From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Jos=E9_Miguel_Gon=E7alves?= Date: Mon, 17 Sep 2012 19:05:48 +0100 Subject: [U-Boot] [PATCH v2 09/11] S3C24XX: Add NAND Flash driver In-Reply-To: <5057643E.20806@ti.com> References: <1347643742-19966-1-git-send-email-jose.goncalves@inov.pt> <1347643742-19966-10-git-send-email-jose.goncalves@inov.pt> <201209142021.12033.marex@denx.de> <50537B54.2060903@inov.pt> <20120914190120.GL22028@bill-the-cat> <505598FF.7010108@inov.pt> <20120917165757.GA16252@bill-the-cat> <505758FA.2090805@inov.pt> <5057643E.20806@ti.com> Message-ID: <5057667C.6050604@inov.pt> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 17-09-2012 18:56, Tom Rini wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 09/17/12 10:08, Jos? Miguel Gon?alves 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 >>>>>>>> >>>>>>> [...] >>>>>>> >>>>>>>> +#include +#include +#include >>>>>>>> +#include +#include >>>>>>>> + +#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 ... >>>>>>> >>>>>>> 1) 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 >>>>>> 1) 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 :) The solution that I sorted out on the current SPL framework was to add this: #ifdef CONFIG_SPL_BUILD #define printf(arg...) do {} while (0) #ifdef CONFIG_SPL_SERIAL_SUPPORT #define puts(arg) serial_puts(arg) #endif #endif on a CPU specific header. Marek told me to not use macros, but to use inline functions instead, but has I told earlier on this thread, I am unable to do that. Suggestions for doing this in a better way are welcome...