Add a new CONFIG_X86_64 option which will eventually cause U-Boot to be built as a 64-bit application, with SPL doing the 16/32-bit init.
Signed-off-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com ---
Changes in v3: - Use tab instead of space in Kconfig help line
Changes in v2: None
arch/x86/Kconfig | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0884af22a79..5cd58d450b5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -5,6 +5,52 @@ config SYS_ARCH default "x86"
choice + prompt "Run U-Boot in 32/64-bit mode" + default X86_RUN_32BIT + help + U-Boot can be built as a 32-bit binary which runs in 32-bit mode + even on 64-bit machines. In this case SPL is not used, and U-Boot + runs directly from the reset vector (via 16-bit start-up). + + Alternatively it can be run as a 64-bit binary, thus requiring a + 64-bit machine. In this case SPL runs in 32-bit mode (via 16-bit + start-up) then jumps to U-Boot in 64-bit mode. + + For now, 32-bit mode is recommended, as 64-bit is still + experimental and is missing a lot of features. + +config X86_RUN_32BIT + bool "32-bit" + help + Build U-Boot as a 32-bit binary with no SPL. This is the currently + supported normal setup. U-Boot will stay in 32-bit mode even on + 64-bit machines. When booting a 64-bit kernel, U-Boot will switch + to 64-bit just before starting the kernel. Only the bottom 4GB of + memory can be accessed through normal means, although + arch_phys_memset() can be used for basic access to other memory. + +config X86_RUN_64BIT + bool "64-bit" + select X86_64 + select SUPPORT_SPL + select SPL + select SPL_SEPARATE_BSS + help + Build U-Boot as a 64-bit binary with a 32-bit SPL. This is + experimental and many features are missing. U-Boot SPL starts up, + runs through the 16-bit and 32-bit init, then switches to 64-bit + mode and jumps to U-Boot proper. + +endchoice + +config X86_64 + bool + +config SPL_X86_64 + bool + depends on SPL + +choice prompt "Mainboard vendor" default VENDOR_EMULATION