Datasheet

Differences
ARM DUI 0064D Copyright © 1999-2001 ARM Limited. All rights reserved. 2-15
.text
.type $a,function @ or $t for Thumb
$a:
nop
The mapping symbol is in effect for the rest of the image, or until another
mapping symbol is encountered.
This provides a workaround for the disassembly and stepping restrictions listed
above for images that contain only ARM code or only Thumb code. However, it
means that literal pools are not detected and are disassembled as code, instead of
being displayed as data.
• GCC does not generate call frame information. This means actions that rely on
knowing the stack frame layout do not work. Specifically:
— No stack backtrace is available. Only the current function is shown in the
stack backtrace.
— Step out does not work.
Local variables and parameters are available in the variable view, however you
must step over the function prologue code that sets up the stack frame before they
show the correct values.
Line number information is available, so the source view correctly displays the
current source line.
IRQ and FIQ debugger internal variables
The ARM debuggers now support debug targets that create their own variables. These
are named
$<proc_name>$<variable_name> , where:
<proc_name> Is the name of the processor, as shown in the Target panel of the Control
system view (for example,
ARM1020E ).
<variable_name>
Is the name of the variable, and can include:
irq (For example, $ARM1020E$irq .) A target can export this variable
to provide a means of asserting the interrupt request pin. To
trigger an interrupt manually, set the value to 1. To clear the
interrupt, set it to 0. The processor CPSR must not be
configured to disable interrupts.
fiq (For example, $ARM1020E$fiq .) A target can export this variable
to provide a means of asserting the fast interrupt request pin.
To trigger a fast interrupt manually, set the value to 1. To clear
the fast interrupt, set it to 0. The processor CPSR must not be
configured to disable fast interrupts.
Your debug target might create other variables (for example,
ARM1020E$other ). See the
target documentation for details.