Files
zephyr/kernel/CMakeLists.txt
Tim Lin 2edece9d58 kernel: Add Kconfig option to disable LTO for kernel sources
Some SoCs require kernel code to be placed in RAM, which makes
link-time optimization (LTO) unsuitable for these files.
Disabling LTO allows the affected code to be linked as separate
objects and placed in specific memory regions.

Running kernel code from RAM can improve execution performance,
especially for timing-critical routines or context switch paths.

Signed-off-by: Tim Lin <tim2.lin@ite.corp-partner.google.com>
2026-01-21 17:04:50 +01:00

206 lines
5.5 KiB
CMake

# SPDX-License-Identifier: Apache-2.0
# kernel is a normal CMake library and not a zephyr_library because it
# should usually not be --whole-archive'd
zephyr_syscall_header(
${ZEPHYR_BASE}/include/zephyr/device.h
${ZEPHYR_BASE}/include/zephyr/kernel.h
${ZEPHYR_BASE}/include/zephyr/sys/kobject.h
${ZEPHYR_BASE}/include/zephyr/sys/time_units.h
)
# Helper macro to append files to the kernel_files list
macro(kernel_sources_ifdef feature_toggle)
if(${${feature_toggle}})
list(APPEND kernel_files ${ARGN})
endif()
endmacro()
macro(kernel_sources)
list(APPEND kernel_files ${ARGN})
endmacro()
if(NOT CONFIG_ERRNO_IN_TLS AND NOT CONFIG_LIBC_ERRNO)
zephyr_syscall_header(${ZEPHYR_BASE}/include/zephyr/sys/errno_private.h)
endif()
zephyr_syscall_header_ifdef(
CONFIG_ATOMIC_OPERATIONS_C
${ZEPHYR_BASE}/include/zephyr/sys/atomic_c.h
)
zephyr_syscall_header_ifdef(
CONFIG_MMU
${ZEPHYR_BASE}/include/zephyr/kernel/mm.h
${ZEPHYR_BASE}/include/zephyr/sys/mem_manage.h
)
zephyr_syscall_header_ifdef(
CONFIG_DEMAND_PAGING
${ZEPHYR_BASE}/include/zephyr/kernel/mm/demand_paging.h
)
# If a pre-built static library containing kernel code exists in
# this directory, libkernel.a, link it with the application code
# instead of building from source.
zephyr_library_get_current_dir_lib_name(${ZEPHYR_BASE} libkernel_stem)
set(libkernel ${CMAKE_CURRENT_SOURCE_DIR}/lib${libkernel_stem}${CMAKE_STATIC_LIBRARY_SUFFIX})
unset(libkernel_stem)
if(EXISTS ${libkernel})
add_library(kernel INTERFACE)
target_link_libraries(kernel INTERFACE ${libkernel})
else()
# FIXME: SHADOW_VARS: Remove this once we have enabled -Wshadow globally.
add_compile_options($<TARGET_PROPERTY:compiler,warning_shadow_variables>)
kernel_sources(
main_weak.c
banner.c
busy_wait.c
device.c
errno.c
fatal.c
init.c
kheap.c
mem_slab.c
float.c
version.c
)
kernel_sources_ifdef(CONFIG_SCHED_CPU_MASK
cpu_mask.c
)
kernel_sources_ifdef(CONFIG_MULTITHREADING
idle.c
mailbox.c
msg_q.c
mutex.c
queue.c
sem.c
stack.c
system_work_q.c
work.c
condvar.c
thread.c
sched.c
pipe.c
)
if(CONFIG_MULTITHREADING)
if(CONFIG_SCHED_SCALABLE OR CONFIG_WAITQ_SCALABLE)
kernel_sources(priority_queues.c)
endif()
kernel_sources_ifdef(CONFIG_SMP
smp.c
ipi.c)
else() # CONFIG_MULTITHREADING
kernel_sources(nothread.c)
endif() # CONFIG_MULTITHREADING
kernel_sources_ifdef(CONFIG_TIMESLICING timeslicing.c)
kernel_sources_ifdef(CONFIG_SPIN_VALIDATE spinlock_validate.c)
kernel_sources_ifdef(CONFIG_IRQ_OFFLOAD irq_offload.c)
kernel_sources_ifdef(CONFIG_BOOTARGS boot_args.c)
kernel_sources_ifdef(CONFIG_THREAD_MONITOR thread_monitor.c)
kernel_sources_ifdef(CONFIG_DEMAND_PAGING_STATS paging/statistics.c)
add_library(kernel ${kernel_files})
# Kernel files has the macro __ZEPHYR_SUPERVISOR__ set so that it
# optimizes the code when userspace is enabled.
set_target_properties(
kernel
PROPERTIES
COMPILE_DEFINITIONS
__ZEPHYR_SUPERVISOR__
)
target_sources_ifdef(CONFIG_REQUIRES_STACK_CANARIES kernel PRIVATE compiler_stack_protect.c)
target_sources_ifdef(CONFIG_SYS_CLOCK_EXISTS kernel PRIVATE timeout.c timer.c)
target_sources_ifdef(CONFIG_ATOMIC_OPERATIONS_C kernel PRIVATE atomic_c.c)
target_sources_ifdef(CONFIG_MMU kernel PRIVATE mmu.c)
target_sources_ifdef(CONFIG_POLL kernel PRIVATE poll.c)
target_sources_ifdef(CONFIG_EVENTS kernel PRIVATE events.c)
target_sources_ifdef(CONFIG_SCHED_THREAD_USAGE kernel PRIVATE usage.c)
target_sources_ifdef(CONFIG_OBJ_CORE kernel PRIVATE obj_core.c)
if(${CONFIG_KERNEL_MEM_POOL})
target_sources(kernel PRIVATE mempool.c)
if(CONFIG_HEAP_MEM_POOL_IGNORE_MIN)
set(final_heap_size ${CONFIG_HEAP_MEM_POOL_SIZE})
else()
# Import all custom HEAP_MEM_POOL size requirements
import_kconfig(CONFIG_HEAP_MEM_POOL_ADD_SIZE_ ${DOTCONFIG} add_size_keys)
# Calculate the sum of all "ADD_SIZE" requirements
set(add_size_sum 0)
foreach(add_size ${add_size_keys})
math(EXPR add_size_sum "${add_size_sum} + ${${add_size}}")
endforeach()
if(CONFIG_HEAP_MEM_POOL_SIZE LESS "${add_size_sum}")
# Only warn if default value 0 has been modified
if(NOT CONFIG_HEAP_MEM_POOL_SIZE EQUAL 0)
message(WARNING "
CONFIG_HEAP_MEM_POOL_SIZE is less than requested minimum:
${CONFIG_HEAP_MEM_POOL_SIZE} < ${add_size_sum}
Setting the system heap size to ${add_size_sum}")
endif()
set(final_heap_size ${add_size_sum})
else()
# CONFIG_HEAP_MEM_POOL_SIZE was greater than the sum of the requirements
set(final_heap_size ${CONFIG_HEAP_MEM_POOL_SIZE})
endif()
endif()
zephyr_compile_definitions(K_HEAP_MEM_POOL_SIZE=${final_heap_size})
endif()
# The last 2 files inside the target_sources_ifdef should be
# userspace_handler.c and userspace.c. If not the linker would complain.
# This order has to be maintained. Any new file should be placed
# above these 2 files.
target_sources_ifdef(
CONFIG_USERSPACE
kernel PRIVATE
futex.c
mem_domain.c
userspace_handler.c
userspace.c
)
if(${CONFIG_DYNAMIC_THREAD})
target_sources(kernel PRIVATE dynamic.c)
else()
target_sources(kernel PRIVATE dynamic_disabled.c)
endif()
target_include_directories(kernel PRIVATE
${ZEPHYR_BASE}/kernel/include
${ARCH_DIR}/${ARCH}/include
)
target_link_libraries(kernel zephyr_interface)
endif()
# Optionally build kernel sources without LTO
if(CONFIG_KERNEL_NO_LTO)
set_target_properties(kernel PROPERTIES LTO 0)
endif()
add_dependencies(kernel zephyr_generated_headers)
unset(libkernel)