At the moment we build the SPL and U-Boot proper for the 64-bit AArch64 instruction set. But since the cores provide an AArch32 compatibility mode and in fact the BootROM runs in 32-bit mode, it can be useful to have at least the SPL run in AArch32 as well. This has two advantages: - As AArch32 features the compact Thumb2 instruction encoding, we can get a much smaller image size, which is a relief for our SPL. - Staying in AArch32, with the MMU turned off, allows an easy return to the BootROM and its FEL mode. This enables FEL booting on those SoCs.
Introduce a Kconfig option which toggles between CONFIG_ARM64 and CONFIG_CPU_V7A, to allow easy switching between the two modes. This can be manually selected in menuconfig, but follow-up patches will introduce a separate defconfig for that purpose.
Signed-off-by: Andre Przywara andre.przywara@arm.com --- arch/arm/mach-sunxi/Kconfig | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig index 74e234cded..347d737fd0 100644 --- a/arch/arm/mach-sunxi/Kconfig +++ b/arch/arm/mach-sunxi/Kconfig @@ -146,6 +146,10 @@ config SUNXI_DRAM_MAX_SIZE default 0xC0000000 if MACH_SUN50I || MACH_SUN50I_H5 || MACH_SUN50I_H6 default 0x80000000
+config SUNXI_ARMV8_32BIT_BUILD + bool "Build 32-bit binaries for ARMv8 SoCs" + default n + choice prompt "Sunxi SoC Variant" optional @@ -275,7 +279,8 @@ config MACH_SUN9I
config MACH_SUN50I bool "sun50i (Allwinner A64)" - select ARM64 + select ARM64 if !SUNXI_ARMV8_32BIT_BUILD + select CPU_V7A if SUNXI_ARMV8_32BIT_BUILD select DM_I2C select PHY_SUN4I_USB select SUN6I_PRCM @@ -291,14 +296,16 @@ config MACH_SUN50I
config MACH_SUN50I_H5 bool "sun50i (Allwinner H5)" - select ARM64 + select ARM64 if !SUNXI_ARMV8_32BIT_BUILD + select CPU_V7A if SUNXI_ARMV8_32BIT_BUILD select MACH_SUNXI_H3_H5 select FIT select SPL_LOAD_FIT
config MACH_SUN50I_H6 bool "sun50i (Allwinner H6)" - select ARM64 + select ARM64 if !SUNXI_ARMV8_32BIT_BUILD + select CPU_V7A if SUNXI_ARMV8_32BIT_BUILD select SUPPORT_SPL select FIT select SPL_LOAD_FIT