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by Electron752
Sat Apr 09, 2016 2:08 pm
Forum: Bare metal, Assembly language
Topic: Boot 64bit linux without u-boot?
Replies: 5
Views: 2339

Re: Boot 64bit linux without u-boot?

It seems like all I really need to do then to remove u-boot is run a command line like this: objcopy --gap-fill=0xff -j .text -j .rodata -j .data -O binary vmlinux vmlinux.bin cat armstub64.bin vmlinux.bin > vmlinux-stubbed.bin And then set kernel=vmlinux-stubbed.bin and copy my device tree blob ove...
by Electron752
Sat Apr 09, 2016 10:14 am
Forum: Bare metal, Assembly language
Topic: Boot 64bit linux without u-boot?
Replies: 5
Views: 2339

Re: Boot 64bit linux without u-boot?

More food for through. The kernel in both phases of boot don't need to be the same image. The memory copy is just an optimization. The second image could just as well be a different kernel completely or even a arm32 kernel image. This would allow using a 64 bit kernel as a bootloader for a 32 bit ke...
by Electron752
Sat Apr 09, 2016 8:24 am
Forum: Bare metal, Assembly language
Topic: Boot 64bit linux without u-boot?
Replies: 5
Views: 2339

Boot 64bit linux without u-boot?

I was thinking about what the value add of u-boot is, and I'm starting to get confused. What exactly is it needed for? Thought 1: Since u-boot is a stripped down version of the linux kernel, why does it need to be built from a completely seperate source tree? Why can't it just be "real" linux with a...
by Electron752
Sat Apr 09, 2016 7:10 am
Forum: Bare metal, Assembly language
Topic: Goodbye device tree, hello virtual bus!
Replies: 1
Views: 950

Goodbye device tree, hello virtual bus!

The first time I saw these device trees I always wondered what the purpose of them is. After trying to use them awhile, I've come to the conclusion that they are a total mess. What I'm thinking is that maybe the firmware/bootloader should just pass a very basic device tree to the kernel to keep the ...
by Electron752
Sat Apr 09, 2016 4:18 am
Forum: Bare metal, Assembly language
Topic: UBoot and FDT
Replies: 15
Views: 4861

Re: UBoot and FDT

I'll see if I can use these properties to override some of the missing command line arguments.
by Electron752
Sat Apr 09, 2016 3:58 am
Forum: Bare metal, Assembly language
Topic: UBoot and FDT
Replies: 15
Views: 4861

Re: UBoot and FDT

For reasons I don't totally understand, the linux kernel needs to have the mac address passed in from the bootloader as a kernel command line argument. Perhaps because it is stored at a eeprom location unavailable to the main CPU. The Pi's standard MAC address is not stored anywhere, as such. It is...
by Electron752
Sat Apr 09, 2016 3:42 am
Forum: Bare metal, Assembly language
Topic: UBoot and FDT
Replies: 15
Views: 4861

Re: UBoot and FDT

Or assuming that the firmware can be changed, the linux kernel could skip the command line argument and query from the firmware just like other properties are queried. It may actually be better that way then making it a command line argument.
by Electron752
Sat Apr 09, 2016 3:24 am
Forum: Bare metal, Assembly language
Topic: UBoot and FDT
Replies: 15
Views: 4861

Re: UBoot and FDT

Please moderator, i don't getting any answers from my questions at this thread. You maybe move this thread to more appropriate sub forum like Device tree. For reasons I don't totally understand, the linux kernel needs to have the mac address passed in from the bootloader as a kernel command line ar...
by Electron752
Fri Apr 08, 2016 4:48 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

HI, I tried getting the foundation kernel source to work in 64 bit, but I completely failed to get something to boot. I think too much is different in the way things are initialized between the two trees especially the IRQ handler code. I don't really know enough about the low layers of the architec...
by Electron752
Thu Apr 07, 2016 6:51 am
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

Hi all. After ponding for awhile, I've come to the conclusion that I'm doing this backward. Rather then try to copy the foundation files back into the upstream source, I think the better method is to start with the foundation source and attempt to merge in the small number of changes that were neede...
by Electron752
Thu Apr 07, 2016 3:13 am
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

Just thinking off the top of my head, perhaps a compromise would be to have both sets of drivers in the kernel image. I can certainly rename the driver ids to be difference. Then the end user or whoever can apply some kind of switch that activates one set for a desktop scenario or activates the othe...
by Electron752
Thu Apr 07, 2016 3:01 am
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

Assuming HDMI audio never makes it into the upstream source because of business reasons, the question becomes how important is HDMI audio. For embedded systems, servers, and IoT it probably isn't important at all. For Desktop users, it's probably critical. Since I already have an Intel PC and am mor...
by Electron752
Thu Apr 07, 2016 2:42 am
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

But I thought that the whole reason we have this issue is that companies like Broadcom want to keep parts of the chip hidden to protect IP. So I don't think the whole thing is every going to be completely open sourced without some kind of binary blob. Or at least not the whole things without some li...
by Electron752
Thu Apr 07, 2016 2:20 am
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

What does "Some of it has to do with configuration conflicts in the address space." mean, in detail? I don't see how there would be any difference between the 32-bit and 64-bit ports here as far as a standard kernel driver is concerned. Equally, FW-vs-not shouldn't influence anything here either. T...
by Electron752
Thu Apr 07, 2016 1:04 am
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

I started attempting to get sound to work, and boy did I hit a brick wall really really fast. I see now that we have two paths that are mutually exclusive and I think I'm only seeing the tip of it. The foundation has one view on the way things should work with the binary blob doing a bunch of things...
by Electron752
Wed Apr 06, 2016 8:13 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

Got archlinuxarm booting to 64 bit userland, thanks Electron752 Can you add CONFIG_DEVPTS_MULTIPLE_INSTANCES=y sometime please. Also what is your mkimage command as mine fail to boot Cool, I have some more changes pending as well. I might post a new version in a few days. I also found that a bunch ...
by Electron752
Wed Apr 06, 2016 5:24 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

It may also be good for supporting relatively closed source applications such as wolfgram/mathematica. They probably have no reason to recompile their application or want to deal with supporting 2 different architectures... Or supporting applications with hand optimized asm code. Since the RPI 3 has...
by Electron752
Wed Apr 06, 2016 4:57 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

Sorry it took so long. I had to download raspbian again. I'm happy to report that 32bit raspbian boots just fine with the 64bit boot environment and 64bit kernel. It took a very, very long time to boot up because the MMC driver needs alot of work but otherwise it works just fine including the x wind...
by Electron752
Wed Apr 06, 2016 2:30 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

BTW, I think the RPI 3 is fast enough to do software decoding. So hardware decoding is just icing on the cake. Well, not for 1080p video, which needs hardware support. For general access to gpu, then vchiq needs to work. Once that works (test with "vcgencmd version") then alsa audio, 3D, HW video d...
by Electron752
Wed Apr 06, 2016 2:25 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

Yeah. It is still too early to reach conclusions, but from your ffmpeg benchmarks, it might be no advantages of running a 64 bit kernel + 64 bit userland on the RPi 3, for video (2D/3D) related stuff. It might be even worse, like someone said, because of the bigger memory and memory bandwidth needs...
by Electron752
Wed Apr 06, 2016 1:56 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

BTW, I think the RPI 3 is fast enough to do software decoding. So hardware decoding is just icing on the cake.
by Electron752
Wed Apr 06, 2016 1:54 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

Rascas:

Sorry I missed your question. The answer is no. It's software only. I only have a dumb video frame buffer working. Everything is software only. I was able to play a DVD rip on the RPI 3 in 64 bit mode though with ffplay without any issues. I didn't try HD video yet.
by Electron752
Wed Apr 06, 2016 1:42 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

I might eventually look into it, but 3d video running on the RPI isn't that important to me right now. I don't play video games much anymore, mesa certainly support software 3d, and I think if you ssh into the rpi and use X window forwarding the application usually uses the 3d capability on the mach...
by Electron752
Wed Apr 06, 2016 12:15 pm
Forum: Bare metal, Assembly language
Topic: ffmpeg benchmark(armhf vs aarch64/64bit vs 32bit)
Replies: 4
Views: 3013

Re: ffmpeg benchmark(armhf vs aarch64/64bit vs 32bit)

If you can tell me which command line switches to use, I can certainly rerun the tests in both 32bit and 64bit modes. I didn't build either version of ffmpeg or libav. This is the precompiled version off of the lastest debian "sid" release.
by Electron752
Wed Apr 06, 2016 12:03 pm
Forum: Bare metal, Assembly language
Topic: Entering aarch64 execution state
Replies: 171
Views: 77801

Re: Entering aarch64 execution state

Maybe a stupid question, but does this kernel boot with the VC4 blob or the Eric Anholt open-source driver ? I have not tested it, but great job on getting the 64 bit kernel working. I'm not sure what you are referring to. It boots with the official foundation firmware(I think this is the VC4 blob)...

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