Modify the linux kernel but not working

[fengyuanyu1]

Hello, optee team, According to the guideline, I build the Linux with optee in QEMU successfully. I want to add some functions in the linux kernel using optee. But I find that my modification in optee project doesn't work. My pipeline is as following:

1. build optee project
2. modify the source code in <optee project>/linux
3. in <optee project>/build, make -f qemu_v8.mk linux
4. in <optee project>/build, make -f qemu_v8.mk run-only.

One of my modification is:

// <optee project>/linux/drivers/pci/probe.c
int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
            struct resource *res, unsigned int pos) {
        ...
        // line 318
        pci_info(dev, "Hack!!! reg 0x%x: %pR\n", pos, res);
        ...
}

And this modification can be complied successfully. But I cant find the HACK message in the boot log. I try to recompile the whole project, the Linux, change the compile flag. But it is useless.

[jforissier]

1. build optee project
2. modify the source code in /linux
3. in /build, make -f qemu_v8.mk linux
4. in /build, make -f qemu_v8.mk run-only.

That's mostly good except that the linux kernel is now post-processed to produce uImage (to be loaded by U-Boot). So the "make linux" target does not do enough. Please try the following patch:

diff --git a/qemu_v8.mk b/qemu_v8.mk
index 92702e0..324f8cf 100644
--- a/qemu_v8.mk
+++ b/qemu_v8.mk
@@ -394,6 +394,8 @@ $(KERNEL_UIMAGE): u-boot linux | $(BINARIES_PATH)
                -n "Linux kernel" \
                -d $(BINARIES_PATH)/linux.bin $(KERNEL_UIMAGE)

+uImage: $(KERNEL_UIMAGE)
+
 $(ROOTFS_UGZ): u-boot buildroot | $(BINARIES_PATH)
    ln -sf $(ROOT)/out-br/images/rootfs.cpio.gz $(BINARIES_PATH)
    $(MKIMAGE_PATH)/mkimage -A arm64 \

...and do the following sequence instead:

1. build optee project
2. modify the source code in /linux
3. in /build, make uImage
4. in /build, make run-only.

[jforissier]

https://github.com/OP-TEE/build/pull/677

[fengyuanyu1]

@jforissier Thanks for your quick reply. It works.