kbuild: Bump the build system to 5.1

Our last sync with the kernel was 5.1. Even that was a partial one
as some patches from 4.x kernels were already missing making the
transition to a modern kbuild infeasible.

We are so out of sync now, that tracking the patches and backporting
them one by one makes little sense and it's going to take ages.

This is an attempt to sync up Makefile[.lib/.kbuild].
Unfortunately due to sheer amount of patches this is not easy to review,
but that's what we decided during a community call.

One of the biggest changes is get rid of partial linking entirely and
build .a archives isntead of .o.
We diaviate from the kernel on that. Instead of calling a custom script
to create the archive symbol table, we call ar with rcTP (isntead of
rcSTP) since we want a resulting archive that's sauble with the linker.

The only affected platforms are PPC ones. Unfortunately I don't have any
of them around to test, but the objdump of the resulting files --
arch/powerpc/lib/built-in.[oa] looks identical.

Signed-off-by: Ilias Apalodimas <[email protected]>

1 files changed, 4 insertions, 4 deletions

diff --git a/doc/api/linker_lists.rst b/doc/api/linker_lists.rst
index 3cd447f187d..9e6849d5e75 100644
--- a/doc/api/linker_lists.rst
+++ b/doc/api/linker_lists.rst
@@ -130,17 +130,17 @@ the compiler cannot update the alignment of the linker_list item.
 In the first case, an 8-byte 'fill' region is added::
 
    __u_boot_list_2_driver_2_testbus_drv
-               0x0000000000270018       0x80 test/built-in.o
+               0x0000000000270018       0x80 test/built-in.a
                0x0000000000270018                _u_boot_list_2_driver_2_testbus_drv
    __u_boot_list_2_driver_2_testfdt1_drv
-               0x0000000000270098       0x80 test/built-in.o
+               0x0000000000270098       0x80 test/built-in.a
                0x0000000000270098                _u_boot_list_2_driver_2_testfdt1_drv
    *fill*         0x0000000000270118        0x8
    __u_boot_list_2_driver_2_testfdt_drv
-               0x0000000000270120       0x80 test/built-in.o
+               0x0000000000270120       0x80 test/built-in.a
                0x0000000000270120                _u_boot_list_2_driver_2_testfdt_drv
    __u_boot_list_2_driver_2_testprobe_drv
-               0x00000000002701a0       0x80 test/built-in.o
+               0x00000000002701a0       0x80 test/built-in.a
                0x00000000002701a0                _u_boot_list_2_driver_2_testprobe_drv
 
 With this, the linker_list no-longer works since items after testfdt1_drv