zephyr/kernel/CMakeLists.txt
Ederson de Souza 321e395a8f linker: Include libkernel.a in the whole-archive when llext is enabled
Differently from other libraries, which are included whole in the final
Zephyr ELF, libkernel.a itself isn't. Assuming this is intended to
enable optimisations (if it isn't, this patch will break things) - linker
can remove parts of the kernel that are not used by the application.

However, when considering Linkable Loadable Extensions (llext), this
optimisations can be counterproductive: for instance, syscalls that are
not used by the application won't be available for extensions. It won't
matter if someone "EXPORT_SYMBOL" for them, or even try to keep them
using LINKER_KEEP, they'll be gone.

To avoid that, this patches includes, when CONFIG_LLEXT=y, libkernel.a
inside the linker "whole-archive" block. This ends up making it consider
libkernel.a as a library whose all symbols should be kept. Note this
doesn't mean that all symbols will be there - things compiled out via
Kconfig will naturally still be out.

Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>
2024-03-26 19:31:56 -04:00

210 lines
5.1 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
${ZEPHYR_BASE}/include/zephyr/sys/time_units.h
)
if(NOT CONFIG_ERRNO_IN_TLS AND NOT CONFIG_LIBC_ERRNO)
zephyr_syscall_header(${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>)
list(APPEND kernel_files
main_weak.c
banner.c
busy_wait.c
device.c
errno.c
fatal.c
init.c
kheap.c
mem_slab.c
float.c
thread.c
version.c
priority_queues.c
sched.c
)
if(CONFIG_SCHED_CPU_MASK)
list(APPEND kernel_files
cpu_mask.c
)
endif()
if(CONFIG_MULTITHREADING)
list(APPEND kernel_files
idle.c
mailbox.c
msg_q.c
mutex.c
queue.c
sem.c
stack.c
system_work_q.c
work.c
condvar.c
)
if(CONFIG_SMP)
list(APPEND kernel_files
smp.c)
endif()
endif()
if(CONFIG_SPIN_VALIDATE)
list(APPEND kernel_files
spinlock_validate.c)
endif()
if(CONFIG_IRQ_OFFLOAD)
list(APPEND kernel_files
irq_offload.c
)
endif()
if(CONFIG_THREAD_MONITOR)
list(APPEND kernel_files
thread_monitor.c)
endif()
if(CONFIG_XIP)
list(APPEND kernel_files
xip.c)
endif()
if(CONFIG_DEMAND_PAGING_STATS)
list(APPEND kernel_files
paging/statistics.c)
endif()
add_library(kernel ${kernel_files})
# Kernel files has the macro __ZEPHYR_SUPERVISOR__ set so that it
# optimizes the code when userspace is enabled.
set_target_properties(
kernel
PROPERTIES
COMPILE_DEFINITIONS
__ZEPHYR_SUPERVISOR__
)
target_sources_ifdef(CONFIG_STACK_CANARIES kernel PRIVATE compiler_stack_protect.c)
target_sources_ifdef(CONFIG_SYS_CLOCK_EXISTS kernel PRIVATE timeout.c timer.c)
target_sources_ifdef(CONFIG_ATOMIC_OPERATIONS_C kernel PRIVATE atomic_c.c)
target_sources_ifdef(CONFIG_MMU kernel PRIVATE mmu.c)
target_sources_ifdef(CONFIG_POLL kernel PRIVATE poll.c)
target_sources_ifdef(CONFIG_EVENTS kernel PRIVATE events.c)
target_sources_ifdef(CONFIG_PIPES kernel PRIVATE pipes.c)
target_sources_ifdef(CONFIG_SCHED_THREAD_USAGE kernel PRIVATE usage.c)
target_sources_ifdef(CONFIG_OBJ_CORE kernel PRIVATE obj_core.c)
if(${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()
add_dependencies(kernel zephyr_generated_headers)
unset(libkernel)