From: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> [ Upstream commit 76950f7162cad51d2200ebd22c620c14af38f718 ] To perform the reserve_crashkernel() operation kexec uses SECTION_SIZE to find a memblock in a range. SECTION_SIZE is not defined for nommu systems. Trying to compile kexec in these conditions results in a build error: linux/arch/arm/kernel/setup.c: In function ‘reserve_crashkernel’: linux/arch/arm/kernel/setup.c:1016:25: error: ‘SECTION_SIZE’ undeclared (first use in this function); did you mean ‘SECTIONS_WIDTH’? crash_size, SECTION_SIZE); ^~~~~~~~~~~~ SECTIONS_WIDTH linux/arch/arm/kernel/setup.c:1016:25: note: each undeclared identifier is reported only once for each function it appears in linux/scripts/Makefile.build:265: recipe for target 'arch/arm/kernel/setup.o' failed Make KEXEC depend on MMU to fix the compilation issue. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/arm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2ba69df49cf86..45f2a5930379a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -2000,7 +2000,7 @@ config XIP_PHYS_ADDR config KEXEC bool "Kexec system call (EXPERIMENTAL)" depends on (!SMP || PM_SLEEP_SMP) - depends on !CPU_V7M + depends on MMU select KEXEC_CORE help kexec is a system call that implements the ability to shutdown your -- 2.20.1