zephyr: Link MicroPython with the Zephyr kernel library.

MaureenHelm · dpgeorge · commit 2b0e64beaf59 · 2024-06-18T16:19:07.000+10:00
Unlike most other Zephyr libraries, libkernel.a is not built as a
whole-archive.

This change also fixes a linker error observed on nucleo_wb55rg while
preparing an upgrade to Zephyr v3.5.0, caused by an undefined reference to
`z_impl_k_busy_wait`.

Signed-off-by: Maureen Helm &lt;maureen.helm@analog.com&gt;
diff --git a/ports/zephyr/CMakeLists.txt b/ports/zephyr/CMakeLists.txt
@@ -109,6 +109,7 @@ zephyr_library_compile_definitions(
 )
 
 zephyr_library_sources(${MICROPY_SOURCE_QSTR})
+zephyr_library_link_libraries(kernel)
 
 add_dependencies(${MICROPY_TARGET} zephyr_generated_headers)
 
diff --git a/ports/zephyr/src/zephyr_start.c b/ports/zephyr/src/zephyr_start.c
@@ -36,8 +36,4 @@ void main(void) {
     zephyr_getchar_init();
     #endif
     real_main();
-
-    // This is needed so the linker includes k_timer_init, z_impl_k_timer_start
-    // and z_impl_k_timer_stop, as used by libmicropython.a.
-    k_timer_start(NULL, K_MSEC(0), K_MSEC(0));
 }

Original file line number	Diff line number	Diff line change
`@@ -109,6 +109,7 @@ zephyr_library_compile_definitions(`
`109`	`109`	`)`
`110`	`110`
`111`	`111`	`zephyr_library_sources(${MICROPY_SOURCE_QSTR})`
	`112`	`+zephyr_library_link_libraries(kernel)`
`112`	`113`
`113`	`114`	`add_dependencies(${MICROPY_TARGET} zephyr_generated_headers)`
`114`	`115`
Original file line number	Diff line number	Diff line change
`@@ -36,8 +36,4 @@ void main(void) {`
`36`	`36`	`zephyr_getchar_init();`
`37`	`37`	`#endif`
`38`	`38`	`real_main();`
`39`		`-`
`40`		`- // This is needed so the linker includes k_timer_init, z_impl_k_timer_start`
`41`		`- // and z_impl_k_timer_stop, as used by libmicropython.a.`
`42`		`- k_timer_start(NULL, K_MSEC(0), K_MSEC(0));`
`43`	`39`	`}`