User guide

GUI Reference
Debugger Tab (Run/Debug Dialog Box)
You open this tab by clicking the Debugger tab on the Run/Debug dialog box for Nios II
Hardware and Nios II Instruction Set Simulator (ISS) configurations.
The Debugger tab contains settings that affect the IDE behavior during debug sessions. Some
settings also apply to run sessions. Most settings on this tab are grouped by category.
Debugger—Allows you to specify the application to use for debugging. The only
choice is the Nios II Elf Debugger.
Download and Reset—These settings determine if the IDE downloads code to the
target and resets the target. These settings apply to both run and debug sessions.
o Download Program to RAM —Downloads the executable software file (.elf)
to RAM at the start of a debug session.
o Attach to existing program on target (no download)—Attaches the
debugger and console to a process that is already running in hardware.
o Reset target and execute from reset vector (no download)—Allows you
to reset the target, attach the debugger and console to the process already
executing in hardware, and pause the debug session at the reset vector.
Important: This option is explicitly for debugging boot code from
flash.
Breakpoints at Start-up—These settings determine where the debugger suspends at
the start of a debug session. If no checkboxes are on, the debug session executes
until it encounters a user-inserted breakpoint.
o Break at main()— Causes the debugger to break at main(). This is
equivalent to inserting a breakpoint at the first instruction of main().
o Break at alt_main() —Causes the debugger to break at alt_main(). This is
equivalent to inserting a breakpoint at the first instruction of alt_main(). Use
this setting when debugging freestanding Nios II C/C++ application projects.
o Break at program entry point – Causes the debugger to break at the
program’s entry point. This is equivalent to inserting a breakpoint at the
program’s entry point, typically _start().
Advanced—These settings provide access to features that are not standard in the
Nios II IDE debug flow.
o Use FS2 console window for trace and watchpoint support - Turning this
option on launches the FS2 console (provided by First Silicon Solutions, Inc.)
at the start of debug sessions. This option is available only on Windows and is
always disabled on Linux.
o Verbose console mode - Turning this option on causes the client side of the
GDB debugger to display commands and responses sent to and from the
target system in the Console view for the GDB client process.
o Use the Altera generated initialization script for faster debug
performance—Turning this option off allows you to specify a custom GDB
initialization script to run at the start of debug sessions. This setting has little
impact on Nios II instruction set simulator targets. If you turn this setting off,
you must also specify the GDB command file.
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