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What are you talking about? TrustZone is an ISA feature which lets you mark certain pages as "secure only". Compliant devices with SMMUs should not allow any ac
by sweetjuly 3y ago
What are you talking about? TrustZone is an ISA feature which lets you mark certain pages as "secure only". Compliant devices with SMMUs should not allow any access to these pages except when initiated by the secure world. It's not some big evil plan by Arm. It's up to vendors how they use it. Many just use it for key storage and verifying biometric data so that even a compromised kernel can't trivially steal the most sensitive data on a device.
If you start building your own hardware and/or buy devices with unlocked bootloaders, you can load whatever you want in EL3 to play with TZ. This isn't a problem with TZ.