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>
Modifications are based on the linux kernel approach and
support two use cases:
1) Add O= to the make command line
'make O=/tmp/build all'
2) Set environement variable BUILD_DIR to point to the desired location
'export BUILD_DIR=/tmp/build'
'make'
The second approach can also be used with a MAKEALL script
'export BUILD_DIR=/tmp/build'
'./MAKEALL'
Command line 'O=' setting overrides BUILD_DIR environent variable.
When none of the above methods is used the local build is performed and
the object files are placed in the source directory.
- remove trailing white space, trailing empty lines, C++ comments, etc.
- split cmd_boot.c (separate cmd_bdinfo.c and cmd_load.c)
* Patches by Kenneth Johansson, 25 Jun 2003:
- major rework of command structure
(work done mostly by Michal Cendrowski and Joakim Kristiansen)
- Added support for custom keyboards, initialized by defining a
board-specific drv_keyboard_init as well as defining CONFIG_KEYBOARD .
- Added support for the RBC823 board.
- cpu/mpc8xx/lcd.c now automatically calculates the
Horizontal Pixel Count field.
* Fix alignment problem in BOOTP (dhcp_leasetime option)
[pointed out by Nicolas Lacressonnière, 2 Jun 2003]
* Patch by Mark Rakes, 14 May 2003:
add support for Intel e1000 gig cards.
* Patch by Nye Liu, 3 Jun 2003:
fix critical typo in MAMR definition (include/mpc8xx.h)
* Fix requirement to align U-Boot image on 16 kB boundaries on PPC.
* Patch by Klaus Heydeck, 2 Jun 2003
Minor changes for KUP4K configuration
