While working on a project for the FRDM-K20D50M, I faced a problem: I was running out of SRAM for my application. The GNU linker reports: “section `.bss’ will not fit in region `m_data'”: š¦
bss will not fit in region m_data
But my device has 16 KByte of SRAM, and I knew I use much less than 10 KByte. So what is the problem? Continue reading
ā This article has been written for the version 4 of ĀµVision. There is an update for version 5 of ĀµVision here: “Using Keil Ī¼Vision 5 with Processor Expert“
The good thing with using ARM microcontroller is: there are plenty of tool choices. Even myself, I’m using multiple different tool chains. And while I’m heavily using Eclipse, there are non-Eclipse tool chains which have their advantages too.
The cool thing with CodeWarrior is that beside of Eclipse based, it comes with Processor Expert integrated. And I’m using Processor Expert a lot in my projects. But using Processor Expert does not mean I’m limited to CodeWarrior or Eclipse. So I can use CodeRed or IAR as tool chain with it. And this post is about using Processor Expert with the ĀµVision tool chain from Keil/ARM.
Keil uVision Splash Screen
Having many projects open the same time, and working on them in parallel is a challenge. Ok, the human brain is not built for multitasking, but I still try ;-). What I typically I end up in my Eclipse Problems View to have entries from multiple projects mixed up:
Problems View with Entries for multiple Projects
How to show it that I can fix the problems for ony project only, and not showing all problems from all projects?
I stumbled now twice over a problem, and only after a lot of head scratching (you should see my head now š ) I have found the cause (and solution) for it. In the hope that I can save the readers of this blog some time, here is what happened.
I described in earlier posts how to enable GNU build tools to generate hex/bin/S19 files, or to write the code size to the console view. That works fine for me. But then I received a project were obviously this does not work: even with the project settings configured properly, there is no S19 file, and no code size printed. What’s wrong?
Additional Tools in ARM GNU Eclipse Panel
Yesterday was a great day: The book “Software Engineering for Embedded Systems” finally arrived š :
Software Engineering for Embedded Systems
Why I’m excited about this? Because I had the honor to contribute a chapter to that book š
Usually I do *not* use floating point numbers in my projects. For this, I select ‘None’ during the project creation in CodeWarrior for MCU:
No Floating Point Selected
But what if I need to change my mind later? How to change such a ‘no-floating-point-needed’ project to one with floating point format support?
Freescale has released this week an updated version of CodeWarrior: version 10.4. I’m usually not switching a tools version in the middle of a university semester. Unless I see a real benefit, and the risk is low. Well, I have used it now for a few days, and I have decided to move my projects from 10.3 to 10.4. Why? Read on…
CW for MCU10.4
How many times have I seen this:
printf("Hello world!");
I have a strong opinion, and a rule for using printf():
“Do *not* use printf()!”
InĀ this tutorial I explored how to use printf(), and this tutorial is so generic that it works for any processor/microcontroller. That flexibility is because I’m using Processor Expert. In case Processor Expert shall not be used, then some tweaks are needed. Here I show what is needed to have printf() working with the FRDM-KL25Z board. I use the UART0 connected to OpenSDA USB CDC for this.
In “Code Size Information with gcc for ARM/Kinetis” I use an option in the ARM gcc tool chain for Eclipse to show me the code size:
Ā Ā textĀ Ā Ā Ā Ā dataĀ Ā Ā Ā Ā Ā bssĀ Ā Ā Ā Ā Ā decĀ Ā Ā Ā Ā Ā hexĀ Ā Ā filename Ā 0x1408Ā Ā Ā Ā Ā 0x18Ā Ā Ā Ā 0x81cĀ Ā Ā Ā Ā 7228Ā Ā Ā Ā Ā 1c3cĀ Ā Ā size.elf
I have been asked by a reader of this blog what these item numbers really mean. Especially: what the heck is ‘bss’???? š
MCU on Eclipse 