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TrustZone

Former Member

Hey all,

does anyone know where to find a tutorial of how to implement TrustZone on the Zynq device?

I have found the TrustZone Spec and the API but I don't know how to use it.

I'm looking for a "Hello World" like a secure UART (or similar) that I can only use in secure world but not in normal world. (or a similar program).
It would be great if it also includes the changes at hardware site.

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  • 0

    Hey all,

    I was just wondering if no one is working with TrustZone! At least I figured out what's about the TZAPI but I'm still missing the TZ monitor.
    Therefore now the question: Does anyone of you knows how to implement the TrustZone Monitor to switch from secure to normal world?

    br
    schlauby

  • 0 in reply to Former Member

    Hey all,

    I forgott to write in this forum as well, after writing my solution in the xilinx forum.

    My problem was regarded to the TZ_OCM_RAM0 register. Before starting the secure code we should set the TZ_OCM_RAM0 regarding to our scattering file.
    With this register we can set blocks of the OCM to either secure or non-secure. If all blocks are set to secure (default) we cannot run the non-secure world.

    Each bit in the register represents the TrustZone status for a 4 KB page. (0: Secure, 1: Non-Secure)

    I hope this information will help some of you.

    br
    Schlauby

  • 0 in reply to Former Member

    Hi Schlauby,

    I was wondering how you found the address of the TZ_OCM_RAM0 register? Like Fanghuaqi, I am using the Zynq TRM as a reference. I'm seeing a lot of coprocessor 15 commands, but no direct register access.

    Could you maybe post some Xil_Out32 calls or some assembler that you used to set these registers?

    TIA.

  • 0 in reply to Former Member

    On page 686 of my book, Chapter 29 "On Chip Memory" part 3 "Register Overview", I do see TZ_OCM_RAM0 . But when I look for the actual address in Appendix B "Register Details" section 28 "System Level Control Registers", page 1493, I can't find it anywhere in the table, even though I see the other registers there.

  • 0 in reply to Former Member

    So I tried just setting every unknown TrustZone register in the SLCR to 0xFFFFFFFF, hoping to hit TZ_OCM_RAM0. And I'm still crashing whenever I try to switch to normal world.

    Code,

    #include <stdio.h>
    #include "TrustZone.h"
    #include "xil_io.h"

    void tz_init()
    {
    tint i;
        /* unlock */
    tfor (i = SCLR_TZ_BASE_OFFSET; i < TZ_DMA_NS_BASE_OFFSET; i += 4)
    ttXil_Out32(i, 0xFFFFFFFF);
        Xil_Out32(TZ_DMA_NS_BASE_OFFSET, 0x00000001);
        Xil_Out32(TZ_DMA_IRQ_NS_BASE_OFFSET, 0x0000FFFF);
        Xil_Out32(TZ_DMA_PERIPH_NS_BASE_OFFSET, 0x0000000F);
    tfor (i = TZ_DMA_PERIPH_NS_BASE_OFFSET; i < SCLR_TZ_BASE_OFFSET + 0x0100; i += 4)
    ttXil_Out32(i, 0xFFFFFFFF);
    }

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  • 0 in reply to Former Member

    So I tried just setting every unknown TrustZone register in the SLCR to 0xFFFFFFFF, hoping to hit TZ_OCM_RAM0. And I'm still crashing whenever I try to switch to normal world.

    Code,

    #include <stdio.h>
    #include "TrustZone.h"
    #include "xil_io.h"

    void tz_init()
    {
    tint i;
        /* unlock */
    tfor (i = SCLR_TZ_BASE_OFFSET; i < TZ_DMA_NS_BASE_OFFSET; i += 4)
    ttXil_Out32(i, 0xFFFFFFFF);
        Xil_Out32(TZ_DMA_NS_BASE_OFFSET, 0x00000001);
        Xil_Out32(TZ_DMA_IRQ_NS_BASE_OFFSET, 0x0000FFFF);
        Xil_Out32(TZ_DMA_PERIPH_NS_BASE_OFFSET, 0x0000000F);
    tfor (i = TZ_DMA_PERIPH_NS_BASE_OFFSET; i < SCLR_TZ_BASE_OFFSET + 0x0100; i += 4)
    ttXil_Out32(i, 0xFFFFFFFF);
    }

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