On 26.02.19 00:32, Andre Przywara wrote: > Hi Alex, > > On 2/22/19 2:13 AM, Alexander Graf wrote: >> >> >> On 21.02.19 02:30, Andre Przywara wrote: >>> 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.przyw...@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 >> >> Can't you make this "imply ARM64" instead and then just set >> ARM64=n;CPU_V7A=y in the defconfig? > > Ha, that indeed sounds tempting, and actually I tried this before, but > it doesn't work. The kernel doc says that an "imply" setting can be > overwritten by a direct dependency or a visible prompt. ARM64 is not > visible (empty bool), so I figured that introducing this simple symbol > is the smallest pain to tackle this issue.
If you say you already did try imply, then I'm all happy :). Alex _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
