diff options
author | Tom Rini <trini@ti.com> | 2013-03-18 12:31:00 -0400 |
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committer | Tom Rini <trini@ti.com> | 2013-03-18 14:37:18 -0400 |
commit | 0ce033d2582129243aca10d3072a221386bbba44 (patch) | |
tree | 6e50a3f4eed22007549dc740d0fa647a6c8cec5b /doc/README.commands | |
parent | b5bec88434adb52413f1bc33fa63d7642cb8fd35 (diff) | |
parent | b27673ccbd3d5435319b5c09c3e7061f559f925d (diff) |
Merge branch 'master' of git://git.denx.de/u-boot-arm
Albert's rework of the linker scripts conflicted with Simon's making
everyone use __bss_end. We also had a minor conflict over
README.scrapyard being added to in mainline and enhanced in
u-boot-arm/master with proper formatting.
Conflicts:
arch/arm/cpu/ixp/u-boot.lds
arch/arm/cpu/u-boot.lds
arch/arm/lib/Makefile
board/actux1/u-boot.lds
board/actux2/u-boot.lds
board/actux3/u-boot.lds
board/dvlhost/u-boot.lds
board/freescale/mx31ads/u-boot.lds
doc/README.scrapyard
include/configs/tegra-common.h
Build tested for all of ARM and run-time tested on am335x_evm.
Signed-off-by: Tom Rini <trini@ti.com>
Diffstat (limited to 'doc/README.commands')
-rw-r--r-- | doc/README.commands | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/doc/README.commands b/doc/README.commands index 923418b1a4..9eb367104f 100644 --- a/doc/README.commands +++ b/doc/README.commands @@ -15,24 +15,22 @@ help: Long description. This is a string **** Behind the scene ****** -The structure created is named with a special prefix (__u_boot_list_cmd_) -and placed by the linker in a special section. +The structure created is named with a special prefix and placed by +the linker in a special section using the linker lists mechanism +(see include/linker_lists.h) This makes it possible for the final link to extract all commands compiled into any object code and construct a static array so the -command can be found in an array starting at _u_boot_list_cmd__start. +command array can be iterated over using the linker lists macros. -To ensure that the linker does not discard these symbols when linking -full U-Boot we generate a list of all the commands we have built (based -on the sections mentioned above) and use that to force the linker to -first enter the symbol as undefined in the output object so that there -is then a need for the symbol to be kept (this is the UNDEF_SYM logic in -the Makefile). +The linker lists feature ensures that the linker does not discard +these symbols when linking full U-Boot even though they are not +referenced in the source code as such. If a new board is defined do not forget to define the command section by writing in u-boot.lds ($(TOPDIR)/board/boardname/u-boot.lds) these 3 lines: .u_boot_list : { - #include "u-boot.lst"; + KEEP(*(SORT(.u_boot_list*))); } |