Hi Heinrich, On Tue, 17 Feb 2026 at 09:47, Heinrich Schuchardt <[email protected]> wrote: > > The UEFI specification requires at least 128 KiB stack space. Consider this > value as a prerequisite for CONFIG_EFI_LOADER. > > Mention the requirement in the CONFIG_STACK_SPACE description and decribe > that the UEFI sub-system uses CONFIG_STACK_SPACE when defining the memory > map. > > Signed-off-by: Heinrich Schuchardt <[email protected]> > --- > Kconfig | 8 +++++--- > lib/efi_loader/Kconfig | 2 ++ > 2 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/Kconfig b/Kconfig > index ce25ea24a60..99b3cd62526 100644 > --- a/Kconfig > +++ b/Kconfig > @@ -615,9 +615,11 @@ config STACK_SIZE > default 0x4000 if ARCH_STM32 > default 0x1000000 > help > - Define Max stack size that can be used by U-Boot. This value is used > - by the UEFI sub-system. On some boards initrd_high is calculated as > - base stack pointer minus this stack size. > + Define Max stack size that can be used by U-Boot. The UEFI > sub-system > + considers this value when setting up the memory map. The UEFI > + specification requires 128 KiB or more of available stack space. On > + some boards initrd_high is calculated as base stack pointer minus > this > + stack size. > > config SYS_MEM_TOP_HIDE > hex "Exclude some memory from U-Boot / OS information" > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig > index 13e44be1d06..450ffa61c0a 100644 > --- a/lib/efi_loader/Kconfig > +++ b/lib/efi_loader/Kconfig > @@ -15,6 +15,8 @@ config EFI_LOADER > # We need EFI_STUB_32BIT to be set on x86_32 with EFI_STUB > depends on !EFI_STUB || !X86 || X86_64 || EFI_STUB_32BIT > depends on !EFI_APP > + # The EFI specification requires 128 KiB or more of stack space > + depends on STACK_SIZE >= 0x20000
Won't this disable EFI for ARCH_STM32 devices? Those define the default stack size as 0x4000. Thanks /Ilias > default y if !ARM || SYS_CPU = armv7 || SYS_CPU = armv8 > select EFI > select CHARSET > -- > 2.51.0 >
