is sim/common documented anywhere?
Mike Frysinger
vapier@gentoo.org
Thu Aug 23 01:12:00 GMT 2012
On Wednesday 22 August 2012 19:41:42 DJ Delorie wrote:
> I've read through the comments and README. Mostly what's missing is
> some guide to help tell people where to begin, what parts to worry
> about, and WHY you'd use any given piece.
yes, some of the fundamental pieces explaining how it all comes together is
missing
> Example: how do I set up the chip's RAM/ROM regions?
you use sim_core_attach to attach memory regions. the mapmask allows you to
set different permissions on it. be aware that the sim currently has an issue
when used in conjunction with gdb -- the read/write bits not only lock out the
simulated code from accessing the region, but gdb too :(.
so you can't setup something like executable-only memory by specifying
access_exec as then when you try to use `x` or `dis` from gdb, you'd get back
an error -- the memory may not be read. similarly, if you were to try to use
`load` to load an executable with custom contents into that region you'd again
get denied -- gdb is not allowed to write to it.
i mentioned this a while ago seeking ideas, but didn't get any response.
> Do I want them to be user-configurable?
yes. the idea of the sim is two fold: provide simulation of the ISA with no
SoC related details (peripherals/memory regions/etc...), and then t optionally
provide support for common SoCs.
> If so, what's the best way to manage them?
check out sim-model.c. this lets you specify --model on the command line to
select different SoCs. this sets up CPU_MODEL (cpu) which you can then parse
in the early init phases of the sim (sim_open) to attach an appropriate set of
memory regions based on the model.
you can also use SIM_AC_OPTION_DEFAULT_MODEL() in your configure.ac to select
the default model for the sim if you want one.
if you have different ISAs to select between, you probably want to use --
architecture for that.
HTH
-mike
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: This is a digitally signed message part.
URL: <http://sourceware.org/pipermail/gdb/attachments/20120823/71b08151/attachment.sig>
More information about the Gdb
mailing list