This feature seems to be sometimes misunderstood. The intention is:

[1] Bring the slaves into the U-Boot proper image, not SPL (unless you have a special reason to do otherwise).

[2] The operation must be done in a board (SoC) specific manner since how to wake the slaves from the Boot ROM is SoC specific.

[3] The slaves must enter U-Boot proper after U-Boot relocates itself because the "cpu-release-addr" property points to the relocated memory area.

[2] is already explained in the help. We can make [1] even clearer by mentioning "U-Boot proper" instead of "U-Boot". [3] is missing, so I am adding it to the list. Instead, "before the master CPU jumps to the kernel" is a matter of course, so removed.

Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com ---

Changes in v2: - Remove a trivial explanation, and rephrase

arch/arm/cpu/armv8/Kconfig | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/cpu/armv8/Kconfig b/arch/arm/cpu/armv8/Kconfig index 22dce88..fcc387c 100644 --- a/arch/arm/cpu/armv8/Kconfig +++ b/arch/arm/cpu/armv8/Kconfig @@ -12,8 +12,10 @@ config ARMV8_SPIN_TABLE To use this feature, you must do: - Specify enable-method = "spin-table" in each CPU node in the Device Tree you are using to boot the kernel - - Let secondary CPUs in U-Boot (in a board specific manner) - before the master CPU jumps to the kernel + - Bring secondary CPUs into U-Boot proper in a board specific + manner. This must be done *after* relocation. Otherwise, the + secondary CPUs will spin in unprotected memory area because the + master CPU protects the relocated spin code.

U-Boot automatically does: - Set "cpu-release-addr" property of each CPU node