| 1 |
24 |
jeremybenn |
How to use SIS with GDB
|
| 2 |
|
|
-----------------------
|
| 3 |
|
|
|
| 4 |
|
|
1. Building GDB with SIS
|
| 5 |
|
|
|
| 6 |
|
|
To build GDB with the SIS/ERC32 simulator, configure with option
|
| 7 |
|
|
'--target sparc-erc32-aout' and build as usual.
|
| 8 |
|
|
|
| 9 |
|
|
2. Attaching the simulator
|
| 10 |
|
|
|
| 11 |
|
|
To attach GDB to the simulator, use:
|
| 12 |
|
|
|
| 13 |
|
|
target sim [options] [files]
|
| 14 |
|
|
|
| 15 |
|
|
The following options are supported:
|
| 16 |
|
|
|
| 17 |
|
|
-nfp Disable FPU. FPops will cause an FPU disabled trap.
|
| 18 |
|
|
|
| 19 |
|
|
-freq Set the simulated "system clock" to MHz.
|
| 20 |
|
|
|
| 21 |
|
|
-v Verbose mode.
|
| 22 |
|
|
|
| 23 |
|
|
-nogdb Disable GDB breakpoint handling (see below)
|
| 24 |
|
|
|
| 25 |
|
|
The listed [files] are expected to be in aout format and will be
|
| 26 |
|
|
loaded in the simulator memory prior. This could be used to load
|
| 27 |
|
|
a boot block at address 0x0 if the application is linked to run
|
| 28 |
|
|
from RAM (0x2000000).
|
| 29 |
|
|
|
| 30 |
|
|
To start debugging a program type 'load ' and debug as
|
| 31 |
|
|
usual.
|
| 32 |
|
|
|
| 33 |
|
|
The native simulator commands can be reached using the GDB 'sim'
|
| 34 |
|
|
command:
|
| 35 |
|
|
|
| 36 |
|
|
sim
|
| 37 |
|
|
|
| 38 |
|
|
Direct simulator commands during a GDB session must be issued
|
| 39 |
|
|
with care not to disturb GDB's operation ...
|
| 40 |
|
|
|
| 41 |
|
|
For info on supported ERC32 functionality, see README.sis.
|
| 42 |
|
|
|
| 43 |
|
|
|
| 44 |
|
|
3. Loading aout files
|
| 45 |
|
|
|
| 46 |
|
|
The GDB load command loads an aout file into the simulator
|
| 47 |
|
|
memory with the data section starting directly after the text
|
| 48 |
|
|
section regardless of wich start address was specified for the data
|
| 49 |
|
|
at link time! This means that your applications either has to include
|
| 50 |
|
|
a routine that initialise the data segment at the proper address or
|
| 51 |
|
|
link with the data placed directly after the text section.
|
| 52 |
|
|
|
| 53 |
|
|
A copying routine is fairly simple, just copy all data between
|
| 54 |
|
|
_etext and _data to a memory loaction starting at _environ. This
|
| 55 |
|
|
should be done at the same time as the bss is cleared (in srt0.s).
|
| 56 |
|
|
|
| 57 |
|
|
|
| 58 |
|
|
4. GDB breakpoint handling
|
| 59 |
|
|
|
| 60 |
|
|
GDB inserts breakpoint in the form of the 'ta 1' instruction. The
|
| 61 |
|
|
GDB-integrated simulator will therefore recognize the breakpoint
|
| 62 |
|
|
instruction and return control to GDB. If the application uses
|
| 63 |
|
|
'ta 1', the breakpoint detection can be disabled with the -nogdb
|
| 64 |
|
|
switch. In this case however, GDB breakpoints will not work.
|
| 65 |
|
|
|
| 66 |
|
|
|
| 67 |
|
|
Report problems to Jiri Gaisler ESA/ESTEC (jgais@wd.estec.esa.nl)
|
