68 lines
2 KiB
Text
68 lines
2 KiB
Text
|
How to use SIS with GDB
|
||
|
|
-----------------------
|
||
|
|
|
||
|
|
1. Building GDB with SIS
|
||
|
|
|
||
|
|
To build GDB with the SIS/ERC32 simulator, configure with option
|
||
|
|
'--target sparc-erc32-aout' and build as usual.
|
||
|
|
|
||
|
|
2. Attaching the simulator
|
||
|
|
|
||
|
|
To attach GDB to the simulator, use:
|
||
|
|
|
||
|
|
target sim [options] [files]
|
||
|
|
|
||
|
|
The following options are supported:
|
||
|
|
|
||
|
|
-nfp Disable FPU. FPops will cause an FPU disabled trap.
|
||
|
|
|
||
|
|
-freq <f> Set the simulated "system clock" to <f> MHz.
|
||
|
|
|
||
|
|
-v Verbose mode.
|
||
|
|
|
||
|
|
-nogdb Disable GDB breakpoint handling (see below)
|
||
|
|
|
||
|
|
The listed [files] are expected to be in aout format and will be
|
||
|
|
loaded in the simulator memory prior. This could be used to load
|
||
|
|
a boot block at address 0x0 if the application is linked to run
|
||
|
|
from RAM (0x2000000).
|
||
|
|
|
||
|
|
To start debugging a program type 'load <program>' and debug as
|
||
|
|
usual.
|
||
|
|
|
||
|
|
The native simulator commands can be reached using the GDB 'sim'
|
||
|
|
command:
|
||
|
|
|
||
|
|
sim <sis_command>
|
||
|
|
|
||
|
|
Direct simulator commands during a GDB session must be issued
|
||
|
|
with care not to disturb GDB's operation ...
|
||
|
|
|
||
|
|
For info on supported ERC32 functionality, see README.sis.
|
||
|
|
|
||
|
|
|
||
|
|
3. Loading aout files
|
||
|
|
|
||
|
|
The GDB load command loads an aout file into the simulator
|
||
|
|
memory with the data section starting directly after the text
|
||
|
|
section regardless of wich start address was specified for the data
|
||
|
|
at link time! This means that your applications either has to include
|
||
|
|
a routine that initialise the data segment at the proper address or
|
||
|
|
link with the data placed directly after the text section.
|
||
|
|
|
||
|
|
A copying routine is fairly simple, just copy all data between
|
||
|
|
_etext and _data to a memory loaction starting at _environ. This
|
||
|
|
should be done at the same time as the bss is cleared (in srt0.s).
|
||
|
|
|
||
|
|
|
||
|
|
4. GDB breakpoint handling
|
||
|
|
|
||
|
|
GDB inserts breakpoint in the form of the 'ta 1' instruction. The
|
||
|
|
GDB-integrated simulator will therefore recognize the breakpoint
|
||
|
|
instruction and return control to GDB. If the application uses
|
||
|
|
'ta 1', the breakpoint detection can be disabled with the -nogdb
|
||
|
|
switch. In this case however, GDB breakpoints will not work.
|
||
|
|
|
||
|
|
|
||
|
|
Report problems to Jiri Gaisler ESA/ESTEC (jgais@wd.estec.esa.nl)
|