Rohini Kulkarni krohini1593 at
Tue Jun 23 18:37:27 UTC 2015

Hi all,

I am trying to understand boot up for ARM BSPs so as to be able to
implement SMP support for Pi 2.

Please correct me where I am wrong. (It is verbose. But I have tried to
make things as clear as I could)

[1] From start.S for ARM, all cores start together. They run the bsp_start
hook 0 and 1 and then go to boot_card() .
boot_card() calls rtems_data_sructure_initialize() which further does SMP
related initilazations.

[2] the bsp_start_hooks include cpu initialization for cache/mmu etc. This
is done for all cores before SMP initializations from boot_card(). For
Raspberry Pi 2, only primary core, which is core 0, will run after reset,
while other cores will wait for a jump address from where to execute.
I need to ensure the sequence remains consistent for Pi 2. So before
boot_card is called() , I need to get other cores to do the initialization
from start.S while core0 waits. Is there something else that can be done?

[3] Where do the other cores start waiting for an interrupt from primary
core. Where does the interprocessor interrupt come into picture.

Rohini Kulkarni
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