Hi,

I'm trying to port L4Linux 3.14 to Linux Kernel 3.4. But when I complied the kernel, this error happened:

/home/shenyouren/workspace/kernel/kernel_exynos5250/arch/l4/kernel/main.c: In function 'cpu0_startup':

/home/shenyouren/workspace/kernel/kernel_exynos5250/arch/l4/kernel/main.c:2124:2: error: implicit declaration of function 'set_my_cpu_offset' [-Werror=implicit-function-declaration]

I checked main.c file:

#include <asm/unistd.h>

#include <asm/percpu.h>

#include <asm/generic/l4lib.h>

So I add one percpu.h file with definition of 'set_my_cpu_offset' in /home/shenyouren/workspace/kernel/kernel_exynos5250/arch/l4/include/asm/arch-arm/, however this error still happened.

Then I add the definition of this function to /home/shenyouren/workspace/kernel/kernel_exynos5250/include/linux/percpu.h, then the error message will not show.

Also, discard the change in $(src)/include/linux/percpu.h, then I change the main.c file to include  absolute path of percpu.h. 

#include <asm/unistd.h>

#include </home/shenyouren/workspace/kernel/kernel_exynos5250/arch/l4/include/asm/arch-arm/percpu.h>

#include <asm/generic/l4lib.h>

It passed the complied to.

So that is say, the #include <asm/percpu.h> is reference to src/include/linux/percpu.h. That really strange.

I do not change the Makefile in arch/l4, and I really confused about this error.

Now this problem occurs to me again, when complied the arch/l4/kernel/timer.c file, this error happened:

/home/shenyouren/workspace/kernel/kernel_exynos5250/arch/l4/kernel/timer.c:153:35: warning: 'struct clock_event_device' declared inside parameter list [enabled by default]

/home/shenyouren/workspace/kernel/kernel_exynos5250/arch/l4/kernel/timer.c:153:35: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]

but the definition of this to file should be defined in clockchips.h which is include in timer.c:

#include <linux/timex.h>

#include <linux/clockchips.h>

#include <linux/irq.h>

Thank you for your reading, I just want to know what's the rule of L4Linux header file linking, and solve this problem.

I'd be so appreciated if anyone can give me some help!