BBC Microbit fails to build

[fduignan]

Description

Using the cloud based compiler on mbed.com Mbed Revision 170:e95d106 fails to compile even basic blinky for BBC Microbit with the following error:
Error: Undefined symbol __heap_base (referred from /opt/armcc5_06_u3/bin/../lib/armlib/mc_p.l(malloc.o)).
Info: Unable to download. Fix the reported errors...

The compiler reports a version number of 1.10.18.0
The earlier mbed version : 169:a7c7b63 works fine

Issue request type

[ ] Question
[ ] Enhancement
[X] Bug

[0xc0170]

Looking at the recent changes to the target directory, I suspect this is caused by recent changes to the boot process. Here's the file that is requesting that symbol https://github.com/ARMmbed/mbed-os/blob/88eb8aab2330c9ab2b8948079f123ba4b777224a/rtos/TARGET_CORTEX/TOOLCHAIN_ARM_MICRO/mbed_boot_arm_micro.c

I can't find the __heap_base in the startup file for MCU_NRF51_16K_BASE targets

@c1728p9 Please review
[Mirrored to Jira]

[fduignan]

As of today, the online mbed for the bbc microbit appears to be completely borked. Compiling the basic blinky results in:
Error: The build system did not finish successfully. Error number -230.
Previously working programs (presumably with older library versions) compile successfully but appear to crash during boot.
I have not yet managed to successfully select an older library and compile a project.
Help?

[Mirrored to Jira]

[fduignan]

More information: I'm suspecting an incorrect linker script in the online mbed compiler setup.
If I look at the (Intel) Hex file output from the compiler for a new program I seen entries like this:
:020000040001F9
:108000000040002099810100AB810100AD81010099
If I look at the hex output for a file I compiled a week or so ago I see this:
:020000040000FA
:10000000C0070000D1060000D1000000B1060000CA
This indicates that the linker is outputting code for a different address range today (8000) compared to a week or so ago (0000).
Can someone verify and fix please?
[Mirrored to Jira]

[0xc0170]

The latest report is another issue (linker issue?). Looking at the history of files for microbit (https://github.com/ARMmbed/mbed-os/tree/master/targets/TARGET_NORDIC/TARGET_MCU_NRF51822) no change for some time. Neither in the target definition (targets.json) file.

I would suspect a change in tools rather
[Mirrored to Jira]

[0xc0170]

@c1728p9 Can you review __heap_base heap base error?
[Mirrored to Jira]

[theotherjimmy]

#8305 fixes this for the next release. The current release won't build.

[adbridge]

Internal Jira reference: https://jira.arm.com/browse/IOTHAL-351