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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-01-20 09:04:43 (GMT) |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2017-01-28 19:04:38 (GMT) |
| commit | 65f321966177895ecdd2bdd21f3770f1746a9f8b (patch) | |
| tree | a6df4564f8bbac1adca4a96d4a175e0cc51e1cd4 | |
| parent | ab38bf6a3909bc773cbeec7b3997ba4686e6f93e (diff) | |
| download | u-boot-65f321966177895ecdd2bdd21f3770f1746a9f8b.tar.xz | |
arm64: spin-table: add more information in Kconfig help
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>
| -rw-r--r-- | arch/arm/cpu/armv8/Kconfig | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm/cpu/armv8/Kconfig b/arch/arm/cpu/armv8/Kconfig index 0b3d98e..0188b95 100644 --- a/arch/arm/cpu/armv8/Kconfig +++ b/arch/arm/cpu/armv8/Kconfig @@ -30,8 +30,10 @@ 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 |