Hi all, I have a little question, how can I disable the hypervisor mode so EL2 will be just bridge to EL1 ns? (I mean without touching common ARM code only the platform-oriented code)
Thanks, Boaz.
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Hi,
I don't believe there is a way to "disable" NS EL2 if HW implements it. Although you can instruct TF-A to hand over (exception return) from BL31 to BL33 at NS EL1 (rather than NS EL2 by default). For Arm platforms you may override arm_get_spsr_for_bl33_entry: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/plat/arm/co...
This is called from two different sites (arm_bl2_handle_post_image_load, arm_bl31_early_platform_setup). I assume you may also tweak the bl2 load parameters like below (but that may be overridden by arm_get_spsr_for_bl33_entry) https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/plat/arm/co...
/* Fill BL33 related information */ { .image_id = BL33_IMAGE_ID, [...] .ep_info.pc = PLAT_ARM_NS_IMAGE_BASE, .ep_info.spsr = SPSR_64(MODE_EL1, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS),
Regards, Olivier.
________________________________________ From: TF-A tf-a-bounces@lists.trustedfirmware.org on behalf of IS20 Boaz Baron via TF-A tf-a@lists.trustedfirmware.org Sent: 14 September 2021 09:28 To: tf-a@lists.trustedfirmware.org Subject: [TF-A] Disable the EL2 hypervisor mode
Hi all, I have a little question, how can I disable the hypervisor mode so EL2 will be just bridge to EL1 ns? (I mean without touching common ARM code only the platform-oriented code)
Thanks, Boaz.
________________________________ The privileged confidential information contained in this email is intended for use only by the addressees as indicated by the original sender of this email. If you are not the addressee indicated in this email or are not responsible for delivery of the email to such a person, please kindly reply to the sender indicating this fact and delete all copies of it from your computer and network server immediately. Your cooperation is highly appreciated. It is advised that any unauthorized use of confidential information of Nuvoton is strictly prohibited; and any information in this email irrelevant to the official business of Nuvoton shall be deemed as neither given nor endorsed by Nuvoton.
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IS20 Boaz Baron -
Olivier Deprez