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b=itu4/rge2gUT/OtuxyXIk1iOld i3yiUJPnG5C6kovEpiu8XsOs1b1ag2rYXmpsB+w9/4mlAPEh9+hTz7nkrrFZ5QLlsMzPd965nGzUA p2FKri/K4oyhpzVljChq7To0F1sswBIjbT4WDadRnPyXFpmp7ZwQ5nc9SN2xgofFRBLY=; Received: from [95.248.141.113] (port=61851 helo=bywater) by esm19.siteground.biz with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.98.1) (envelope-from ) id 1vdDZH-000000004u2-1hq5; Tue, 06 Jan 2026 20:22:15 +0000 Date: Tue, 6 Jan 2026 21:22:13 +0100 From: Francesco Valla To: Geert Uytterhoeven Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jonathan Corbet , Jocelyn Falempe , Javier Martinez Canillas , Sam Ravnborg , Mario Limonciello , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-embedded@vger.kernel.org Subject: Re: [PATCH RFC v2 1/3] drm: client: add splash client Message-ID: References: <20260106-drm_client_splash-v2-0-6e86a7434b59@valla.it> <20260106-drm_client_splash-v2-1-6e86a7434b59@valla.it> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - esm19.siteground.biz X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - valla.it X-Source: X-Source-Args: X-Source-Dir: X-SGantispam-id: 90cfa2c2116e2fd882e48eae592b53ca AntiSpam-DLS: false AntiSpam-DLSP: AntiSpam-DLSRS: AntiSpam-TS: 1.0 CFBL-Address: feedback@antispam.mailspamprotection.com; report=arf CFBL-Feedback-ID: 1vdDZf-0000000EtZP-14O0-feedback@antispam.mailspamprotection.com Authentication-Results: outgoing.instance-europe-west4-fg2f.prod.antispam.mailspamprotection.com; iprev=pass (214.173.214.35.bc.googleusercontent.com) smtp.remote-ip=35.214.173.214; auth=pass (LOGIN) smtp.auth=esm19.siteground.biz; dkim=pass header.d=valla.it header.s=default header.a=rsa-sha256; arc=none Hi Geert, On Tue, Jan 06, 2026 at 03:47:49PM +0100, Geert Uytterhoeven wrote: > Hi Franceso, > > On Tue, 6 Jan 2026 at 15:26, Francesco Valla wrote: > > Add a DRM client that draws a simple splash, with possibility to show: > > > > - a colored background; > > - a static BMP image (loaded as firmware); > > - the logo provided by EFI BGRT. > > > > The client is not meant to replace a full-featured bootsplash, but > > rather to remove some complexity (and hopefully boot time) on small > > embedded platforms or on systems with a limited scope (e.g: recovery > > or manufacturing images). > > > > The background color can be set either at build time from a dedicated > > config option or at runtime through the drm_client_lib.splash_color > > command line parameter. Any color in RGB888 format can be used. > > > > If enabled, the static BMP image is loaded using the kernel firmware > > infrastructure; a valid BMP image with 24bpp color and no compression > > is expected. The name of the image can be set through the > > drm_client_lib.splash_bmp kernel command line parameter, with the > > default being 'drm_splash.bmp'. > > > > Just like the existing DRM clients, the splash can be enabled from the > > kernel command line using drm_client_lib.active=splash. > > > > Signed-off-by: Francesco Valla > > Thanks for your patch! > > > --- /dev/null > > +++ b/drivers/gpu/drm/clients/drm_splash.c > > > +#if IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_BMP_SUPPORT) > > There is no need to protect this block with #if, as it does not generate > any code. > This was left here when I moved some code along - I'll remove the guards. > > +#define BMP_FILE_MAGIC_ID 0x4d42 > > + > > +/* BMP header structures copied from drivers/video/fbdev/efifb.c */ > > +struct bmp_file_header { > > + u16 id; > > + u32 file_size; > > + u32 reserved; > > + u32 bitmap_offset; > > +} __packed; > > + > > +struct bmp_dib_header { > > + u32 dib_header_size; > > + s32 width; > > + s32 height; > > + u16 planes; > > + u16 bpp; > > + u32 compression; > > + u32 bitmap_size; > > + u32 horz_resolution; > > + u32 vert_resolution; > > + u32 colors_used; > > + u32 colors_important; > > +} __packed; > > +#endif // CONFIG_DRM_CLIENT_SPLASH_BMP_SUPPORT > > As per [1], all these values are little-endian. Hence they should > be declared as such using le16 or le32, and accessed using > get_unalined_le{16,32}(). > > [1] https://en.wikipedia.org/wiki/BMP_file_format#File_structure > This is obviously right, I'll use proper accessors in next version. I wonder why this is done precisely this way inside the efifb driver, but that's maybe because all EFI platforms are little-endian? > Gr{oetje,eeting}s, > > Geert > Thank you! Reagrds, Francesco