projects / thirdparty / binutils-gdb.git / blame
| Commit | Line | Data |
|---|---|---|
| f4d2ff34 RS |
1 | 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 <f> Set the simulated "system clock" to <f> 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 <program>' and debug as | |
| 31 | usual. | |
| 32 | ||
| 33 | The native simulator commands can be reached using the GDB 'sim' | |
| 34 | command: | |
| 35 | ||
| 36 | sim <sis_command> | |
| 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) |