TMS570LS0914: Facing undefEntry issue with AUTOSAR SPI MCAL

Hi Usha,

Apologies for the delayed response!

I never came across this issue before.
However, we have one internal AI which can analyze old data e2e database and all the documents related to this controller. When i feed this issue i got below useful information and solutions. Please verify them and use it once.

The problem you're experiencing with the LR pointing to __TI_Decompress_None and jumping to undefEntry is related to BFI.W (Bit Field Insert) instruction incompatibility.

Root Cause

The BFI.W instruction is a Thumb-2 instruction that is NOT supported by the Cortex-R4F core in the TMS570LS0914. This instruction is only available in:

• Cortex-R5F and later cores
• Cortex-M3/M4 cores with Thumb-2 extensions

When the processor encounters the BFI.W instruction, it triggers an undefined instruction exception, causing execution to jump to undefEntry

Why This Happens

The issue typically occurs when:

1. Pre-compiled libraries (like F021 Flash API, TI_Fee libraries, or decompression routines) were compiled with optimization settings that generate Thumb-2 instructions including BFI.W

2. The __TI_Decompress_None function is part of the linker-generated initialization/decompression routines used during C/C++ auto-initialization at boot time

3. These routines may have been compiled for a different target (Cortex-R5F) or with incompatible compiler flags

Solutions

Solution 1: Recompile Libraries with Correct Compiler Flags

You need to ensure all libraries and code are compiled specifically for Cortex-R4F without Thumb-2 advanced instructions:

Compiler Settings in CCS:

• Go to: Project Properties -> Build -> ARM Compiler -> Advanced Options -> Target
• Set --code_state=32 (ARM mode) or ensure Thumb mode doesn't use advanced instructions
• Add to miscellaneous flags: --float_support=VFPv3D16
• Ensure optimization level is appropriate (try -O2 or -O3 instead of -O4)

For F021 Flash API Library: If you're using pre-compiled F021 Flash API libraries, you may need to:

1. Obtain the source code for F021 Flash API
2. Recompile it with the correct target settings for TMS570LS0914 (Cortex-R4F)
3. Link against your recompiled library

Solution 2: Check Linker Command File and Initialization

Ensure your linker command file properly handles initialization sections:

SECTIONS
{
    .text:decompress : {} > FLASH  /* Decompression routines */
    .cinit : {} > FLASH            /* C initialization table */
    .pinit : {} > FLASH            /* C++ initialization */
}

Make sure decompression routines are placed in executable memory and properly aligned

Solution 3: Disable Compression

If the issue is in the decompression routine, you can disable linker compression:

In your linker options, add:

--compress=off

This prevents the linker from compressing initialization data, avoiding the need for decompression routines

Solution 4: Verify Runtime Library

Ensure you're linking against the correct runtime support library for Cortex-R4F:

• Use rtsv7R4_T_le_v3D16_eabi.lib (for little-endian, VFPv3D16, EABI)
• NOT libraries compiled for Cortex-R5F

Debugging Steps

1. Check the disassembly at the address where LR points:

   • In CCS debugger, go to the address in LR register
   • Look for BFI.W or other Thumb-2 only instructions

2. Check Instruction Fault Status Register:

   • Read the Cortex-R4 IFSR register to confirm undefined instruction fault

3. Verify library compilation:

   • Check which libraries are being linked
   • Ensure they're compiled for Cortex-R4F, not R5F

Additional Recommendations

1. SPI Communication: Ensure your SPI1 configuration is correct and not causing memory corruption that could lead to executing invalid instructions

2. Stack Configuration: Verify adequate stack space is allocated, as stack overflow can cause similar symptoms

3. Memory Protection: Check MPU settings if enabled, as they could cause exceptions

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Thanks & Regards,
Jagadish.