DragonFlyBSD Works On EFI Runtime ABI Support, But Still Experimental

[phoronix]

Phoronix: DragonFlyBSD Works On EFI Runtime ABI Support, But Still Experimental

The next release of DragonFlyBSD will feature better EFI support...

http://www.phoronix.com/scan.php?page=news_item&px=DragonFly-EFI-Runtime-Support

[wikinevick]

Given the code was taken from FreeBSD, and it already works there, I wonder how this is considered news.

[starshipeleven]

Given the code was taken from FreeBSD, and it already works there, I wonder how this is considered news.

BSDs have more differences between each other than the average linux distro vs another linux distro, so this isn't the same as saying "Ubuntu is now using a Fedora feature".

Which is why someone managed to brick his PC with it (probably deleted EFI vars and that board firmware, being a piece of shit, couldn't recover from that).

[aht0]

BSDs have more differences between each other than the average linux distro vs another linux distro, so this isn't the same as saying "Ubuntu is now using a Fedora feature".

Given the code was taken from FreeBSD, and it already works there, I wonder how this is considered news.

Dragonfly has hybrid kernel while FreeBSD kernel is monolithic. Should say something about their differences on grass level..

[c117152]

Which is why someone managed to brick his PC with it (probably deleted EFI vars and that board firmware, being a piece of shit, couldn't recover from that).

Even Intel's UEFI reference firmwares are very fragile there. It's easy to corrupt the var store with multiple identical entries resulting in undefined behavior and the length values for bound checking are stored right next to the actual values so they're trivial to overflow.

Overall, it's a REALLY shitty database both on the binary level and on the APIs level with regards to the kernel returning pointers and allowing overflowing despite the existing entries bounds.

Regardless, messing the UEFI isn't fatal. 99% of the time you simply pick up an EEPROM writer and flash a clean firmware off the manufacturer's site. If you're lucky, you can even make due with something like a Raspberry Pi and a clamp. Regardless, if you're working on the SPI level you should have those ready.

[starshipeleven]

Regardless, messing the UEFI isn't fatal. 99% of the time you simply pick up an EEPROM writer and flash a clean firmware off the manufacturer's site. If you're lucky, you can even make due with something like a Raspberry Pi and a clamp. Regardless, if you're working on the SPI level you should have those ready.

Well, ok, for a dev it is very annoying but doable, but it's not something you want your users to do on their own.
Flashing SPI chips on average requires you to desolder the chip as other stuff on the board interferes with operations, and for laptops it's also common to have the chip in inaccessible places so you need to tear down the whole damn thing iFixit-style.

Obligatory mention of the fact that recent versions of Flashrom have added support for one of the cheapest chinese SPI flasher controllers.

https://www.flashrom.org/Flashrom/0.9.9

Just search for "CH341A" and you'll find swarms on ebay or aliexpress that can be bought for peanuts.

You have no more reasons to not have your very own Flashrom-supported SPI flasher, today!

[wikinevick]

Dragonfly has hybrid kernel while FreeBSD kernel is monolithic. Should say something about their differences on grass level..

Why do people like to make up BS?
Dragonfly is not "hybrid" and even if it were, that has not effect on the bootloader.

[starshipeleven]

Why do people like to make up BS?

He might have read wikipedia or the other sources stating such. https://en.wikipedia.org/wiki/DragonFly_BSD
DragonFly's kernel is a hybrid, containing features of both monolithic and microkernels, such as the message passing capability of microkernels enabling larger portions of the OS to benefit from protected memory, as well as retaining the speed of monolithic kernels for certain critical tasks.

Dragonfly is not "hybrid" and even if it were, that has not effect on the bootloader.

UEFI is a board firmware with integrated boot manager (but no bootloader, because LOL WTF), and the APIs to talk with it are in the kernel.

Differences in kernels mean that you cannot just copy-paste hardware-operating code from another BSD that has a kernel with a different design like FreeBSD.

Quoting verbatim a relevant part of the commit:

* Port from FreeBSD. Use our vmspace management functions to handle
the specialized pmap requirements instead of rerolling the page
table. Make adjustments for differences in the device API. etc.

[aht0]

Why do people like to make up BS?
Dragonfly is not "hybrid" and even if it were, that has not effect on the bootloader.

It has hybrid kernel all right. Lone BSD with that type of kernel. Probably achieved by having huge chunks of former FreeBSD kernel re-written after forking.

[c117152]

Flashing SPI chips on average requires you to desolder the chip as other stuff on the board interferes with operations, and for laptops it's also common to have the chip in inaccessible places so you need to tear down the whole damn thing iFixit-style.

0_o ... There's clips for that... http://www.ebay.com/bhp/soic-test-clip

Just search for "CH341A" and you'll find swarms on ebay or aliexpress that can be bought for peanuts.

Already have a few soldered with different voltage regulators since I need 1.8v Vcc on some Winbond chips and 3.3v \ 5v on others... I get ChipHead silicon priced on the bulk through a friend's workplace so I end up buying a bit more then I should and just solder everything instead of breadboard them... Regardless, the clips are designed for those as well. The actual socket is some kind of standard from 3M so you usually don't need to pull alligators and pins.