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[222.228.113.186]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2ddc17ba719sm31428165ad.56.2026.09.21.04.06.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Sep 2026 04:06:54 -0700 (PDT) Message-ID: <17a74e90-27d1-4954-86a8-491267f00cb8@gmail.com> Date: Mon, 21 Sep 2026 20:06:47 +0900 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Yoshifumi SHU Subject: Re: [PATCH v2 00/14] ARM: deprecated platform removal To: arnd@kernel.org Cc: Frank.Li@nxp.com, aaro.koskinen@iki.fi, alexander.sverdlin@siemens.com, alexandre.belloni@bootlin.com, alexandre.torgue@foss.st.com, andreas@kemnade.info, andrew@lunn.ch, arnd@arndb.de, claudiu.beznea@tuxon.dev, conor+dt@kernel.org, david@kernel.org, devicetree@vger.kernel.org, enelsonmoore@gmail.com, festevam@gmail.com, geert@linux-m68k.org, gregory.clement@bootlin.com, imx@lists.linux.dev, kernel@pengutronix.de, khilman@baylibre.com, kmehltretter@gmail.com, kristoffer.ericson@gmail.com, krzk@kernel.org, linusw@kernel.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux@armlinux.org.uk, liviu.dudau@arm.com, lpieralisi@kernel.org, mcoquelin.stm32@gmail.com, nicolas.ferre@microchip.com, npitre@baylibre.com, robert.jarzmik@free.fr, robh@kernel.org, rogerq@kernel.org, s.hauer@pengutronix.de, sebastian.hesselbarth@gmail.com, shawnguo@kernel.org, soc@lists.linux.dev, stefan@agner.ch, sudeep.holla@kernel.org, tony@atomide.com, vz@mleia.com, thehajime@gmail.com References: <20260914140821.1805449-1-arnd@kernel.org> Content-Language: en-US In-Reply-To: <20260914140821.1805449-1-arnd@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Arnd and all, I would like to request that the core Arm Cortex-M support be retained, specifically for v8-M. I'm heavily using Arm Cortex-M / NOMMU Linux for academic research. In particular, I frequently run Linux on newer Arm v8-M (Cortex-M33/M55/M85) processors. However, dropping CONFIG_CPU_V7M also removes support for these newer CPUs. Because v8-M is highly compatible with the older v7-M (Cortex-M3/M4/M7), the v8-M support is tightly coupled with CONFIG_CPU_V7M, despite the name. The major differences are essentially CPU IDs and PMSAv8 MPU support. So I need the majority of CONFIG_CPU_V7M to support Arm v8-M. Regarding platform support, I don't need Linux-side device drivers. In my current setup, Linux runs in a virtualized environment hosted by an RTOS (like Zephyr) and accesses devices through virtio served by the RTOS. I also understand that maintaining legacy MCU platform support is a significant burden. Therefore, I don't object to removing the platform support, though the MPS platform remains convenient for bare-metal testing. I am willing to help maintain this support, including modernizing the relevant code. I can regularly test kernels on real Armv8-M hardware. If an active maintainer is required to keep the support, I am willing to take on that responsibility. Please let me know how I can help keep the support. Thanks, Yoshifumi