• In aarch32 state, what is the mechanism to switch to aarch64 in software?
    Dear sirs, I'm reading arm v8a specification. I found that when arm is in aarch32 state, only a few exceptions can switch to aarch64 depending on the configuration in the registers. the exceptions are...
  • Using the Stack in AArch32 and AArch64
    When reading assembly-level code for any of the AArch32 or AArch64 instruction sets, you may have noticed that the stack pointer has various alignment and usage restrictions. These restrictions are part...
  • aarch64 kernel using aarch32 page tables
    Hi ! I'm trying to update my custom kernel, working with short or long descriptor in armv7a to a target supporting armv8. My current setup uses TTBR0 to point to the PL0 page table and TTBR1 to point...
  • Is it possible to move up from EL0 AARCH32 to EL1 AARCH64
    In baremetal boot code implementation https://developer.arm.com/documentation/dai0527/a , it is explained that depending on the SOC implementation, if the ARMv8 comes out on reset as EL3, AArch64 configuration...