On Tuesday 13 September 2016 07:30:38 Matthias Welwarsky wrote:
> That being said, can anyone share some code to switch a PE to Aarch32 mode?
> I'm on Rpi3, using a custom little program that does nothing but set up the
> GPIOs and then execute an endless loop. The program runs at EL2 in Aarch64
> state. This would certainly speed up work.

Another detail: Is there a reliable way to detect Aarch32 vs -64 state other 
than reading DSPSR (which clobbers X0). We need to first save X0/R0 or its 
value is lost, but all current code reads DSPSR to detect core state. Of 
course saving X0/R0 requires copying the register into DTR, which differs 
between the states.

BR,
Matthias

> 
> > David
> > 
> > ________________________________________
> > From: Matthias Welwarsky <matth...@welwarsky.de>
> > Sent: Monday, September 12, 2016 12:39 AM
> > To: Duane Ellis
> > Cc: David Ung; openocd-devel@lists.sourceforge.net
> > Subject: Re: [OpenOCD-devel] OpenOCD Aarch64 support
> > 
> > On Sunday 11 September 2016 21:47:09 Matthias Welwarsky wrote:
> > > On Saturday 10 September 2016 23:27:15 Duane Ellis wrote:
> > > > > Do you know if there's a method to read registers that is usable in
> > > > > AArch32
> > > > > and -64 execution states?
> > > > 
> > > > NO - the basic technique is the same Insert an opcode - and use the
> > > > DCC
> > > > to
> > > > transfer data, but the opcodes are totally different.
> > > 
> > > OK.
> > 
> > Just noticed; MRC/MCR in AArch32 mode are compatible with ARM32. A1 == T1
> > and A2 == T2 encoding. So they're not completely insane.
> > 
> > BR,
> > Matthias
> > 
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