[U-Boot] [PATCH] README.commands: Document what UNDEF_SYM does
Signed-off-by: Tom Rini trini@ti.com --- doc/README.commands | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/doc/README.commands b/doc/README.commands index 27815d2..21abfb6 100644 --- a/doc/README.commands +++ b/doc/README.commands @@ -22,6 +22,12 @@ 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_cmd_start.
+To ensure that the linker does not discard these symbols when linking +full U-Boot we use generate a list of all of the commands and force the +linker to first enter the symbol as undefined in the object so that +there is then a need for the symbol to be kept (UNDEF_SYM in the +Makefile). + 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:
On 09/19/2012 01:42 AM, Tom Rini wrote:
+To ensure that the linker does not discard these symbols when linking +full U-Boot we use generate a list of all of the commands and force the +linker to first enter the symbol as undefined in the object so that +there is then a need for the symbol to be kept (UNDEF_SYM in the +Makefile).
I have no idea what this is about, but my mind has difficulty parsing this sentence.
"To ensure that the linker does not discard these symbols when linking full U-Boot we use generate a list"
a generated list?
Regards, Jeroen
On Wed, Sep 19, 2012 at 11:09:56PM +0200, Jeroen Hofstee wrote:
On 09/19/2012 01:42 AM, Tom Rini wrote:
+To ensure that the linker does not discard these symbols when linking +full U-Boot we use generate a list of all of the commands and force the +linker to first enter the symbol as undefined in the object so that +there is then a need for the symbol to be kept (UNDEF_SYM in the +Makefile).
I have no idea what this is about, but my mind has difficulty parsing this sentence.
"To ensure that the linker does not discard these symbols when linking full U-Boot we use generate a list"
a generated list?
Bah, re-wrote the sentance a few times in my head as I was writing it. ... full U-Boot we geneate a list of all the commands we have built (based on the sections mentioned above) and use that to force the linker ...
participants (2)
-
Jeroen Hofstee -
Tom Rini