The rEFInd Boot Manager:
The Future of rEFInd
by Roderick W. Smith, rodsmith@rodsbooks.com
Originally written: 3/14/2012; last Web page update:
3/4/2023, referencing rEFInd 0.14.0
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This page is part of the documentation for the rEFInd boot manager. If a Web search has brought you here, you may want to start at the main page.
This page exists to document some of rEFInd's known bugs and limitations, as well as features I hope to add in the future. Some of the items on this list are things that you may be able to help with, so if you'd like to contribute, feel free to drop me a line!
The following list groups things that need to be done into broad categories. In some cases, there's some ambiguity about how an item might best be classified. Without further ado, then:
- Tasks with which non-programmers can help:
- Testing! rEFIt was complex enough that changes such as the ones
I've made have the potential to disrupt the program's operation in
unexpected ways. Since the initial 0.2.0 release, I've continued to
add features to rEFInd, and every new feature is another way for
bugs to get into the program. I can only test on a handful of
systems with a limited number of configurations. Therefore, if you
try rEFInd and run into bugs, please report them to me!
- rEFIt's original design, and hence rEFInd's design, enables easy
theming by replacing icon files. If you'd like to design a new theme
for rEFInd, feel free to submit it. I might or might not replace the
icons it uses now (most of which come from the Aw0ken
icons package), but I may provide links to themes on this Web site
(or even host them on the project's Sourceforge page). For more
information on designing themes for rEFInd, see the Theming rEFInd page.
- Improvements to existing features:
- As described in reference to version 0.9.2 on the Revisions page, rEFInd includes a
delicate and hackish workaround to a problem introduced by Shim
0.8. Developing a better solution to that problem is a high
priority.
- rEFInd's Makefiles and, to a lesser extent, C code,
support x86, x86-64, and ARM64 CPUs. EFI is also
available for Itanium (IA-64) and ARM32 CPUs, so I'd like to add
this support.
- Currently, rEFInd can detect whether it's compiled for x86,
x86-64, or ARM64 systems and displays this information in
its "About" screen (AboutrEFInd() in main.c). I'd
like to add detection for Itanium and 32-bit ARM systems, but I
have no way to test such changes.
- Further to the preceding, rEFInd's GPT-scanning code (used to
extract partition names) includes assumptions about byte order, and
so will work only on little-endian CPUs such as the x86 and
x86-64.
- A way to set the color of the font would be useful for theming
purposes.
- The program's font features could be greatly improved by enabling
use of a standard font format, by enabling use of non-ASCII
characters, and by enabling use of variable-width as well as
monospace fonts.
- The default_selection might be expanded to support some
form of specification of disk types, as in a special entry for any
optical disk or any external disk, no matter what its name is.
- It would be useful to be able to specify paths to boot loaders
and/or initial RAM disks relative to the rEFInd directory (or the
boot loader's directory, in the case of initrds).
- Currently the background for certain subscreens (such as the
information page or submenu listings) is a solid color based on the
upper-left corner of the screen. Having an option to support a
transparent background is desirable to some users.
- When delivering rEFInd as a boot loader from a network server,
rEFInd is limited to its default options and can boot only local
OSes, not network OSes. The cause is that the server delivers a
single file, so rEFInd is divorced from its configuration and
support files.
- A way to identify specific Windows versions and present unique
icons or change the text is desirable. Currently, a crude
distinction of XP and earlier vs. Vista and later is possible for
BIOS-booting on Macs, but no such distinction is made for EFI-mode
booting, and nothing finer-grained is attempted. Improvements will
probably require identifying unique features of each version's boot
loader files or boot sector code.
- The support for booting legacy (BIOS) OSes on UEFI-based PCs
currently has a number of limitations. Most importantly, it works
off of the list of boot devices stored in the computer's NVRAM. I'd
prefer to have it scan disks and partitions, as the Mac's legacy
boot support does. Also, the UEFI legacy boot code presents empty
optical drives and uses generic icons rather than OS-specific icons.
This said, BIOS support is becoming increasingly unimportant as the
transition from BIOS to EFI continues, so I'm unlikely to put effort
into this issue myself.
- Known bugs that need squashing:
- I've been receiving reports of blank screens when using rEFInd on
some recent Mac models. I've investigated this with the help of one
user, and I suspect that Apple has made changes to its firmware that
are likely to affect just about any EFI program. I don't have a
definitive solution, but at least one user has reported that
removing rEFInd's drivers has caused the problem to go into
remission. Changes made in version 0.11.0 improve error reporting on
Macs, which may help with this issue.
- On Macs with HiDPI (aka "Retina") displays, booting macOS via rEFInd
results in a lower resolution than booting macOS normally.
Similarly, booting any other OS results in sub-optimal resolution.
This problem is mitigated by the new (as of rEFInd 0.13.0) ability
to boot to a firmware-defined boot option; booting in this way
eliminates the problem for macOS, but not for Linux and probably not
for Windows. A better solution is desirable. See this YouTube video
and This
AskUbuntu question and answers.
- Some EFIs have bugs that cause the allegedly case-insensitive
StriCmp() function to perform a case-sensitive comparison.
This causes any number of bugs in file matching. For instance:
Changing the case of icon filename extensions (or various other
parts of icon filenames) causes icons to be replaced by ugly
"generic" ones; and rEFInd sometimes appears in its own menu (the
firmware sometimes returns an all-caps version of the filename, but
other times returns the filename with the correct case, causing a
mismatch if the path includes lowercase elements). This problem is
worse when compiling rEFInd with GNU-EFI than with Tianocore.
Version 0.9.1 has made improvements on this score, but some issues
may continue to lurk.
- The Shutdown option works correctly on Macs, but not on many UEFI-based
PCs. On such systems, Shutdown reboots the computer. This should be
fixed.
- The media-ejection feature (F12) should be extended to work on
UEFI-based PCs and early Macs. At the moment, it relies on an
Apple-specific EFI extension, and I know of no standard EFI way to
do it.
- A couple of Mac users have reported that the brightness-adjustment
features in Windows don't work when Windows is booted via rEFInd,
but that these features do work when Windows is booted via the Mac's
built-in boot manager. Unfortunately, I have no idea what causes
this problem, I have no Windows installation on my Macs, and I have
no way to debug it. Therefore, it's unlikely that I'll be able to
fix this problem myself; but if you have the equipment and skill to
do so, I'd be interested in receiving a patch.
- If you use a true MBR disk on a Mac to boot Windows or some other
BIOS-only OS, and if that disk has an extended partition, bogus
additional BIOS/legacy-bootable options may appear in the rEFInd
menu. The reason appears to be a bug in the handling of
extended/logical partitions in the refind/lib.c file, but
I haven't fully tracked it down.
- The re-scan feature occasionally produces odd results, such as
ignoring new media or keeping old media that have been ejected.
This should be investigated and fixed.
- The "scanning for boot loaders" message that appears at startup and
during the re-scan feature is primitive. Some sort of dynamic icon
would be nice, but perhaps impractical, given the single-tasking
nature of EFI.
- On my Mac Mini, launching a shell, returning, and performing a
re-scan causes the system to be unable to launch the shell again. I
have not observed this behavior on UEFI-based PCs. It seems to be
caused by a truncated DevicePath to the shell, which includes the
shell's pathname but not the device identifier.
- When specifying a volume by name in dont_scan_dirs,
slashes are converted to backslashes in the specification but not
in the actual volume name read from disk. Thus, you can't specify a
volume by name if it includes a slash (as in Fedora
/boot). Workarounds are to rename the volume to omit the slash
and to use a partition GUID rather than a volume label.
- The code is in need of review to search for memory leaks and
similar problems.
- If the user has a Linux software RAID 1 array with Btrfs, HFS+, or
FAT filesystem, rEFInd will detect kernels or boot loaders in RAID 1
twice. Checks to prevent this with ext2/3/4fs and ReiserFS already
exist; these checks could be expanded to block such duplication with
more filesystems. Using the in-rEFInd hiding feature (activated by
the Delete or minus [-] key) can remove a redundant
entry.
- Some Macs experience problems with waking up from suspend states
when rEFInd is installed. Using
pmset to disable the autopoweroff option is claimed
by some to at least partially fix the problem, though. Using the
--ownhfs installation option may also help in some
cases.
- If you activate BIOS-mode support on UEFI-based PCs, you may find
multiple copies of the BIOS-mode loaders added to your firmware's
boot manager. Only one copy shows up in rEFInd, though.
- If you have a manual boot stanza for a Linux kernel with both an
initrd line and a second initrd file specified on the
options line, both initrd files will be passed to the
kernel in most situations; however, one will be omitted if
you enter the submenu (via F2, Insert, or Tab) and select the
default entry there. This bug is caused by the convoluted way rEFInd
generates its submenus, and I'm putting off fixing it until I can
give that code the overhaul it desperately needs.
- New features I'd like to add:
- I'd like to find a way to enable users to enter customizations for
boot options and then save them to the refind.conf file.
One possible way to implement this would be to have manual boot
stanzas override auto-detected boot loader definitions for the same
boot loader file.
- Along similar lines, some users have asked for a way to take
detected boot programs and create a set of manual boot stanzas for
them, so that they can be modified manually.
- Better support for touchscreens and/or configurable buttons for
rEFInd's actions would enable use of rEFInd on tablet computers that
lack complete keyboards. (Version 0.10.4 supports some
touchscreens, but this feature relies on support in the firmware,
which is not universally present.)
- The ability to rotate the display for users who rotate their
monitors or who use tablets would be helpful.
- GRUB provides a configuration-file command called outb
that enables manipulating hardware registers. Something similar,
via the mm command, can be done in the EFI shell. I'd like
to add such a feature to rEFInd, since it enables doing things like
disabling one or another video output on Macs with two video
cards.
- I have thoughts about creating an EFI configuration tool and
information utility—something to tell you about your hard
disks, enable you to manage MOKs, adjust boot loader priority in
the NVRAM, and so on. This would be useful in system maintenance
and in recovering from boot problems.
- It should be possible to override specific auto-detected boot loader
settings—say, to change the icon for one specific boot
loader.
- A GUI configuration tool for host OSes (Linux, macOS, Windows, etc.)
would be nice, but it's low on my personal priority list. If you'd
like to contribute, I prefer something written in a cross-platform
GUI toolkit, so that a single code base can be used on any of the
major OSes.
- The ability to produce audio output (at least a simple "beep") to signal
to visually impaired users when rEFInd is ready to accept input would be
helpful.
- Improvements to the EFI drivers:
- Drivers for additional filesystems are desirable. Only XFS and JFS
are missing from the major Linux filesystems. UDF would also be a
welcome addition, as might drivers for other OSes (say, for the
BSDs, especially if BSD developers create a boot loader similar to
Linux's EFI stub loader). Also along these lines, adding drivers
for Linux LVM and RAID setups would be useful.
- This may not be possible, or it may require a new driver, but a way
to have the drivers access files (like a Linux loopback mount) is
desirable.
- When built with the GNU-EFI package, an attempt to load more than
one driver on my 32-bit Mac Mini causes the computer to hang. I do
not have this problem with 64-bit drivers on my UEFI-based
computers. I don't know if this is a 32-bit issue or a Mac issue.
This is not relevant if you're using my binary package,
since I build it with the TianoCore EDK2, and the drivers built in
that way don't exhibit this bug.
- Improvements to gptsync, refind-install, or other
support tools:
- The gptsync program can return misleading error codes
under some circumstances, such as when it makes no changes to the
partition table. Fix this.
- rEFInd's support for network booting is primitive and relies on the
external iPXE package. In my own testing, iPXE retrieves the
BIOS-mode boot loader from some servers that offer both, which makes
it useless on those networks. The reboot-to-firmware-boot-options
feature in rEFInd 0.13.0 at least partially addresses this
problem.
- The handling of encrypted local Secure Boot keys by
refind-install could be improved. Specifically, if you
install without encrypted keys and then run refind-install
with --encryptkeys, or vice-versa, the script is likely to
ask for keys repeatedly. Error handling (if an incorrect key is
entered, for instance) is also poor. If an encrypted key is used and
a rEFInd RPM or Debian package is installed, that installation may
fail to set things up correctly.
- A Mac-specific package is highly desirable, but seems impractical,
given SIP.
copyright © 2012–2023 by Roderick W. Smith
This document is licensed under the terms of the GNU Free Documentation License (FDL), version 1.3.
If you have problems with or comments about this Web page, please e-mail me at rodsmith@rodsbooks.com. Thanks.
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