[U-Boot] [PATCH v3 17/28] x86: Add a way to call 32-bit code from 64-bit mode

[Simon Glass]

On 4 August 2015 at 12:33, Simon Glass <sjg at chromium.org> wrote:
> The procedure to drop from 64-bit mode to 32-bit is a bit messy. Add a
> function to take care of it. It requires identity-mapped pages and that
> the calling code is running below 4GB.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
> ---
>
> Changes in v3: None
> Changes in v2:
> - Add a comment about the REX prefix
> - Drop the REX prefix in 32-bit mode
>
>  arch/x86/cpu/Makefile      |  6 +++++
>  arch/x86/cpu/call32.S      | 64 ++++++++++++++++++++++++++++++++++++++++++++++
>  arch/x86/include/asm/cpu.h |  9 +++++++
>  3 files changed, 79 insertions(+)
>  create mode 100644 arch/x86/cpu/call32.S

Applied to u-boot-x86.