Re: [PATCH] ARM: rockchip: rk3066: set soc_remap before starting secondary cores

["Heiko Stübner" <heiko@sntech.de>]

Hi,

Am Freitag, 30. Oktober 2026, 08:36:47 Mitteleuropäische Normalzeit schrieb Yalçın Can:
> A Cortex-A9 core on the rk3066 starts at address 0 when it is powered up.
> The SMP code copies a trampoline to the start of the internal sram and
> relies on GRF_SOC_CON0 soc_remap (bit 12) mapping the sram at address 0.
> The vendor loader sets that bit before starting the kernel, but a boot
> loader started directly by the bootrom leaves it cleared. The core then
> runs the bootrom instead, which parks it and also writes into the start of
> the sram, so the trampoline's target word is overwritten as well, and the
> boot logs "CPU1: failed to come online".
> 
> Set soc_remap after the secondary cores have been powered down and before
> the trampoline is copied. The rk3188 shares these smp operations; its grf
> has a different compatible and is left alone.
> 
> Tested on an RK3066a board (MK808B) with U-Boot started from the NAND ID
> blocks by the bootrom: before, CPU1 never came online (GRF_SOC_CON0 bit 12
> clear, sram+4 read 0x00000001 instead of the physical address of
> secondary_startup); with this patch both cores come up at boot, three
> offline/online cycles of cpu1 work, and the board restarts normally after
> a reboot and after a forced panic. Booting through the vendor loader, which
> already sets the bit, is unchanged. Not tested on rk3188.
> 
> Fixes: a7a2b3118b41 ("ARM: rockchip: add smp bringup code")
> Assisted-by: Claude:claude-opus-5-5
> Signed-off-by: Yalçın Can <ylcncn@gmail.com>

there is another patch from Johan pending [0], which I plan to apply after
the merge-window, that moves all of the A9 cores over to booting via
the SoCs bootrom and gets rid of the whole trampoline code.


Heiko


[0] https://lore.kernel.org/linux-rockchip/20261017-cpu-v3-1-25d8f4b06362@gmail.com/