Furthermore, Microsoft has experimented with "Hotpatching" (AB for the Windows kernel) and Linux’s kexec system calls are evolving to mimic slot-based switching without hardware reboots. If you are a desktop user running Windows and Ubuntu, stick with GRUB. Traditional dual-boot is simpler for distinct OSes.
[slot.rootfs.1] device=/dev/mmcblk0p4 type=ext4 bootname=B To switch from Slot A to Slot B at runtime: ab multiboot
This article dives deep into what AB Multiboot is, how it works, why it outperforms legacy setups, and how you can implement it on your own hardware. At its core, AB Multiboot is a partitioning and boot strategy that maintains two complete copies of a system’s firmware, kernel, and data partitions—labeled "Slot A" and "Slot B." how it works
[system] compatible=my-device [slot.rootfs.0] device=/dev/mmcblk0p2 type=ext4 bootname=A why it outperforms legacy setups
menuentry "Boot Slot A" set root=(hd0,1) linux /vmlinuz root=/dev/mmcblk0p2 slot=A
| Feature | Traditional Dual-Boot (GRUB/Windows) | AB Multiboot | | :--- | :--- | :--- | | | 30-60 seconds (full kernel reload) | 5-10 seconds (direct slot flip) | | Safety | High risk of bricking on update failure | Zero risk (automatic rollback) | | Storage Overhead | Low (shares user data) | High (full duplicate system partitions) | | Boot Menu | Manual selection required | Silent; uses metadata flags | | Use Case | Permanent different OSes (Windows + Linux) | Rapid testing, dev builds, embedded systems |