AnsweredAssumed Answered

Can not link FreeRTOS example project in MCUXpresso - LPC1756

Question asked by Gioele Sessa on Mar 6, 2019
Latest reply on Mar 12, 2019 by Gioele Sessa

Hello, I am trying to build the freertos_blinky example project on my LPC1756 with the MCUXpresso IDE.

(MCUXpresso IDE v10.3.0 [Build 2200] [2018-12-03])


The two "lpc_board_nxp_lpcxpresso_1769board" and "lpc_chip_175x_6x" libraries are correctly imported and linked, so that the build does not generate any error, even if the sources and headers are located in other projects of the same workspace.


Here I list all the operation I did:

  • Open MCUXpresso IDE in the "C:\Users\Public\FreeRTOS_test_WS" workspace folder
  • New project...
  • Under the preinstalled MCUs section, select LPC1756
  • LPCOpen - C Project
  • Project name: "FreeRTOS_test"
  • Import the "" (the only one available for the 17xx family)
  • From all the available projects, import "freertos_blinky", "lpc_board_nxp_lpcxpresso_1769" and "lpc_chip_175x_6x"
  • Link the board and chip projects to the current one
  • Build project, no errors


When trying to add the "FreeRTOS.h" file, the compiler says that this file can not be found.
So I tried to import all the sources and headers from the "freertos_blinky" to my project without any luck.
I then tried to move all those files and modify all the include paths to fix all the errors, until I get these ones:

  • alloc.c:(.text._Csys_alloc+0x12): undefined reference to `__sys_appexit'
  • fpprintf.c:(.text.printf+0x50): undefined reference to `__Ciob'
  • _writebuf.c:(.text._Cwritebuf+0x14): undefined reference to `__sys_flen'
  • _writebuf.c:(.text._Cwritebuf+0x28): undefined reference to `__sys_seek'
  • fseek.c:(.text.fseek+0x1c): undefined reference to `__sys_istty'
  • fseek.c:(.text.fseek+0x92): undefined reference to `__sys_flen'


What can I do to make the freertos_blinky project visible from mine?

Am I missing something? I can not find any guide that talks about MCUXpresso, FreeRTOS and LPC17xx at the same time.


I hope for your help.


Best regards, Gioele.