From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ua0-x22c.google.com ([2607:f8b0:400c:c08::22c]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bs94k-0004sP-4T for barebox@lists.infradead.org; Thu, 06 Oct 2016 13:51:10 +0000 Received: by mail-ua0-x22c.google.com with SMTP id p25so17991979uaa.1 for ; Thu, 06 Oct 2016 06:50:45 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <57f65594.d4491c0a.37103.324dSMTPIN_ADDED_BROKEN@mx.google.com> References: <57f65594.d4491c0a.37103.324dSMTPIN_ADDED_BROKEN@mx.google.com> From: Yegor Yefremov Date: Thu, 6 Oct 2016 15:50:24 +0200 Message-ID: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: am335x: memory configuration To: Jan Remmet Cc: barebox Hi Jan, On Thu, Oct 6, 2016 at 3:45 PM, Jan Remmet wrote: > On Thu, Oct 06, 2016 at 11:08:07AM +0200, Yegor Yefremov wrote: >> I've submitted a patch [1] to support our Baltos systems back in the >> May. There was an issue with dynamically detecting RAM size as the >> systems can have either 256MB or 512MB modules. >> >> So far u-boot was able to detect the RAM size dynamically. In order to >> do so it uses following code in arch/arm/cpu/armv7/am33xx/emif4.c: >> >> int dram_init(void) >> { >> >> #ifndef CONFIG_SKIP_LOWLEVEL_INIT >> sdram_init(); >> #endif >> >> /* dram_init must store complete ramsize in gd->ram_size */ >> gd->ram_size = get_ram_size( >> (void *)CONFIG_SYS_SDRAM_BASE, >> CONFIG_MAX_RAM_BANK_SIZE); >> return 0; >> } >> >> void dram_init_banksize(void) >> { >> gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE; >> gd->bd->bi_dram[0].size = gd->ram_size; >> } >> >> This peace of code will be excuted in u-boot.img (not in MLO). >> >> In Barebox we have get_ram_size(), that provides real RAM size and >> am335x_sdram_size(), that returns RAM controller settings. So far DDR >> controler will be configured for 512MB regardless of the module. Hence >> the return value from am335x_sdram_size() cannot be used for crating >> ram0 node. > On our am335x boards we use MLOs with individual RAM timings and EMIF config > values. So am335x_sdram_size works fine in barebox.bin. > Maybe get_ram_size works if the timing settings are equal? I've solved the problem the way Sascha proposed earlier (see the third version of my patch sent today). In MLO I setup memory controller to 512MB, then I check the real amount via get_ram_size() and if I have 256MB I just reinitialize the memory controller with values for 256Mb i.e. rows 14 instead of 15. With this done one can use am335x_sdram_size() in other parts of berebox. Thanks for the feedback. Yegor _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox