Hello,
I want to create a unsecure secondary bootloader and want to save some byte between software reset. It seams that the location 0x20000000..0x20010000 is changed during this reset. I stoped in ResetISR() and the Debugger show different values. So it is not the clib, that initialize the data. It seams the LPC internal bootloader.
The reset is NVIC_SystemReset().
Is there a location, where I can use some Bytes that do note change? At the best a location for the hole LPC55xx family.
I use the MCU xpresso IDE and the LPC55S16-EVK at the moment. I checked the memory using the Memory window of the IDE.
Hello steffenrose,
How about place the data in specific memory region, refer to MCUXpesso IDE User Guide:
Thank you very much. My question was related a specific memory location. Now I learnd, that the Boot Rom use a lot. This memory is not suitable to save values during a software reset,
I think the MCUXpresso autogenerated linker scripts should prevent this location to use for the noinit sections.
Currently I use a different way.
I set a offset for the Stack location and create a section at the end using
--section-start=command=0x2000FFF0
Thats why I want, that our end customer can use the Managed linker scripts for different derivates.
Unattractive is, that objcopy use it for ihex and binary generation like the text section.
Sections:
Idx Name Size VMA LMA File off Algn
0 .sec1 00008000 00008000 00008000 00000000 2**0
CONTENTS, ALLOC, LOAD
1 .sec2 00007770 00010000 00010000 00016811 2**0
CONTENTS, ALLOC, LOAD
2 .sec3 00000010 2000fff0 2000fff0 0002b82b 2**0
CONTENTS, ALLOC, LOAD
Hello steffenrose,
Thanks for your sharing, I will take a ticket to MCUXpresso development team about your this suggestion:" I think the MCUXpresso autogenerated linker scripts should prevent this location to use for the noinit sections."
BR
Alice