Hi Stefano,
On 14/08/2012 17:19, Benoît Thébaudeau wrote:
The mx5 lowlevel_init.S contains code that detects the silicon revision at runtime, and that behaves differently if a silicon revision older than TO 3 is detected. This code is useless for recently designed boards that may not be fitted with older silicon revisions. Hence, this patch adds an option to optimize away this revision-specific code from lowlevel_init.S.
Signed-off-by: Benoît Thébaudeau benoit.thebaudeau@advansee.com Cc: Stefano Babic sbabic@denx.de
Hi Benoît,
Changes for v2:
- Make patch description more detailed.
.../arch/arm/cpu/armv7/mx5/lowlevel_init.S | 4 ++-- .../doc/README.imx5 | 7 ++++++- 2 files changed, 8 insertions(+), 3 deletions(-)
The ROM revision is currently detected at run time - because this does not fix an evident bug, your patch intends to reduce the footprint.
Then I chacked on a mx51evk, a board thet was shipped by Freescale with TO 2 (and maybe TO 1 ?), and there are surely samples with TO2 or TO3 in the world.
Without the poatch:
Configuring for mx51evk - Board: mx51evk, Options: IMX_CONFIG=board/freescale/mx51evk/imximage.cfg text data bss dec hex filename 258168 15872 268464 542504 84728 ./u-boot
With the patch:
Configuring for mx51evk - Board: mx51evk, Options: IMX_CONFIG=board/freescale/mx51evk/imximage.cfg text data bss dec hex filename 258140 15872 268492 542504 84728 ./u-boot
We win only 28 bytes - on the other side, we had a CONFIG_ that is not so clear how to be used, mainly if a board as the mx51evk was shipped with both versions.
To make things easier, this config should be used only for boards always shipped with the newer versions.
I think the advantages are negligible here.
Indeed. I needed that for a specific case where any single byte was worth saving. For upstream U-Boot, I let you decide if this is interesting enough or not.
Best regards, Benoît