From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 04FF919D89E for ; Thu, 25 Jun 2026 22:15:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782425752; cv=none; b=EVS4mCaf/31P8O5Vizib/daifSWhM+EbF4ONeLrpmVV782y/t9JzIVH+B5MbAevKo3VsBA8ur6xgO/XN77CKPB+oDfWGuK+wZvjr1v9FdaUqxYWAuIOnxXKkhPjLh4b6iqg60lFP96ye1tH6SLbAJoehwUAXyyULVwYmMwhKLJk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782425752; c=relaxed/simple; bh=gDxW/SjKUUq+rjJG9W40OLKuF1SD7j9+bM1j7XQBoig=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KZmeJWPA/bJ6xW+AIRPv1UWMBIUQJD88NPoApec9ogOkAz82Si9o17IzHiX4rdGzkQm+gJKBvUCx6wri1yOgPaN4EMdT14lr2/k/g08YP2GOYwAPw7hdaiCFWcxIj3e/QfWKS21yDkGsJ9erIuGRL5ivoTgaxacQqCvz4yhKvBA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25AFF1F000E9; Thu, 25 Jun 2026 22:15:47 +0000 (UTC) Message-ID: <5dd8cf26-533f-4a32-8885-3eaad7c57ed6@linux-m68k.org> Date: Fri, 26 Jun 2026 08:15:42 +1000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] mtd: maps: remove uclinux map driver To: Arnd Bergmann , Arnd Bergmann , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra Cc: Randy Dunlap , Andy Shevchenko , linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-m68k , Pengpeng Hou References: <20260526103227.3152003-1-arnd@kernel.org> <20260526103227.3152003-2-arnd@kernel.org> Content-Language: en-US From: Greg Ungerer In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Arnd, On 26/6/26 00:10, Arnd Bergmann wrote: > On Thu, Jun 25, 2026, at 14:07, Greg Ungerer wrote: >> On 26/5/26 20:32, Arnd Bergmann wrote: >> >> It is used on some ColdFire platforms, and was working all the way up >> to being removed in the current merge window. >> >> The ColdFire platform startup code (arch/m68k/coldfire/head.S) has a >> somewhat unusual setup that can copy an attached filesystem blob to >> _bss_stop, and this is one of the places the uclinux.c map driver can >> use as the filesystem memory address. From uclinux.c >> >> static int __init uclinux_mtd_init(void) >> { >> struct mtd_info *mtd; >> struct map_info *mapp; >> >> mapp = &uclinux_ram_map; >> >> if (physaddr == -1) >> mapp->phys = (resource_size_t)__bss_stop; >> else >> mapp->phys = physaddr; >> >> No out of tree code is required. Most of the ColdFire defconfigs have >> CONFIG_MTD_UCLINUX enabled, since it is commonly used. > > I see, this is surprising from reading the source and > git history, but I can see exactly how it got there. The early, and probably more interesting history, predates git. It has always "just worked" on ColdFire platforms, so it really hasn't needed alot of change over the years for this use case. > So this is not actually a device but rather a replacement > for CONFIG_BLK_DEV_INITRD that does can work with CONFIG_BLOCK=y, > right? Yes, that is true. Typical use means adding "root=/dev/mtdblock0" to kernel boot arguments. >> Can we get this reverted? > > Yes, of course. Miquel/Richard/Vignesh, should I send a revert or > can you just apply one with Greg's explanation and my Ack? Thanks Greg