arm
How to measure program execution time in ARM Cortex-A8 processor?
Accessing the performance counters isn’t difficult, but you have to enable them from kernel-mode. By default the counters are disabled. In a nutshell you have to execute the following two lines inside the kernel. Either as a loadable module or just adding the two lines somewhere in the board-init will do: /* enable user-mode access … Read more
What is the difference between a Bootrom vs bootloader on ARM systems
Here’s how I understand the terms. Bootrom Bootrom (or Boot ROM) is a small piece of mask ROM or write-protected flash embedded inside the processor chip. It contains the very first code which is executed by the processor on power-on or reset. Depending on the configuration of some strap pins or internal fuses it may … Read more
Is it redundant to check if a modulo operation is needed, then performing it?
If you want to understand what the compiler is doing, you’ll need to just pull up some assembly. I recommend this site (I already entered code from the question)): https://godbolt.org/g/FwZZOb. The first example is more interesting. int div(unsigned int num, unsigned int num2) { if( num >= num2 ) return num % num2; return num; … Read more
what’s ARM TCM memory
TCM, Tightly-Coupled Memory is one (or multiple) small, dedicated memory region that as the name implies is very close to the CPU. The main benefit of it is, that the CPU can access the TCM every cycle. Contrary to the ordinary memory there is no cache involved which makes all memory accesses predictable. The main … Read more
Can ARM desktop programs be built using visual studio 2012?
You can edit the file: C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V110\Platforms\ARM\Microsoft.Cpp.ARM.Common.props In the <PropertyGroup> section add the line: <WindowsSDKDesktopARMSupport>true</WindowsSDKDesktopARMSupport> before </PropertyGroup> And that’s all, you can build ARM desktop apps with VS2012.
Tool to visualize the device tree file (dtb) used by the Linux kernel? [closed]
dtc -O dts sudo apt-get install device-tree-compiler dtc -I dtb -O dts -o a.dts a.dtb gives a well indented textual representation of the device tree a.dtb, which is easy to understand with a text editor. Or dump it to stdout with: dtc -I dtb -O dts -o – a.dtb The source code for dtc is … Read more
Why ARM NEON not faster than plain C++?
The NEON pipeline on Cortex-A8 is in-order executing, and has limited hit-under-miss (no renaming), so you’re limited by memory latency (as you’re using more than L1/L2 cache size). Your code has immediate dependencies on the values loaded from memory, so it’ll stall constantly waiting for memory. This would explain why the NEON code is slightly … Read more
Windows -1252 is not supported encoding name
From a .NET Core 2.2 project, I had to install via Nuget the following two packages: (System.Text.Encoding & System.Text.Encoding.CodePages) Then you have to set it before the use of libraries: using System.Text; … { Encoding.RegisterProvider(CodePagesEncodingProvider.Instance); … }