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LS1043ARDB: Can I boot LS1043ARDB directly into AArch32 state from Power-On-Reset?

Question asked by Suresh G on Sep 1, 2016
Latest reply on Sep 1, 2016 by Pavel Chubakov

I expected that LS1043ARDB would have some switch settings to configure its execution state on Power-On-Reset so that it can be directly boot in either AArch64 or AArch32 state. But, it does not have any such switch settings.

Also, I checked "Reset configuration word (RCW)" in "QorIQ LS1043A Reference Manual". But, it also does not have any configuration to boot the CPU in AArch32 execution state.


But, Cortex-A53 core provides the option to configure the execution state during Power-On-Reset as explained below. Could you please teach me how LS1043A CPU treats this option? Is it hard coded to boot in AArch64? Or, is there any way to boot in AArch32? Please help me as I have to run a single Cortex-A7 compatible image in LS1043A.



----- ARM Cortex-A53 MPCore Processor Technical Reference Manual ------


4.3.76 Reset Management Register


Purpose    Controls the execution state that the processor boots into and allows request of a warm reset.


AA64a       Determines which execution state the processor boots into after a warm reset. The possible values are:
            0    AArch32 Execution state.
            1    AArch64 Execution state.


a. The cold reset value depends on the AA64nAA32 signal.



Thank you in advance.