Linus Torvalds has just announced the release of Linux 6.9 on LKML: So Thorsten is still reporting a few regression fixes that haven’t made it to me yet, but none of them look big or worrisome enough to delay the release for another week. We’ll have to backport them when they get resolved and hit upstream. So 6.9 is now out, and last week has looked quite stable (and the whole release has felt pretty normal). Below is the shortlog for the last week, with the changes mostly being dominated by some driver updates (gpu and networking being the big ones, but “big” is still pretty small, and there’s various other driver noise in there too). Outside of drivers, it’s some filesystem fixes (bcachefs still stands out, but ksmbd shows up too), some late selftest fixes, and some core networking fixes. And I now have a more powerful arm64 machine […]
Polos CH32Vxx 32-bit RISC-V MCU boards starts at $1.99
XPU Labs, a subsidiary of AnalogLamb, has designed three inexpensive “Polos” development boards based on WCH CH32VXX RISC-V microcontrollers with pricing starting at just $1.99. The three development/breakout boards have the same form factor and only differ in the specific RISC-V MCU used with three parts selected: the 48 MHz CH32V003F4U6 microcontroller, the 144 MHz CH32V203F8P6 MCU, and the CH32V305FBP6 that’s similar to the former but add more memory (32KB) and flash (128KB). You can see also three boards side-by-side in the photo below along with the Amnos LinkE CH32Vxx debugger & programmer board. Polos CH32V003 Breakout Alef specifications: MCU – WCH CH32V003F4U6 QingKe 32-bit RISC-V2A microcontroller up to 48MHz with 2KB SRAM, 16KB Flash (QFN20 Package) USB – 1x Micro USB port I/Os – 2x 12-pin headers with Up to 18 GPIOs with external interrupt support 1x USART, 1x I2C, 1x SPI 10-bit ADC Debugging – 1-wire serial debug […]
CH32V003 RISC-V MCU gets $1.5 development board, open source GCC toolchain and flasher utility
When we first wrote about the 10-cent CH32V003 RISC-V MCU it was offered in a $7 development board and the closed-source MounRiver Studio IDE had to be used for programming. But things have improved since October 2022, and now, you can buy a CH32V003 board for as little as $1.5 plus shipping, and an open-source GCC toolchain and flasher/downloader are now available. Let’s have a look at the hardware first with the low-cost nanoCH32V003 development board featuring a 48 MHz CH32V003 RISC-V microcontroller with 2KB SRAM and 16KB flash, a USB Type-C port for power, a reset button, and two rows of headers for the GPIOs. MuseLab nanoCH32V003 specifications: MCU – WCH CH32V003F4U6 32-bit RISC-V2A microcontroller up to 48 MHz with 2KB SRAM, 16KB flash (QFN20 package) Expansion – 2x 11-pin headers with up to 18x GPIOs, 1x USART, 1x I2C, 1x SPI, 8-channel 10-bit ADC, 5V, 3.3V, GND Debugging […]
$6 Rtlduino RTL8720DN dual-band WiFi IoT board features 2.4/5GHz Wireless MCU
There are plenty of WiFi modules for the IoT market, but those usually work at 2.4 GHz only. This may be an issue in areas where the 2.4 GHz spectrum is overcrowded. But two years ago, we were pleased to see the Ameba Z2 board offering dual-band (2.4GHz and 5Ghz) WiFi thanks to Realtek RTL8720CM wireless MCU, and last year, we discovered B&T BW16 dual-band IoT module based on RTL8720DN sold for under $4 before shipping. If you like the cheap price of the module, but do not feel like creating your own baseboard, or soldering wires to the module, you’ll be glad to know Rtlduino RTL8720DN board offers an easy way to evaluate RTL8720DN dual-band WiFi (and Bluetooth LE 5.0) microcontroller as it is fitted with a B&T BW16 module and comes in a form factor similar to NodeMCU ESP8266 board. Rtlduino RTL8720DN board Specifications: B&T BW16 wireless module […]
How to Sandbox an arm64 GCC on aarch64 Hardware with armv7 Userspace
CNXSoft: Guest post by Blu about setting up arm64 toolchain on 64-bit Arm hardware running a 32-bit Arm (Armv7) rootfs. Life is short and industry progress is never fast enough in areas we care about. That’s an observation most of us are familiar with. One would think that by now most aarch64 desktops would be running arm64 environments, with multi-arch support when needed. Alas, as of late 2019, chromeOS on aarch64 is still shipping an aarch64 kernel and an armhf userspace. And despite the fine job by the good folks at chromebrew, an aarch64 chromeOS machine in dev mode ‒ an otherwise excellent road-warrior ride, is stuck with 32-bit armhf. Is that a problem, some may ask? Yes, it is ‒ aarch64 is the objectively better arm ISA outside of MCUs, from gen-purpose code to all kinds of ISA extensions, SIMD in particular. That shows in contemporary compiler support and […]
Linaro Connect San Diego 2019 Schedule – IoT, AI, Optimizations, Compilers and More
Linaro has recently released the full schedule of Linaro Connect San Diego 2019 that will take place on September 23-27. Even if you can’t attend, it’s always interested to check out the schedule to find out what interesting work is done on Arm Linux, Zephyr OS, and so on. So I’ve created my own virtual schedule with some of the most relevant and interesting sessions of the five-day event. Monday, September 23 14:00 – 14:25 – SAN19-101 Thermal Governors: How to pick the right one by Keerthy Jagadeesh, Software Engineer, Texas Instruments With higher Gigahertz and multiple cores packed in a SoC the need for thermal management for Arm based SoCs gets more and more critical. Thermal governors that define the policy for thermal management play a pivotal role in ensuring thermal safety of the device. Choosing the right one ensures the device performs optimally with in the thermal budget. […]
Embedded Linux Conference & Open Source Summit 2019 Schedule
In the last few years, I covered the Embedded Linux Conference and IoT Summit schedules since both were happening at the same time and in the same location. But the Linux Foundation have recently announced the Embedded Linux Conference will combine with the Open Source Summit, so the IoT Summit appears to have been phased out. The full schedule for the events taking place on August 21 – 23, 2019 at the Hilton San Diego Bayfront, USA, has also been released, so I’ll create a virtual schedule with some of the sessions most relevant to this blog. Wednesday August 21, 2019 11:30 – 12:05 – What’s New with U-Boot? by Simon Glass, Google LLC U-Boot is a widely used bootloader in embedded systems. Many users are unaware of the wide feature-set of U-Boot, particularly features added in the last few years. This talk aims to bring users (and prospective users) […]
Facebook BOLT Speeds Up Large x86 & ARM64 Binaries by up to 15%
Compilers like GCC OR LLVM normally do a good job at optimizing your code when processing your source code into assembly, and then binary format, but there’s still room for improvement – at least for larger binaries -, and Facebook has just released BOLT (Binary Optimization and Layout Tool) that has been found to reduce CPU execution time by 2 percent to 15 percent. The tool is mostly useful for binaries built from a large code base, with binary size over 10MB which are often too large to fit in instruction cache. The hardware normally spends lots of processing time getting an instruction stream from memory to the CPU, sometimes up to 30% of execution time, and BOLT optimizes placement of instructions in memory – as illustrated below – in order to address this issue also known as “instruction starvation”. BOLT works with applications built by any compiler, including the […]