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Category Archives: CMSIS
User I/O from mbed with CMSIS-DAP
Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Latest posts by Niall Cooling (see all)
- Navigating Memory in C++: A Guide to Using std::uintptr_t for Address Handling - February 22, 2024
- Embedded Expertise: Beyond Fixed-Size Integers; Exploring Fast and Least Types - January 15, 2024
- Disassembling a Cortex-M raw binary file with Ghidra - December 20, 2022
Following on from my last posting regarding using native C/C++ on the mbed I have found that I currently cannot get output via the standard CMSIS ITM_SendChar function as used in the Cortex-M hard fault handler (I am currently in dialog with the guys at ARM trying to resolve this).
In the standard mbed environment, the mbed can communicate with a host PC through a “USB Virtual Serial Port” over the same USB cable that is used for programming using printf(), e.g.
#include “mbed.h”
int […]
Posted in ARM, C/C++ Programming, CMSIS, Cortex
3 Comments
Native C/C++ Application development for the mbed using CMSIS-DAP
Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Latest posts by Niall Cooling (see all)
- Navigating Memory in C++: A Guide to Using std::uintptr_t for Address Handling - February 22, 2024
- Embedded Expertise: Beyond Fixed-Size Integers; Exploring Fast and Least Types - January 15, 2024
- Disassembling a Cortex-M raw binary file with Ghidra - December 20, 2022
If you have been following the Feabhas blog for some time, you may remember that in April of last year I posted about my experiences of using the MQTT protocol. The demonstration code was ran the ARM Cortex-M3 based mbed platform.
For those that are not familiar with the mbed, it is an “Arduino-like” development platform for small microcontroller embedded systems. The variant I’m using is built using an NXP LPC1768 Cortex-M3 device, which offers a plethora of connection options, ranging […]
Posted in ARM, C/C++ Programming, CMSIS, Cortex
Tagged ARM, C Declarations, C++, CMSIS, Cortex-M3, Keil, LPC1768, mbed
2 Comments
Setting up the Cortex-M3/4 (ARMv7-M) Memory Protection Unit (MPU)
Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Latest posts by Niall Cooling (see all)
- Navigating Memory in C++: A Guide to Using std::uintptr_t for Address Handling - February 22, 2024
- Embedded Expertise: Beyond Fixed-Size Integers; Exploring Fast and Least Types - January 15, 2024
- Disassembling a Cortex-M raw binary file with Ghidra - December 20, 2022
An optional part of the ARMv7-M architecture is the support of a Memory Protection Unit (MPU). This is a fairly simplistic device (compared to a fully blow Memory Management Unit (MMU) as found on the Cortex-A family), but if available can be programmed to help capture illegal or dangerous memory accesses.
When first looking at programming the MPU it may seem rather daunting, but in reality it is very straightforward. The added benefit of the ARMv7-M family is the well-defined memory […]
Posted in ARM, C/C++ Programming, CMSIS, Cortex, Testing
Tagged C Declarations, CMSIS, LPC1768, MPU
12 Comments
Developing a Generic Hard Fault handler for ARM Cortex-M3/Cortex-M4
Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Latest posts by Niall Cooling (see all)
- Navigating Memory in C++: A Guide to Using std::uintptr_t for Address Handling - February 22, 2024
- Embedded Expertise: Beyond Fixed-Size Integers; Exploring Fast and Least Types - January 15, 2024
- Disassembling a Cortex-M raw binary file with Ghidra - December 20, 2022
This posting assumes you that you have a working ARM Cortex-M3 base project in Keil uVision. If not, please see the “howto” video: Creating ARM Cortex-M3 CMSIS Base Project in uVision
Divide by zero error
Given the following C function
int div(int lho, int rho)
{
return lho/rho;
}
called from main with these arguments
int main(void)
{
int a = 10;
int b = 0;
int c;
c = div(a, b);
// other code
}
You […]
Posted in ARM, C/C++ Programming, CMSIS, Cortex
Tagged ARM, C Programming, CMSIS, Cortex-M
24 Comments
Weak linkage in C programming
Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Latest posts by Niall Cooling (see all)
- Navigating Memory in C++: A Guide to Using std::uintptr_t for Address Handling - February 22, 2024
- Embedded Expertise: Beyond Fixed-Size Integers; Exploring Fast and Least Types - January 15, 2024
- Disassembling a Cortex-M raw binary file with Ghidra - December 20, 2022
When linking C programs there are (in general) only a couple of errors you’re likely to see. If, for example, you have two functions in different files, both with external linkage, then the files will compile okay, but when you link you’ll likely see an error along these lines:
linking…
weak_linkage.axf: Error: L6200E: Symbol foo multiply defined (by foo.o and foo2.o).
Target not created
Most of the time this makes sense and is as expected; however there is a particular instance where it gets in the […]
Embedded System Conference – India
Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Latest posts by Niall Cooling (see all)
- Navigating Memory in C++: A Guide to Using std::uintptr_t for Address Handling - February 22, 2024
- Embedded Expertise: Beyond Fixed-Size Integers; Exploring Fast and Least Types - January 15, 2024
- Disassembling a Cortex-M raw binary file with Ghidra - December 20, 2022
This year I have honour of being invited to present at the Embedded Systems Conference in Bengaluru (Bangalore), India. Based on previous visits these classes are very well attended and always generate a lot of post-class discussions.
This year I’ve extended my previous 1/2 day class to a full day titled “Programming in C for the ARM Cortex-M Microcontroller”. Having a full day allows me to delve in too much greater detail. The class is broken down in to four subsections:
Cortex-M Architecture
C […]
CMSIS-RTOS Presentation
Director at Feabhas Limited
Co-Founder and Director of Feabhas since 1995.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Niall has been designing and programming embedded systems for over 30 years. He has worked in different sectors, including aerospace, telecomms, government and banking.
His current interest lie in IoT Security and Agile for Embedded Systems.
Latest posts by Niall Cooling (see all)
- Navigating Memory in C++: A Guide to Using std::uintptr_t for Address Handling - February 22, 2024
- Embedded Expertise: Beyond Fixed-Size Integers; Exploring Fast and Least Types - January 15, 2024
- Disassembling a Cortex-M raw binary file with Ghidra - December 20, 2022
I have finally finished and sent off my presentation for next weeks Hitex one-day ARM User Conferences titled “ARM – the new standard across the board?” at the National Motorcycle Museum in Solihull.
Back in February, at the embeddedworld exhibition and conference in Nuremberg, Germany, ARM announced the latest version (version 3) of the Cortex(tm) Microcontroller Software Interface Standard (CMSIS). The major addition is the introduction of an abstraction layer for Real-Time Operating Systems (RTOS).
The presentation I’m giving explains; what […]