Description
When using the 2025.10 version of the toolchain to debug firmware compiled with the zcmt extension, GDB exhibits parsing abnormalities when viewing the disassembly of zcmt instructions in the GDB window.
Current Behavior
The issue manifests differently on Windows and Linux systems:
Linux
When using the GDB window's disassemble function on functions containing zcmt instructions, GDB crashes with: Segmentation fault
Windows
GDB does not crash with a segmentation fault, but displays abnormal comments corresponding to zcmt instructions.
Root Cause
The root cause of this issue is that the zcmt functionality implementation was not adapted for GDB scenarios. When zcmt extension is enabled and users attempt to use GDB to view the disassembly display, this incompatibility leads to parsing errors or crashes.
Reproduction Steps
Compile firmware with zcmt extension enabled
Use GDB to debug the firmware
Attempt to view the disassembly of zcmt instructions in the GDB window
Observe the parsing error (segmentation fault on Linux, abnormal comments on Windows)
Workaround
Currently, it is recommended not to use the GDB window to view the disassembly of files compiled with zcmt extension to avoid this issue.
Fix Status
This issue is scheduled to be fixed in the next toolchain release.
Environment
Toolchain version: 2025.10
Architecture: RISC-V
Extension affected: zcmt sub-extension of zc extensions
Component affected: GDB (GNU Debugger)
Platforms affected: Linux (Segmentation fault), Windows (abnormal comments)
Additional Information
This bug affects all users who need to debug zcmt-enabled firmware using GDB's disassembly features. The temporary workaround is to avoid viewing zcmt instruction disassembly in GDB until the fix is released.
Description
When using the 2025.10 version of the toolchain to debug firmware compiled with the zcmt extension, GDB exhibits parsing abnormalities when viewing the disassembly of zcmt instructions in the GDB window.
Current Behavior
The issue manifests differently on Windows and Linux systems:
Linux
When using the GDB window's disassemble function on functions containing zcmt instructions, GDB crashes with: Segmentation fault
Windows
GDB does not crash with a segmentation fault, but displays abnormal comments corresponding to zcmt instructions.
Root Cause
The root cause of this issue is that the zcmt functionality implementation was not adapted for GDB scenarios. When zcmt extension is enabled and users attempt to use GDB to view the disassembly display, this incompatibility leads to parsing errors or crashes.
Reproduction Steps
Compile firmware with zcmt extension enabled
Use GDB to debug the firmware
Attempt to view the disassembly of zcmt instructions in the GDB window
Observe the parsing error (segmentation fault on Linux, abnormal comments on Windows)
Workaround
Currently, it is recommended not to use the GDB window to view the disassembly of files compiled with zcmt extension to avoid this issue.
Fix Status
This issue is scheduled to be fixed in the next toolchain release.
Environment
Toolchain version: 2025.10
Architecture: RISC-V
Extension affected: zcmt sub-extension of zc extensions
Component affected: GDB (GNU Debugger)
Platforms affected: Linux (Segmentation fault), Windows (abnormal comments)
Additional Information
This bug affects all users who need to debug zcmt-enabled firmware using GDB's disassembly features. The temporary workaround is to avoid viewing zcmt instruction disassembly in GDB until the fix is released.