From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 03 Jun 2025 00:19:13 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uMDUv-0036Vc-2Y for lore@lore.pengutronix.de; Tue, 03 Jun 2025 00:19:13 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1uMDUv-0001Wr-2R for lore@pengutronix.de; Tue, 03 Jun 2025 00:19:13 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=CFjl5kZbKv/BBEOgFSI2LZg2c4J1VXtinoLXjTZ+2cs=; b=pjrXjQ6vwRH9XS3adyDct/UHif 4YEXohfuAh/45Zcun0w+Z/QOQrdS56hO/M3aLMVMiuJazLJwuwedUdl+NfeeCUjN1jMQ/nFQ/frK9 Djk/03zg1ZE5LnrqKgbLuR8He2XJDQsTrJOCtGzQmYNeGHbii5i69Kc9KZws1WEgKGCKNbbgNgxfj HgxVpsqBMhX22DbwGo0LkGqsVkP+miv1Vl/rADNtvo1sOYe8NJCdXyakbSl6LUVRQF3LcFRrI6c2C Slrj6WznnN+NVfiDD/SHL95lQ/3WEC0EP8xMSjoTjQZDZGN6Hzvls5lPnPx/M8mtpzxPMMc72CbJP 0dZbH8Cw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uMDU8-00000009Blf-1HT2; Mon, 02 Jun 2025 22:18:24 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uMDSO-00000009BUo-3G7S for barebox@lists.infradead.org; Mon, 02 Jun 2025 22:16:38 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1uMDSL-0001LI-Ec; Tue, 03 Jun 2025 00:16:33 +0200 Received: from pty.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::c5]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uMDSL-001WWm-0r; Tue, 03 Jun 2025 00:16:33 +0200 Received: from mfe by pty.whiteo.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1uMDSL-006mTy-0R; Tue, 03 Jun 2025 00:16:33 +0200 Date: Tue, 3 Jun 2025 00:16:33 +0200 From: Marco Felsch To: Sascha Hauer Cc: BAREBOX Message-ID: <20250602221633.i7xvmam4jwb22vwz@pengutronix.de> References: <20250602-createnv-v1-0-c3239ff875d5@pengutronix.de> <20250602-createnv-v1-2-c3239ff875d5@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250602-createnv-v1-2-c3239ff875d5@pengutronix.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250602_151636_820408_AE33E0E1 X-CRM114-Status: GOOD ( 28.54 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.3 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 2/5] partitions: Start partitions at 8MiB offset X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) Hi Sascha, On 25-06-02, Sascha Hauer wrote: > There are many SoCs that store the bootloader on the raw eMMC/SD device > outside of partitions. Examples are all i.MX SoCs and Rockchip SoCs. > Until now the first partition starts at offset 1MiB and with this we > risk conflicting with the bootloader. > > It's cumbersome to sort out all SoCs that have this problem. With > nowadays eMMC/SD card sizes it doesn't really matter anymore, so change > the 1MiB offset to 8MiB which is still only a small fraction of the > card size, but leaves enough space for putting the bootloader into. > > Note the change in the GPT partition handling introduced with this > change. The layout previously was: > > LBA0: MBR > LBA1: GPT header > LBA2-33: GPT partition entries > > which now becomes: > > LBA0: MBR > LBA1: GPT header > LBA16352-16383: GPT partition entries > > This means the GPT partition entries moved from LBA2 to just below the > 8MiB boundary and LBA2-16351 are now free for the bootloader. This helps > with with older SoCs on which the bootloader overlaps with the normal > location of the GPT partition entries, like i.MX7 and earlier. I know that eMMC became quite large these days but always 'wasting' 8MiB on systems which utilize the eMMC-boot partitions is not very user friendly. I liked the approach which I posted which gives the user the ability to decide how much space is required if any. Regards, Marco > Signed-off-by: Sascha Hauer > --- > common/partitions.c | 9 +++++++++ > common/partitions/efi.c | 8 ++++++-- > include/partitions.h | 6 ++++++ > 3 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/common/partitions.c b/common/partitions.c > index 25d5f15721fc5980c927863b2745c23d7149da92..b3129ddd5f203c906908adb422e4b8a6dfac25b2 100644 > --- a/common/partitions.c > +++ b/common/partitions.c > @@ -186,6 +186,9 @@ int partition_find_free_space(struct partition_desc *pdesc, uint64_t sectors, ui > struct partition *p; > uint64_t min_sec = PARTITION_ALIGN_SECTORS; > > + if (min_sec < partition_first_usable_lba()) > + min_sec = partition_first_usable_lba(); > + > min_sec = ALIGN(min_sec, PARTITION_ALIGN_SECTORS); > > if (partition_is_free(pdesc, min_sec, sectors)) { > @@ -223,6 +226,12 @@ int partition_create(struct partition_desc *pdesc, const char *name, > return -EINVAL; > } > > + if (lba_start < partition_first_usable_lba()) { > + pr_err("partition starts before first usable lba: %llu < %llu\n", > + lba_start, partition_first_usable_lba()); > + return -EINVAL; > + } > + > list_for_each_entry(part, &pdesc->partitions, list) { > if (region_overlap_end(part->first_sec, > part->first_sec + part->size - 1, > diff --git a/common/partitions/efi.c b/common/partitions/efi.c > index 92868e4a77e5688d547ee3f2cac3ab9534a4ebdb..d237f734df50987b2d8ae41f83edc3e744fcf604 100644 > --- a/common/partitions/efi.c > +++ b/common/partitions/efi.c > @@ -585,7 +585,7 @@ static __maybe_unused struct partition_desc *efi_partition_create_table(struct b > gpt_header *gpt; > unsigned int num_partition_entries = 128; > unsigned int gpt_size = (sizeof(gpt_entry) * num_partition_entries) / SECTOR_SIZE; > - unsigned int first_usable_lba = gpt_size + 2; > + unsigned int first_usable_lba = partition_first_usable_lba(); > > partition_desc_init(&epd->pd, blk); > > @@ -719,7 +719,11 @@ static int efi_protective_mbr(struct block_device *blk) > return PTR_ERR(pdesc); > } > > - ret = partition_create(pdesc, "primary", "0xee", 1, last_lba(blk)); > + /* > + * For the protective MBR call directly into the mkpart hook. partition_create() > + * does not allow us to create a partition starting at LBA1 > + */ > + ret = pdesc->parser->mkpart(pdesc, "primary", "0xee", 1, last_lba(blk)); > if (ret) { > pr_err("Cannot create partition: %pe\n", ERR_PTR(ret)); > goto out; > diff --git a/include/partitions.h b/include/partitions.h > index dd3e631c5aa337d752312cd94be5e7dbb4f527a5..6d97af824845eaf8c73a39e42bd4e9ed88a8e367 100644 > --- a/include/partitions.h > +++ b/include/partitions.h > @@ -8,6 +8,7 @@ > #define __PARTITIONS_PARSER_H__ > > #include > +#include > #include > #include > #include > @@ -71,4 +72,9 @@ void partition_table_free(struct partition_desc *pdesc); > bool partition_is_free(struct partition_desc *pdesc, uint64_t start, uint64_t size); > int partition_find_free_space(struct partition_desc *pdesc, uint64_t sectors, uint64_t *start); > > +static inline uint64_t partition_first_usable_lba(void) > +{ > + return SZ_8M / SECTOR_SIZE; > +} > + > #endif /* __PARTITIONS_PARSER_H__ */ > > -- > 2.39.5 > > >