grub-efi is not supported for CentOS, use grub-bios instead")
+	if err := checkGrubEFISupport(r); err != nil {
+		return nil, err
 	}
 	return grubEFI{grubCommon: newGrubCommon(c, r), arch: arch}, nil
 }
@@ -66,6 +68,17 @@ func (g grubEFIProvider) Name() string {
 	return "grub-efi"
 }
 
+func checkGrubEFISupport(r OSRelease) error {
+	if r.ID == ReleaseCentOS {
+		return fmt.Errorf("grub (efi) is not supported for CentOS, use grub-bios instead")
+	}
+	v, _ := strconv.Atoi(strings.Split(r.VersionID, ".")[0])
+	if (r.ID == ReleaseAlmaLinux || r.ID == ReleaseRocky) && v < 9 {
+		return fmt.Errorf("grub (efi) is not supported for %s (%s), use 9+ releases or grub-bios instead", r.ID, r.VersionID)
+	}
+	return nil
+}
+
 func init() {
 	RegisterBootloaderProvider(grubEFIProvider{})
 }
diff --git a/templates/centos.Dockerfile b/templates/centos.Dockerfile
index e584ef8..8a1af85 100644
--- a/templates/centos.Dockerfile
+++ b/templates/centos.Dockerfile
@@ -50,8 +50,8 @@ RUN set -e; \
       kver="$(basename "$dir")"; \
       initrd="${dir}/initrd"; \
       [ -e "$initrd" ] || continue; \
-      ln -sf "${linux#/boot/}" "/boot/vmlinuz-${kver}"; \
-      ln -sf "${initrd#/boot/}" "/boot/initramfs-${kver}.img"; \
+      mv "${linux}" "/boot/vmlinuz-${kver}"; \
+      mv "${initrd}" "/boot/initramfs-${kver}.img"; \
     done
 {{- else }}
 RUN cd /boot && \