- Also fixed an issue where NewLib ROM APIs, when called from TEE, were
using the syscall table located in the REE SRAM. This could be abused
as an attack vector to invoke illegal functions from the TEE.
To prevent this, the syscall table is now switched to the TEE-specific
copy during every M-U mode transition.
- Previously, only the U-mode interrupt threshold was raised in REE critical sections,
leaving M-mode at the lowest level.
- As a result, when a service call transitioned to M-mode, all interrupts were still
allowed to fire, including those that should have been masked.
- Ensure bound checks correctly handle all scenarios, including
when a requested operation's (SPI0/1) range fully contains the
TEE-protected region.
- Disable delegation of INTWDT timeout and Cache error interrupts as they reset
the device after the panic handler
- Fix incorrect setting in the edge interrupt acknowledgement API
- Avoid executing the service call dispatcher in the U-mode ecall,
rather execute `mret` to jump it
- Avoid `t1` register corruption when processing `ecall`
- Switch back to the bootloader stack from TEE stack after the
execution of the entire TEE initialization routine
- Remove `mret` for jumping to the service call dispatcher; instead, enable
interrupts and execute directly
- Fix potential corruption of the `t3` register when returning from a service
call
- Simplify the secure service dispatcher function
Laukik Hase