On Tue, Aug 25, 2020 at 12:34:20PM +0000, Masahisa Kojima via Asa-dev wrote:

Hi Leif,

Thank you very much for your feedback.

On Wed, 12 Aug 2020 at 19:41, Leif Lindholm via Asa-dev asa-dev@op-lists.linaro.org wrote:

...

Hi all,

We've started looking at the TF-A qemu_sbsa port a bit, and found some things that were carried over from the mach-virt port for no good reason:

Looking at plat/qemu/qemu_sbsa/platform.mk:

• lib/cpus/aarch64/aem_generic.S is for fast models/foundation model.
  • although we may want to add a "generic armv8 cpu" to TF-A at some point, to reduce synchronization needs when bumping the cpu used by sbsa-ref in upstream QEMU.

For now, do we need to remove lib/cpus/aarch64/aem_generic.S and lib/cpus/aarch64/cortex_a57.S from sbsa-qemu?

...

• lib/cpus/aarch64/cortex_a53.S is not supported by sbsa-ref, nor does the A53 support enough physical address bits to be able to control this platform.

I'm not familiar with this item, is this a matter of QEMU side?

...

• drivers/io/io_semihosting.c, lib/semihosting/semihosting.c, and lib/semihosting/${ARCH}/semihosting_call.S are not actually used. But there *are* some other bits of qemu/common code which needs to be cinditionalized-out if these files aren't included.

We are not using semi-hosting, I will try to remove these files from the build target.

...

• plat/common/plat_psci_common.c
• all of the ${ARCH} stanzas should just be 'aarch64', this platform cannot be booted in aarch32.

I will fix this.

...

• plat/common/plat_psci_common.c isn't usefully hooked up to anything at the moment, but we can fix that when we get to actually implementing useful PSCI. That file may simply not belong in 'common'.

I'm still checking the contents of plat/common/plat_psci_common.c, most of the functions are optional.

Hi Masahisa, thanks for taking this on, just for your information I have been working on PSCI communicating with QEMU for shutdown/reset purposes so have currently this branch of stuff I had to break out of common qemu directory.

https://github.com/xXorAa/trusted-firmware-a/tree/secure-ec-wip

But I haven't done an in depth cleanup yet to make it more fine grained so if you have any comments or advice based on your work they would be greatfully received.

Thanks

Graeme