Before this commit, weak symbols were not overridden by non-weak symbols
found in archive libraries when linking with recent versions of
binutils. As stated in the System V ABI, "the link editor does not
extract archive members to resolve undefined weak symbols".
This commit changes all Makefiles to use partial linking (ld -r) instead
of creating library archives, which forces all symbols to participate in
linking, allowing non-weak symbols to override weak symbols as intended.
This approach is also used by Linux, from which the gmake function
cmd_link_o_target (defined in config.mk and used in all Makefiles) is
inspired.
The name of each former library archive is preserved except for
extensions which change from ".a" to ".o". This commit updates
references accordingly where needed, in particular in some linker
scripts.
This commit reveals board configurations that exclude some features but
include source files that depend these disabled features in the build,
resulting in undefined symbols. Known such cases include:
- disabling CMD_NET but not CMD_NFS;
- enabling CONFIG_OF_LIBFDT but not CONFIG_QE.
Signed-off-by: Sebastien Carlier <sebastien.carlier@gmail.com>
Reference:
http://plugcomputer.org/http://openplug.org/plugwiki/index.php/Das_U-boot_plug_support
This patch is tested for-
1. Boot from DRAM/NAND flash
2. File transfer using tftp
3. NAND flash read/write/erase
4. Linux kernel and RFS Boot from NAND
5. Enabled USB PHY init for kernel need
6. Boot from USB supported
Note: to boot Kirkwood kernel with USB support,
you should add "usb start" in the boot sequence
Signed-off-by: Prafulla Wadaskar <prafulla@marvell.com>
