u-boot

History

Sebastien Carlier 6d8962e814 Switch from archive libraries to partial linking 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>		2010-11-17 21:02:18 +01:00
..
config.mk	Rename TEXT_BASE into CONFIG_SYS_TEXT_BASE	2010-10-18 22:07:10 +02:00
dbau1x00.c	mips: Move cpu/mips/* to arch/mips/cpu/*	2010-04-13 09:13:25 +02:00
flash.c	rename CFG_ macros to CONFIG_SYS	2008-10-18 21:54:03 +02:00
lowlevel_init.S	rename CFG_ macros to CONFIG_SYS	2008-10-18 21:54:03 +02:00
Makefile	Switch from archive libraries to partial linking	2010-11-17 21:02:18 +01:00
README	Rename TEXT_BASE into CONFIG_SYS_TEXT_BASE	2010-10-18 22:07:10 +02:00
u-boot.lds	MIPS: update the MIPS u-boot.lds	2010-09-04 11:52:17 +09:00

README

By Thomas.Lange@corelatus.se 2004-Oct-05
----------------------------------------
DbAu1xx0 are development boards from AMD containing
an Alchemy AU1xx0 series cpu with mips32 core.
Existing cpu:s are Au1000, Au1100, Au1500 and Au1550

Limitations & comments
----------------------
Support was originally big endian only.
I have not tested, but several u-boot users report working
configurations in little endian mode.

I named the board dbau1x00, to allow
support for all three development boards
( dbau1000, dbau1100 and dbau1500 ).
Now there is a new board called dbau1550 also, which
should be supported RSN.

I only have a dbau1000, so my testing is limited
to this board.

The board has two different flash banks, that can
be selected via dip switch. This makes it possible
to test new bootloaders without thrashing the YAMON
boot loader delivered with board.

NOTE! When you switch between the two boot flashes, the
base addresses will be swapped.
Have this in mind when you compile u-boot. CONFIG_SYS_TEXT_BASE has
to match the address where u-boot is located when you
actually launch.

Ethernet only supported for mac0.

PCMCIA only supported for slot 0, only 3.3V.

PCMCIA IDE tested with Sandisk Compact Flash and
IBM microdrive.

###################################
########     NOTE!!!!!!   #########
###################################
If you partition a disk on another system (e.g. laptop),
all bytes will be swapped on 16bit level when using
PCMCIA and running cpu in big endian mode!!!!

This is probably due to an error in Au1000 chip.

Solution:

a) Boot via network and partition disk directly from
dbau1x00. The endian will then be correct.

b) Partition disk on "laptop" and fill it with all files
you need. Then write a simple program that endian swaps
whole disk,

Example:
Original "laptop" byte order:
B0 B1 B2 B3 B4 B5 B6 B7 B8 B9...

Dbau1000 byte order will then be:
B1 B0 B3 B2 B5 B4 B7 B6 B9 B8...