News - ARM releases Juno dev platform for 64-bit computing

[HEXUS]

Enables software developers to code for next-gen hardware.

Read more.

[HalloweenJack]

and with AMD shipping the Opteron A1100 dev kits - looking rather good

[chrestomanci]

Hmm, a number of unanswered questions, like a link to order from, the cost, and when the board will be shipped. The whole thing smells a bit like a press release launch, and nothing will actually be available for another few months.

However a bigger red flag is the linux kernel version. The press release said 3.10 that was released around a year ago. (3.15 is the most recent stable version and was released about a week ago). Releasing with such an old kernel suggests that ARM have not learnt the lesson of getting their kernel changes accepted into the mainline because if they had it would have been trivial to support the latest kernel version on this board.

Instead, I predict another rant from Linus Torvolds, and putting up with poor and out of date support for this hardware as is sadly all too common with ARM dev boards.

[DanceswithUnix]

Hmm, a number of unanswered questions, like a link to order from, the cost, and when the board will be shipped. The whole thing smells a bit like a press release launch, and nothing will actually be available for another few months.

However a bigger red flag is the linux kernel version. The press release said 3.10 that was released around a year ago. (3.15 is the most recent stable version and was released about a week ago). Releasing with such an old kernel suggests that ARM have not learnt the lesson of getting their kernel changes accepted into the mainline because if they had it would have been trivial to support the latest kernel version on this board.

Instead, I predict another rant from Linus Torvolds, and putting up with poor and out of date support for this hardware as is sadly all too common with ARM dev boards.

It is just a dev board, so cost will be high and only available to companies who bulk buy ARM chips. If you buy enough chips, you can probably blag one for free. These things are designed to speed engineers getting a design to market, and hence speed silicon getting sold, they aren't intended to be usable as a product.

The PCIe options on the board look interesting, but in the configuration shown that looks like an Android dev kit.

My phone seems to be on 3.1.10 for Android 4.2, embedded devices aren't normally so worried about keeping up with the latest as a well understood version is often seen as better.

Edit to add: Something cheaper than the Zotac board would be nice: http://www.maplin.co.uk/p/zotac-jets...oper-kit-a30ny

[HalloweenJack]

http://community.arm.com/groups/smar...t-kit-from-amd


^^

the AMD kit allrady out

btw I can see why they are using the STABLE 3.10 kernel - 3.15 is buggy and needing a few fixes

[chrestomanci]

It is just a dev board, so cost will be high and only available to companies who bulk buy ARM chips. If you buy enough chips, you can probably blag one for free. These things are designed to speed engineers getting a design to market, and hence speed silicon getting sold, they aren't intended to be usable as a product.

I am not expecting to buy one from PC world for £30, but in my experience if an SOC company is serous about getting their platform out their, they do make sure that the dev kit is available to buy at reasonable cost by anyone who wants one. This usually means less than $500 either direct or from someone like Farnell components.

My phone seems to be on 3.1.10 for Android 4.2, embedded devices aren't normally so worried about keeping up with the latest as a well understood version is often seen as better.

I think you miss my point. The issue is not if the board comes with the latest (possibly unstable) kenel version, but if it is possible to buld a recent kernel for it. Older kernels are well understood, but they also have bugs that are fixed in newer kernels, as they lack features that the newer kernels have, so sooner or later it will be necessary to update. Doing so will be very easy if the kernel patches necessary to support this board have been accepted upstream, or very hard if not.

To explain the situation a bit more: In the x86 world, our PCs have a BIOS, which insulates the OS from needing to know hardware specific details like memory voltages & timings, and provides an easy way to discover an enumerate what hardware is present such as how much memory, how many CPUs, and what PCI cards are available. The outcome is that a Linux kernel built for x86 will boot on anything from a 30 year old 386, to the latest desktop from PC world. (And but for minimum system requirements, so will a windows kernel).

In the embedded ARM world, devices usually don't have a firmware to insulate the kernel from hardware details, so lots of stuff like memory timings has to be complied into the kernel, so you need a different kernel binary for every different ARM device, and a different set of patches and board configuration files in the kernel source tree as well. A few years ago, the situation got insane with the number of different devices that had config files in the main Linux kernel source (most of which where unmaintained) that the kernel maintainers called a halt and stopped accepting those patches.

The new system is know as device tree. The idea is that for each different ARM device, a device tree file listing all the hardware details is prepared. The kernel reads it early in the bootup process, and uses it to setup the hardware and find all the devices. Using device tree, the same kernel will work on most devices, and as the kernel is updated with bug fixes and new features the new kernel will still work because everything is independent.

The problem is that ARM SOC vendors have been slow to support device tree. Without it they can ship an ARM kernel, but that kernel will be abandonware from day one, as it is very unlikely to get bug fixes and new features that the rest of the Linux world gets. That is why I am concerned that the linux kernel that comes with this new 64 bit ARM board is old, and disappointed that ARM are not working with the Linux kernel community.

[DanceswithUnix]

The problem is that ARM SOC vendors have been slow to support device tree. Without it they can ship an ARM kernel, but that kernel will be abandonware from day one, as it is very unlikely to get bug fixes and new features that the rest of the Linux world gets. That is why I am concerned that the linux kernel that comes with this new 64 bit ARM board is old, and disappointed that ARM are not working with the Linux kernel community.

Thanks, most enlightening. ARM must be about the only cpu I haven't used in an embedded device (yet) so I wasn't aware of how broken that was. I had assumed that as most ARM chips seemed to have a secure boot loader, you would set up things like ram timings there. I can see with things like closed source graphics drivers that could take a while to straighten out.

There are 64 bit ARM dev boards for server use, that might be more like you are looking for. As I said, if I was running Android (which I am convinced the board here is aimed at) I would expect to run an Android approved kernel, but if I am running server code then I want to see up to date *everything*.

I see that AMD board runs Fedora, so that should have the same kernel version as their x86 distributions unless they want all sorts of integration shenanigans.