Boot-Repair vs Petitboot

Boot-Repair is free Linux software for restoring access to operating systems after boot failures. It addresses common GRUB problems and situations where Ubuntu or Windows no longer starts after another operating system is installed. Its Recommended Repair can reinstall GRUB and recover access to previously installed systems. Advanced options provide partition-table and boot-sector backups, GRUB setting changes, restoration of a Windows-compatible MBR, and filesystem repair. Boot-Repair can produce a Boot-Info diagnosis for sharing with helpers by email or on a forum. You choose whether to upload that report to Pastebin or keep it local; uploaded reports are described as expiring after some days. Boot-Repair-Disk starts the tool automatically and also includes OS-Uninstaller and Boot-Info. It can also run from Ubuntu, Debian, and derivative live environments. The project describes automatic backups and says the software is distributed without warranty.

Petitboot is a free, GPL-2.0-licensed bootloader implemented by userspace programs in a small Linux image. It discovers devices and bootable images, reads configurations such as GRUB, SYSLINUX, and Yaboot, then starts systems through Linux kexec. Its primary interface is an ncurses menu for viewing boot choices and system information, changing settings, running plugins, and opening a shell. Operating-system images can be loaded over HTTP, HTTPS, NFS, SFTP, or TFTP. Basic functionality is available on platforms that support kexec, while documented platform implementations include POWER systems using OPAL firmware and ARM64 systems with efivarfs support. On supported systems, inband IPMI can report BMC information and alter boot behavior through boot-device overrides. Plugins package and run binaries and may be discovered locally or in PXE network files. The pb-discover server finds and configures devices, while user interfaces communicate through pb-protocol. The included pb-sos utility gathers diagnostic and crash information.