From: Tim Newsome <tim@sifive.com>
To: David Blaikie <dblaikie@gmail.com>
Cc: Simon Marchi <simon.marchi@polymtl.ca>, gdb <gdb@sourceware.org>
Subject: Re: Remote query for structure layout
Date: Wed, 31 Mar 2021 07:06:19 -0700 [thread overview]
Message-ID: <CAGDihenjc+2P2we4i5+Zm8Fkzmj-FvHrpHN6HHzvQGZWgehERg@mail.gmail.com> (raw)
In-Reply-To: <CAENS6EuJwV4sxM6NwdffQ5bpPqkPrdk62qD_PNo0Jiy3pQqv=Q@mail.gmail.com>
On Tue, Mar 30, 2021 at 8:27 PM David Blaikie <dblaikie@gmail.com> wrote:
> (guess a side question: How's this different from other systems? I
> don't know how other/more common systems handle registers during
> signals)
Other systems have this same problem.
https://sourceforge.net/p/openocd/code/ci/master/tree/src/rtos/FreeRTOS.c
around line 440 has some heuristics.
For ARM, it assumes there are FPU registers on the stack "if (cpacr &
0x00F00000)".
For Cortex-M, it checks whether there are FPU registers on the stack by
reading something else off the stack.
The problem is worse on RISC-V because the architecture is intended to be
extensible. E.g. for pulpino additional registers are saved on the stack,
defined in
https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/95433d02848af0d274648ae4cdd846f6eff76dde/portable/GCC/RISC-V/chip_specific_extensions/Pulpino_Vega_RV32M1RM/freertos_risc_v_chip_specific_extensions.h#L76
Tim
next prev parent reply other threads:[~2021-03-31 14:06 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.6.1616932808.1485743.gdb@sourceware.org>
2021-03-30 20:35 ` Tim Newsome
2021-03-30 21:33 ` Simon Marchi
2021-03-30 21:41 ` David Blaikie
2021-03-30 21:49 ` Simon Marchi
2021-03-30 22:03 ` David Blaikie
2021-03-30 22:38 ` Simon Marchi
2021-03-30 22:44 ` David Blaikie
2021-03-31 0:16 ` Simon Marchi
2021-03-31 3:27 ` David Blaikie
2021-03-31 13:00 ` Simon Marchi
2021-04-02 22:05 ` David Blaikie
2021-04-03 19:39 ` Simon Marchi
2021-03-31 14:06 ` Tim Newsome [this message]
2021-03-28 11:06 Thomas Weißschuh
2021-03-29 16:05 ` Simon Marchi
2021-03-29 17:33 ` Thomas Weißschuh
2021-03-29 19:42 ` Simon Marchi
2021-03-29 20:02 ` Philippe Waroquiers
2021-03-29 20:10 ` Simon Marchi
2021-03-29 20:20 ` Philippe Waroquiers
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