On 09/17/2012 11:57:57 AM, 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
- should be enabled only if CONFIG_SPL_SERIAL_SUPPORT is not set
- 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 :)
- 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).
Weak symbols are not OK for configuring printf out of the SPL, as you'll still have all the format strings and caller code in the binary. It should be a macro (or an inline function that replaces the standard printf declaration), but it should be in a system header (not the CPU directory -- not sure what Marek meant there) and be based on an appropriate CONFIG symbol.
-Scott