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Part Number: TMDS64EVM
When compiling and linking C code for the PRU, I am getting an undefined symbol linker error, missing definition for symbol "__pruabi_remu", caused by the conditional statement in the code block:
if(framecount % 1000 == 0)
{
*PRU1_MINOR_FRAME_CNT = framecount;
}
From what I've seen, I am missing some library file that is required, "pruaib" or something similar, but can not find anythign like it in my installation or online. Any suggestions on where to find it?
Hi
Can you please share the makefile, or the linker command you are using?
Regards
Dhaval
I am using a linker file from the SDK examples, and the makefile is autogenerated by CCS when I build, but here they are attached. (I changed the file extenstion so the E2E forum would let me upload them)
################################################################################ # Automatically-generated file. Do not edit! ################################################################################ SHELL = cmd.exe CG_TOOL_ROOT := C:/ti/ti_cgt_pru_2.3.3 GEN_OPTS__FLAG := GEN_CMDS__FLAG := ORDERED_OBJS += \ "./PRU_AFDX.obj" \ "./PRU_Clocks.obj" \ "./PRU_MDIO.obj" \ "./PRU_PCFG.obj" \ "./PRU_RGMII.obj" \ "./PRU_RegisterConfig.obj" \ "./PRU_Scheduler.obj" \ "./PRU_TaskManager.obj" \ "./PRU_Timer.obj" \ "./boot.obj" \ "./main.obj" \ "../linker.cmd" \ $(GEN_CMDS__FLAG) \ -include ../makefile.init RM := DEL /F RMDIR := RMDIR /S/Q # All of the sources participating in the build are defined here -include sources.mk -include subdir_vars.mk -include subdir_rules.mk -include objects.mk ifneq ($(MAKECMDGOALS),clean) ifneq ($(strip $(C55_DEPS)),) -include $(C55_DEPS) endif ifneq ($(strip $(C_UPPER_DEPS)),) -include $(C_UPPER_DEPS) endif ifneq ($(strip $(S67_DEPS)),) -include $(S67_DEPS) endif ifneq ($(strip $(S62_DEPS)),) -include $(S62_DEPS) endif ifneq ($(strip $(S_DEPS)),) -include $(S_DEPS) endif ifneq ($(strip $(OPT_DEPS)),) -include $(OPT_DEPS) endif ifneq ($(strip $(C??_DEPS)),) -include $(C??_DEPS) endif ifneq ($(strip $(ASM_UPPER_DEPS)),) -include $(ASM_UPPER_DEPS) endif ifneq ($(strip $(S??_DEPS)),) -include $(S??_DEPS) endif ifneq ($(strip $(C64_DEPS)),) -include $(C64_DEPS) endif ifneq ($(strip $(CXX_DEPS)),) -include $(CXX_DEPS) endif ifneq ($(strip $(S64_DEPS)),) -include $(S64_DEPS) endif ifneq ($(strip $(INO_DEPS)),) -include $(INO_DEPS) endif ifneq ($(strip $(CLA_DEPS)),) -include $(CLA_DEPS) endif ifneq ($(strip $(S55_DEPS)),) -include $(S55_DEPS) endif ifneq ($(strip $(SV7A_DEPS)),) -include $(SV7A_DEPS) endif ifneq ($(strip $(C62_DEPS)),) -include $(C62_DEPS) endif ifneq ($(strip $(C67_DEPS)),) -include $(C67_DEPS) endif ifneq ($(strip $(PDE_DEPS)),) -include $(PDE_DEPS) endif ifneq ($(strip $(K_DEPS)),) -include $(K_DEPS) endif ifneq ($(strip $(C_DEPS)),) -include $(C_DEPS) endif ifneq ($(strip $(CC_DEPS)),) -include $(CC_DEPS) endif ifneq ($(strip $(C++_DEPS)),) -include $(C++_DEPS) endif ifneq ($(strip $(C43_DEPS)),) -include $(C43_DEPS) endif ifneq ($(strip $(S43_DEPS)),) -include $(S43_DEPS) endif ifneq ($(strip $(ASM_DEPS)),) -include $(ASM_DEPS) endif ifneq ($(strip $(S_UPPER_DEPS)),) -include $(S_UPPER_DEPS) endif ifneq ($(strip $(CPP_DEPS)),) -include $(CPP_DEPS) endif ifneq ($(strip $(SA_DEPS)),) -include $(SA_DEPS) endif endif -include ../makefile.defs # Add inputs and outputs from these tool invocations to the build variables EXE_OUTPUTS += \ ICSSG1_PRU0_AFDX.out EXE_OUTPUTS__QUOTED += \ "ICSSG1_PRU0_AFDX.out" # All Target all: $(OBJS) $(CMD_SRCS) $(GEN_CMDS) @$(MAKE) --no-print-directory -Onone "ICSSG1_PRU0_AFDX.out" # Tool invocations ICSSG1_PRU0_AFDX.out: $(OBJS) $(CMD_SRCS) $(GEN_CMDS) @echo 'Building target: "$@"' @echo 'Invoking: PRU Linker' "C:/ti/ti_cgt_pru_2.3.3/bin/clpru" -v4 -O0 --define=SOC_AM64X --define=_DEBUG_=1 --define=PRU0 --define=SLICE1 -g --diag_warning=225 --diag_wrap=off --display_error_number --endian=little -z -m"abi=ti" --heap_size=0x100 --stack_size=0x200 --disable_auto_rts --diag_suppress=10063-D --diag_wrap=off --display_error_number --warn_sections --xml_link_info="ICSSG1_PRU0_AFDX_linkInfo.xml" --entry_point=_c_int00_noinit_noargs --ram_model -o "ICSSG1_PRU0_AFDX.out" $(ORDERED_OBJS) @echo 'Finished building target: "$@"' @echo ' ' @$(MAKE) --no-print-directory post-build # Other Targets clean: -$(RM) $(EXE_OUTPUTS__QUOTED) -$(RM) "PRU_AFDX.obj" "PRU_Clocks.obj" "PRU_MDIO.obj" "PRU_PCFG.obj" "PRU_RGMII.obj" "PRU_RegisterConfig.obj" "PRU_Scheduler.obj" "PRU_TaskManager.obj" "PRU_Timer.obj" "boot.obj" "main.obj" -$(RM) "PRU_AFDX.d" "PRU_Clocks.d" "PRU_MDIO.d" "PRU_PCFG.d" "PRU_RGMII.d" "PRU_RegisterConfig.d" "PRU_Scheduler.d" "PRU_TaskManager.d" "PRU_Timer.d" "boot.d" "main.d" -@echo 'Finished clean' -@echo ' ' post-build: -$(CG_TOOL_ROOT)/bin/hexpru --diag_wrap=off --array --array:name_prefix=PRU1Firmware -o pru1_load_bin.h ICSSG1_PRU0_AFDX.out -if win32 == linux cat C:/ti/mcu_plus_sdk_am64x_11_02_00_24/source/pru_io/firmware/pru_load_bin_copyright.h pru1_load_bin.h > C:/Users/seth.appleman/workspace_v12/open-pru/examples/empty_c/firmware/am64x-evm/pru1_load_bin.h -if win32 == linux rm pru1_load_bin.h -if win32 == win32 $(CCS_INSTALL_DIR)/utils/cygwin/cat C:/ti/mcu_plus_sdk_am64x_11_02_00_24/source/pru_io/firmware/pru_load_bin_copyright.h pru1_load_bin.h > C:/Users/seth.appleman/workspace_v12/open-pru/examples/empty_c/firmware/am64x-evm/pru1_load_bin.h -if win32 == win32 $(CCS_INSTALL_DIR)/utils/cygwin/rm pru1_load_bin.h -@echo ' ' .PHONY: all clean dependents .SECONDARY: -include ../makefile.targets
/*
* AM64x_PRU0.cmd
*
* Example Linker command file for linking programs built with the C compiler
* on AM64x PRU0 cores
*/
-cr /* Link using C conventions */
/* Specify the System Memory Map */
MEMORY
{
PAGE 0:
/* 12 KB PRU Instruction RAM */
PRU_IMEM : org = 0x00000000 len = 0x00003000
PAGE 1:
/* Data RAMs */
/* 8 KB PRU Data RAM 0; use only the first 4 KB for PRU0 and reserve
* the second 4 KB for RTU0 and Tx_PRU0 */
PRU0_DMEM_0 : org = 0x00000000 len = 0x00001000 CREGISTER=24
/* 8 KB PRU Data RAM 1; reserved completely for Slice1 cores - PRU1,
* RTU1 and Tx_PRU1; do not use for any Slice0 cores */
PRU0_DMEM_1 : org = 0x00002000 len = 0x00001000 CREGISTER=25
/* NOTE: Custom split of the second 4 KB of ICSS Data RAMs 0 and 1
* split equally between the corresponding RTU and Tx_PRU cores in
* each slice */
RTU0_DMEM_0 : org = 0x00001000 len = 0x00000800
TX_PRU0_DMEM_0 : org = 0x00001800 len = 0x00000800
RTU0_DMEM_1 : org = 0x00003000 len = 0x00000800
TX_PRU0_DMEM_1 : org = 0x00003800 len = 0x00000800
PAGE 2:
/* C28 needs to be programmed to point to SHAREDMEM, default is 0 */
/* 64 KB PRU Shared RAM */
PRU_SHAREDMEM : org = 0x00010000 len = 0x00010000 CREGISTER=28
/* Internal Peripherals */
/* NOTE: Use full INTC length instead of 0x200 to match the pruIntc
* structure definition in pru_intc.h, ignoring the second Constant
* Register #6 that starts at 0x200 offset within INTC */
PRU_INTC : org = 0x00020000 len = 0x00001504 CREGISTER=0
PRU_IEP1 : org = 0x0002F000 len = 0x00000100 CREGISTER=1
PRU_IEP1_0x100 : org = 0x0002F100 len = 0x0000021C CREGISTER=2
PRU_ECAP : org = 0x00030000 len = 0x00000060 CREGISTER=3
PRU_CFG : org = 0x00026000 len = 0x00000100 CREGISTER=4
PRU_CFG_0x100 : org = 0x00026100 len = 0x00000098 CREGISTER=5
/* XXX: PRU_INTC_0x200 is part of INTC space, and is therefore commented
* out as it conflicts with PRU_INTC size above. To use PRU_INTC_0x200,
* split up the pruIntc structure and CT_INTC variable in
* source/include/c_code/PROCESSOR/pru_intc.h */
/*PRU_INTC_0x200: org = 0x00020200 len = 0x00001304 CREGISTER=6*/
PRU_UART : org = 0x00028000 len = 0x00000038 CREGISTER=7
PRU_IEP0_0x100 : org = 0x0002E100 len = 0x0000021C CREGISTER=8
MII_G_RT : org = 0x00033000 len = 0x00000F44 CREGISTER=9
TM_CFG_PRU0 : org = 0x0002A000 len = 0x0000004C CREGISTER=10
PRU0_CTRL : org = 0x00022000 len = 0x00000030 CREGISTER=11
PA_STATS_QRAM : org = 0x00027000 len = 0x00001000 CREGISTER=12
PA_STATS_CRAM : org = 0x0002C000 len = 0x00001000 CREGISTER=13
MII_MDIO : org = 0x00032400 len = 0x00000088 CREGISTER=21
PRU_RTU_RAT0 : org = 0x00008000 len = 0x00000854 CREGISTER=22
PRU_IEP0 : org = 0x0002E000 len = 0x00000100 CREGISTER=26
MII_RT : org = 0x00032000 len = 0x00000070 CREGISTER=27
/* External Regions */
/* Random length 0x100 assigned to the below regions */
RSVD14 : org = 0x00024800 len = 0x00000100 CREGISTER=14
RSVD15 : org = 0x60000000 len = 0x00000100 CREGISTER=15
RSVD16 : org = 0x70000000 len = 0x00000100 CREGISTER=16
RSVD17 : org = 0x80000000 len = 0x00000100 CREGISTER=17
RSVD18 : org = 0x90000000 len = 0x00000100 CREGISTER=18
RSVD19 : org = 0xA0000000 len = 0x00000100 CREGISTER=19
RSVD20 : org = 0xB0000000 len = 0x00000100 CREGISTER=20
RSVD23 : org = 0xC0000000 len = 0x00000100 CREGISTER=23
/* Random length 0x10000 (max len value) assigned to programmable C29-31*/
RSVD29 : org = 0xD0000000 len = 0x00010000 CREGISTER=29
RSVD30 : org = 0xE0000000 len = 0x00010000 CREGISTER=30
RSVD31 : org = 0xF0000000 len = 0x00010000 CREGISTER=31
}
/* Specify the sections allocation into memory */
SECTIONS {
/* Forces _c_int00 to the start of PRU IRAM. Not necessary when loading
an ELF file, but useful when loading a binary */
.text:_c_int00* > 0x0, PAGE 0
.text > PRU_IMEM, PAGE 0
.stack > PRU0_DMEM_0, PAGE 1
.bss > PRU0_DMEM_0, PAGE 1
.cio > PRU0_DMEM_0, PAGE 1
.data > PRU0_DMEM_0, PAGE 1
.switch > PRU0_DMEM_0, PAGE 1
.sysmem > PRU0_DMEM_0, PAGE 1
.cinit > PRU0_DMEM_0, PAGE 1
.rodata > PRU0_DMEM_0, PAGE 1
.rofardata > PRU0_DMEM_0, PAGE 1
.farbss > PRU0_DMEM_0, PAGE 1
.fardata > PRU0_DMEM_0, PAGE 1
}
Hi
I apologize for the delayed response here.
"--disable_auto_rts" flag prevents the linker from automatically pulling in the PRU runtime support library (libc.a), which contains __pruabi_remu and other arithmetic helper functions. Without this library, any C operation that requires runtime support will produce an undefined symbol error.
Option A — Remove --disable_auto_rts (simplest)
In your CCS project's linker settings, remove the --disable_auto_rts flag unless, it is added for any specific reason. This lets the linker automatically find and link the correct runtime library from your PRU compiler installation.
Option B — Manually link libc.a
If you need --disable_auto_rts for other reasons, explicitly add the runtime library to your linker command by adding -llibc.a to the linker flags. Using the generic name libc.a allows the linker to automatically select the correct library variant for your build configuration.
In CCS, you can add this under Project Properties → Build → PRU Linker → File Search Path → Include library file.
Regards
Dhaval
For future readers,
This is a bug in the OpenPRU repo's older C projects that was fixed in v2026.1.0.
On tag v2026.0.0, you can see that --disable_auto_rts was copied from the assembly projects into the C project settings that CCS imports:
https://github.com/TexasInstruments/open-pru/blob/v2026.00.00/examples/empty_c/firmware/am64x-evm/icss_g0_pru0_fw/ti-pru-cgt/example.projectspec
However, on tag v2026.1.0 I updated example.projectspec for all projects in the repo:
https://github.com/TexasInstruments/open-pru/blob/v2026.01.00/examples/empty_c/firmware/am64x-evm/icss_g0_pru0_fw/ti-pru-cgt/example.projectspec
If you see any other issues with importing projects into CCS, please let us know so we can take a look.
Regards,
Nick
I'm sorry but I unintentionally set this as "fixed my issue" but am only now just getting back around to trying, and neither Option A nor Option B worked.
Nothing changes with my build errors when I try Option A:
Building target: "ICSSG1_PRU0_AFDX.out"
Invoking: PRU Linker
"C:/ti/ti_cgt_pru_2.3.3/bin/clpru" -v4 -Ooff --define=SOC_AM64X --define=_DEBUG_=1 --define=PRU0 --define=SLICE1 -g --diag_warning=225 --diag_wrap=off --display_error_number --endian=little -z -m"abi=ti" --heap_size=0x100 --stack_size=0x200 --diag_suppress=10063-D --diag_wrap=off --display_error_number --warn_sections --xml_link_info="ICSSG1_PRU0_AFDX_linkInfo.xml" --entry_point=_c_int00_noinit_noargs --ram_model -o "ICSSG1_PRU0_AFDX.out" "./PRU_AFDX.obj" "./PRU_Clocks.obj" "./PRU_MDIO.obj" "./PRU_PCFG.obj" "./PRU_RGMII.obj" "./PRU_RegisterConfig.obj" "./PRU_Scheduler.obj" "./PRU_TaskManager.obj" "./PRU_Timer.obj" "./boot.obj" "./ethTxRx.obj" "./main.obj" "../linker.cmd"
<Linking>
undefined first referenced
symbol in file
--------- ----------------
__pruabi_mpyi ./PRU_Scheduler.obj
When I try option B, I get an additional build error that the linker can not find "libc.a":
Building target: "ICSSG1_PRU0_AFDX.out"
Invoking: PRU Linker
"C:/ti/ti_cgt_pru_2.3.3/bin/clpru" -v4 -Ooff --define=SOC_AM64X --define=_DEBUG_=1 --define=PRU0 --define=SLICE1 -g --diag_warning=225 --diag_wrap=off --display_error_number --endian=little -z -m"abi=ti" --heap_size=0x100 --stack_size=0x200 --disable_auto_rts --diag_suppress=10063-D --diag_wrap=off --display_error_number --warn_sections --xml_link_info="ICSSG1_PRU0_AFDX_linkInfo.xml" --entry_point=_c_int00_noinit_noargs --ram_model -o "ICSSG1_PRU0_AFDX.out" "./PRU_AFDX.obj" "./PRU_Clocks.obj" "./PRU_MDIO.obj" "./PRU_PCFG.obj" "./PRU_RGMII.obj" "./PRU_RegisterConfig.obj" "./PRU_Scheduler.obj" "./PRU_TaskManager.obj" "./PRU_Timer.obj" "./boot.obj" "./ethTxRx.obj" "./main.obj" "../linker.cmd" -llibc.a
<Linking>
error #10008-D: cannot find file "libc.a"
undefined first referenced
symbol in file
--------- ----------------
__pruabi_mpyi ./PRU_Scheduler.obj
To resolve, an additional step was required. Under Project Properties → Build → PRU Linker → File Search Path → Add <Dir> to library search path, I had to also add entries to:
C:\ti\ti_cgt_pru_2.3.3\include
C:\ti\ti_cgt_pru_2.3.3\lib
These file path additions, paired with manually adding "libc.a" resolved the error. Thanks.