lgeek

9 ms·

31.
by lgeek 10y ago
> For general user applications, yeah, performance isn't that big of a deal. Maybe if you use recent, powerful machines and don't particularly care about energy efficiency. In my experience with less powerful machines, the appl
32.
by lgeek 10y ago
Looking at the RISC-V spec, you probably should be using the AUIPC instruction to address data in your .text, .data or .bss sections. As a bonus, your code becomes position-independent so you can actually use it in shared libraries. To use
33.
by lgeek 10y ago
> 32-bit fixed encoding makes the decoder simple, but creates the same load-store problem as on SPARC - hello non-existent, synthetic instructions! I'm not familiar with this. Could you explain the problem or point me in the right d
34.
by lgeek 10y ago
Well, it's definitely fast enough not to notice excessive latency in the terminal and to run simple applications, but the instructions are interpreted so expect a serious slowdown compared to recompiling or dynamically translating the
35.
by lgeek 10y ago
I can see some pretty strong effects (and false positives) from what seem to be TLB misses. On my system, on Firefox, the L2 size is not detected correctly if transparent huge pages are enabled, but on Chromium it is. I'd like to take
36.
by lgeek 10y ago
I'm not saying that he's necessarily dropped it or that it's okay for the CS rep to have accused him of that, but my 4+ year old Galaxy S3 has the same sort of bubbles in two corners on which it has been dropped so I get why
37.
by lgeek 10y ago
> we believe that the benefits of open source we enjoy in the software world can be applied to the hardware world In my opinion open source hardware IP has at least two major limitations compared to software, which make it significantly
38.
by lgeek 10y ago
Use higher airflow (including a larger nozzle) and lower temperature. The temperature calibration might be a bit off if the soldermask gets damaged by air at 300°C. Preheating, which has already been mentioned, also helps.
39.
The alternative 33C3 venue (join it if you didn't get a ticket)(reddit.com)
1 points by lgeek 10y ago|0 comments
40.
by lgeek 10y ago
Fair enough, some instructions have many variants. But I work with ARM assembly almost daily and I still wouldn't remember that, for example, 'VQRDMULH' is a real instruction and it stands for 'Vector Saturating Rounding
41.
by lgeek 10y ago
> Here's a handy heuristic: if somebody claims to know every x86-64 instruction (or even every x86-32 instruction), you can be at least 90% sure they're lying. I very much prefer ARM myself, but you can probably apply the same
42.
by lgeek 10y ago
> I never felt more like stabbing myself than when trying to cipher out exactly which immediate values are possible on ARM, and which are not. It depends if you're compiling for ARM or Thumb. The main rules are: ARM and 32-bit Thumb
43.
by lgeek 10y ago
I've collated the answers to some of the questions: * How often do you encounter encryption? The most common answer is 'often'. Germany does not collect this statistic. Czech Republic and Hungary: 'rarely', Latvia h
44.
by lgeek 10y ago
> Is there any ARM SOC yet that ARM has said can run Linux out of the box? That is not how this works. ARM doesn't design any SoCs sold to the general public. They design some specifications, such as the ARM architecture specs, a nu
45.
by lgeek 10y ago
The Samsung Chromebook Pro looks pretty promising (RR3399, 4GB DRAM, 2K screen), but it hasn't been officially released yet.
46.
by lgeek 10y ago
It's annoying there's no Free driver stack for the Mali GPUs, but pretty much all other ARM IP is supported just fine in mainline Linux. Calling it a 'sorry state of open source on ARM' seems disingenuous.
47.
by lgeek 10y ago
> specs are on-par with a 2-year old smartphone flagship Cortex-A53 is a low cost, energy efficient, slow, in-order implementation. I don't think it was ever used as the main core in a flagship smartphone. Something like a 2012 ODRO
48.
by lgeek 10y ago
It's not that in this case, this is plain binary translation and not cycle accurate emulation. QEMU is super slow on x-to-x translation as well (something like 8x to 80x slowdown). Its translator is inefficient (for the sake of portabi
49.
by lgeek 10y ago
And these guys ship an x86 to ARM DBT which they claim has significantly better performance: https://eltechs.com/product/exagear-desktop/ . I haven't tried it. QEMU is the slowest DBT system I'm aware of,
50.
by lgeek 10y ago
NVIDIA had about 5 different generations of Tegra before the K1 [1]. The A15-based K1 (T124) came before the Denver-based K1 (T132) AFAIK. Both are very nice and a clear improvement over the previous generations. Denver is a bit inconsisten
51.
by lgeek 10y ago
> If you really need performance, not only "in some benchmarks" then there is no alternative to Intel. Different microarchitectures perform better on different workloads, nothing new here. AMD's CMT works very well on cont
52.
by lgeek 10y ago
> The thinner the battery, the closer the positive and negative terminals are. Absolutely false. All lithium ion batteries are made of 4 paper thin layers: two electrodes and two separators. These are cut in narrow strips and folded on t
53.
by lgeek 10y ago
Hmm, what are the advantages of using this bootloader over U-Boot? Or is it simply that U-Boot doesn't support Ethernet or some other peripherals on the A64 SoC?
54.
by lgeek 10y ago
Hmm, I know the factory firmware can be reliably crashed by sending malformed data over the network. I wonder if there's a RCE hidden somewhere in there which might allow bootstrapping to Linux over the network.
55.
by lgeek 10y ago
Somewhat off topic, but I wish NVIDIA published more information about Denver's DBO and the reasoning behind some design decisions. For example the company line is to just generate 'decent code' and let the DBO take care of i
56.
by lgeek 10y ago
> Since ARM moved to ARMv8, I groaningly refer to v8 as "x86 v2" I'll have to disagree, I think ARM mostly did the right thing with the A64 instruction set. The AArch32 instruction sets were just getting ridiculous (just
57.
by lgeek 10y ago
I was wondering how come people suddenly started starring the repository. I'm around to answer questions if there are any.
58.
by lgeek 12y ago
I've tried to use blueproximity at some point (mostly for convenience because I sometimes forget to lock my screen), but the range of BT devices is too large for comfort. I could be anywhere in my flat or in the medium-sized open plan
59.
by lgeek 12y ago
I remember writing a script at some point to lock the screensaver in case of high acceleration or if the laptop is tilting by more than a few degrees. The idea was to lock it if was snatched (or just moved around). However, that would only
60.
by lgeek 12y ago
> And until android has fake permissions I won't install messenger. Cyanogenmod has Privacy Guard, which is pretty much that.

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