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On 09/17/12 10:08, José Miguel Gonçalves wrote:
On 17-09-2012 17:57, Tom Rini wrote:
On Sun, Sep 16, 2012 at 10:16:47AM +0100, Jos? Miguel Gon?alves wrote:
On 09/14/2012 08:01 PM, Tom Rini wrote:
On Fri, Sep 14, 2012 at 07:45:40PM +0100, Jos? Miguel Gon?alves wrote:
On 14-09-2012 19:21, Marek Vasut wrote:
Dear Jos? Miguel Gon?alves,
> NAND Flash driver with HW ECC for the S3C24XX SoCs. > Currently it only supports SLC NAND chips. > > Signed-off-by: Jos? Miguel Gon?alves > jose.goncalves@inov.pt [...]
> +#include <common.h> +#include <nand.h> +#include > <asm/io.h> +#include <asm/arch/s3c24xx_cpu.h> +#include > <asm/errno.h> + +#define MAX_CHIPS 2 +static int > nand_cs[MAX_CHIPS] = { 0, 1 }; + +#ifdef > CONFIG_SPL_BUILD +#define printf(arg...) do {} while > (0) This doesn't seem quite right ...
- this should be in CPU directory 2) should be enabled
only if CONFIG_SPL_SERIAL_SUPPORT is not set 3) should be inline function, not a macro
- and 3) OK. Don't quite understand 2). I want to remove
the printfs in the SPL build, as it would blown up the internal SoC RAM space available. So why add a condition with CONFIG_SPL_SERIAL_SUPPORT?
You've got 8KB, based on the final patch in the series. At least in my SPL series that's still enough to get you printf/puts (I believe 4kb was the cutoff where that had to be dropped).
Barely:
$ size u-boot-spl text data bss dec hex filename 3337 8 588 3933 f5d u-boot-spl
$ size u-boot-spl-printf text data bss dec hex filename 7968 8 604 8580 2184 u-boot-spl-printf
The printf is not so important that justifies exhausting the IRAM space available and preventing any future SPL expansion...
There's two parts to this: - What else can you do in a single binary, in theory? Is there boot medium detection and you would want to have, for example, NAND and SD support in the same binary? I would say memory is meant for using, but this is a board maintainer decision and that's you :)
That's exactly what I've got in mind when I talked about a future expansion! Being able to boot also from an SD card. With only 8KB for .text and .data, I can not use printfs in the SPL for this platform (at least with the present printf support for SPL).
- We have a define today (CONFIG_SPL_LIBCOMMON_SUPPORT) that
toggles printf or no printf. If we really need to say yes to LIBCOMMON_SUPPORT and no to printf, we need finer grained config options and then a do-nothing printf is used for SPL. Doing the opt-out driver by driver just punts this problem down the road to the next developer and that's not very nice (and adding CONFIG_SPL_PRINTF_SUPPORT shouldn't be a big patch, modify a few Makefiles, update a bunch of config files, add common/spl/dummy_funcs.c and a __weak printf).
OK, so please take a stab at option two, on top of my SPL series, keeping in mind what Scott has said (which makes sense) because otherwise you'll be changing a lot of MMC files too to drop out printf :)
- -- Tom