diff options
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0884af2..5f9597b 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 @@ -89,6 +135,46 @@ config X86_RESET_VECTOR bool default n +# The following options control where the 16-bit and 32-bit init lies +# If SPL is enabled then it normally holds this init code, and U-Boot proper +# is normally a 64-bit build. +# +# The 16-bit init refers to the reset vector and the small amount of code to +# get the processor into 32-bit mode. It may be in SPL or in U-Boot proper, +# or missing altogether if U-Boot is started from EFI or coreboot. +# +# The 32-bit init refers to processor init, running binary blobs including +# FSP, setting up interrupts and anything else that needs to be done in +# 32-bit code. It is normally in the same place as 16-bit init if that is +# enabled (i.e. they are both in SPL, or both in U-Boot proper). +config X86_16BIT_INIT + bool + depends on X86_RESET_VECTOR + default y if X86_RESET_VECTOR && !SPL + help + This is enabled when 16-bit init is in U-Boot proper + +config SPL_X86_16BIT_INIT + bool + depends on X86_RESET_VECTOR + default y if X86_RESET_VECTOR && SPL + help + This is enabled when 16-bit init is in SPL + +config X86_32BIT_INIT + bool + depends on X86_RESET_VECTOR + default y if X86_RESET_VECTOR && !SPL + help + This is enabled when 32-bit init is in U-Boot proper + +config SPL_X86_32BIT_INIT + bool + depends on X86_RESET_VECTOR + default y if X86_RESET_VECTOR && SPL + help + This is enabled when 32-bit init is in SPL + config RESET_SEG_START hex depends on X86_RESET_VECTOR @@ -109,6 +195,14 @@ config SYS_X86_START16 depends on X86_RESET_VECTOR default 0xfffff800 +config X86_LOAD_FROM_32_BIT + bool "Boot from a 32-bit program" + help + Define this to boot U-Boot from a 32-bit program which sets + the GDT differently. This can be used to boot directly from + any stage of coreboot, for example, bypassing the normal + payload-loading feature. + config BOARD_ROMSIZE_KB_512 bool config BOARD_ROMSIZE_KB_1024 |