Xilinx Zynq 7000 Start of CPU1

Xilinx Zynq 7000 Start of CPU1

[Sebastian Huber]

Hello,

I recently added the support for CPU1 to the xilinx-zynq-a9 machine (hw/arm/xilinx_zynq.c). However, the reset behaviour doesn't match exactly with the hardware. After a system reset (SRST), the CPU1 should execute a wfe instruction and then load the start address from 0xfffffff0:

https://docs.amd.com/r/en-US/ug585-zynq-7000-SoC-TRM/Starting-Code-on-CPU-1

It would be great if someone has a hint for me how I can add this startup code for CPU1 at address region 0xFFFFFE00 to 0xFFFFFFF0.

Kind regards, Sebastian

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Herr Sebastian HUBER
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Re: Xilinx Zynq 7000 Start of CPU1

[Sebastian Huber]

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----- Am 18. Sep 2024 um 11:13 schrieb Sebastian Huber sebastian.huber@embedded-brains.de:

> Hello,
> 
> I recently added the support for CPU1 to the xilinx-zynq-a9 machine
> (hw/arm/xilinx_zynq.c). However, the reset behaviour doesn't match exactly with
> the hardware. After a system reset (SRST), the CPU1 should execute a wfe
> instruction and then load the start address from 0xfffffff0:
> 
> https://docs.amd.com/r/en-US/ug585-zynq-7000-SoC-TRM/Starting-Code-on-CPU-1
> 
> It would be great if someone has a hint for me how I can add this startup code
> for CPU1 at address region 0xFFFFFE00 to 0xFFFFFFF0.

I got it working with some hacks in arm_load_kernel() and do_cpu_reset(). In arm_load_kernel() had to remove the:

        /*
         * No secondary boot stub; don't use the reset hook that would
         * have set the CPU up to call it
         */
        info->write_secondary_boot = NULL;
        info->secondary_cpu_reset_hook = NULL;

This change probably breaks a lot of things. I am not sure how to address this issue.

-- 
embedded brains GmbH & Co. KG
Herr Sebastian HUBER
Dornierstr. 4
82178 Puchheim
Germany
email: sebastian.huber@embedded-brains.de
phone: +49-89-18 94 741 - 16
fax:   +49-89-18 94 741 - 08

Registergericht: Amtsgericht München
Registernummer: HRB 157899
Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler
Unsere Datenschutzerklärung finden Sie hier:
https://embedded-brains.de/datenschutzerklaerung/

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