With CONFIG_LOGO_DT_CLUT224 enabled, look for a node compatible with "linux,boot-logo-clut224" and, when one is present and enabled, use the image it carries in preference to the logos built into the kernel image.
This lets a single kernel image serve several products, or several revisions of one product, that differ only in branding, at the cost of a larger device tree blob. The image is validated while it is parsed: the palette must be at most 224 entries, the pixel data length must match the declared geometry, and every pixel must reference an existing palette entry. A malformed node is reported and ignored, falling back to the built-in logo. The two allocations live for as long as the built-in logos do; they are released from fb_logo_late_init(), next to where the __initdata logos are marked as freed. If the node is absent or disabled, behaviour is unchanged. Signed-off-by: Max Pedraza <[email protected]> --- drivers/video/logo/Kconfig | 13 +++ drivers/video/logo/logo.c | 157 +++++++++++++++++++++++++++++++++++++ 2 files changed, 170 insertions(+) diff --git a/drivers/video/logo/Kconfig b/drivers/video/logo/Kconfig index ce6bb7535..4af349b20 100644 --- a/drivers/video/logo/Kconfig +++ b/drivers/video/logo/Kconfig @@ -70,4 +70,17 @@ config LOGO_SUPERH_CLUT224 depends on SUPERH default y +config LOGO_DT_CLUT224 + bool "224-color logo supplied by the device tree" + depends on OF + help + Look for a boot logo in the device tree, in a node compatible with + "linux,boot-logo-clut224", instead of using one of the logos built + into the kernel image. This allows a single kernel image to be used + by several products that only differ in branding, at the cost of + making the device tree blob larger. + + If no such node is present, or it is disabled, the built-in logo + selected above is used, so saying Y here is safe. If unsure, say N. + endif # LOGO diff --git a/drivers/video/logo/logo.c b/drivers/video/logo/logo.c index 141f15a9a..b4f533df0 100644 --- a/drivers/video/logo/logo.c +++ b/drivers/video/logo/logo.c @@ -11,6 +11,9 @@ */ #include <linux/linux_logo.h> +#include <linux/of.h> +#include <linux/sizes.h> +#include <linux/slab.h> #include <linux/stddef.h> #include <linux/module.h> @@ -22,6 +25,155 @@ static bool nologo; module_param(nologo, bool, 0); MODULE_PARM_DESC(nologo, "Disables startup logo"); +#ifdef CONFIG_LOGO_DT_CLUT224 + +#define LOGO_DT_COMPATIBLE "linux,boot-logo-clut224" +#define LOGO_DT_MAX_CLUT 224 +/* + * The first 32 palette entries are reserved for the console, so the logo + * colours start at index 32. That is an implementation detail of the frame + * buffer layer rather than a property of the image, so the device tree stores + * plain indices and the offset is applied here. + */ +#define LOGO_DT_CLUT_OFFSET 32 +/* Sanity limit on the image size, a device tree is not a good place for more */ +#define LOGO_DT_MAX_PIXELS SZ_32M + +static struct linux_logo logo_dt_clut224 = { + .type = LINUX_LOGO_CLUT224, +}; + +static unsigned char *logo_dt_clut; +static unsigned char *logo_dt_data; + +static int logo_dt_parse(struct device_node *np) +{ + unsigned int clutsize, npixels, i; + unsigned char *clut, *data; + u32 width, height; + int len, ret; + + ret = of_property_read_u32(np, "width", &width); + if (ret) + return ret; + + ret = of_property_read_u32(np, "height", &height); + if (ret) + return ret; + + if (!width || !height || (u64)width * height > LOGO_DT_MAX_PIXELS) + return -EINVAL; + + npixels = width * height; + + len = of_property_count_u8_elems(np, "clut"); + if (len < 3 || len % 3) + return -EINVAL; + + clutsize = len / 3; + if (clutsize > LOGO_DT_MAX_CLUT) + return -EINVAL; + + ret = of_property_count_u8_elems(np, "data"); + if (ret < 0) + return ret; + if ((unsigned int)ret != npixels) + return -EINVAL; + + clut = kmalloc(len, GFP_KERNEL); + if (!clut) + return -ENOMEM; + + data = kmalloc(npixels, GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto err_free_clut; + } + + ret = of_property_read_u8_array(np, "clut", clut, len); + if (ret) + goto err_free_data; + + ret = of_property_read_u8_array(np, "data", data, npixels); + if (ret) + goto err_free_data; + + for (i = 0; i < npixels; i++) { + if (data[i] >= clutsize) { + ret = -ERANGE; + goto err_free_data; + } + data[i] += LOGO_DT_CLUT_OFFSET; + } + + logo_dt_clut = clut; + logo_dt_data = data; + + logo_dt_clut224.width = width; + logo_dt_clut224.height = height; + logo_dt_clut224.clutsize = clutsize; + logo_dt_clut224.clut = clut; + logo_dt_clut224.data = data; + + return 0; + +err_free_data: + kfree(data); +err_free_clut: + kfree(clut); + return ret; +} + +static const struct linux_logo *logo_dt_find(void) +{ + static bool probed; + struct device_node *np; + int ret; + + if (probed) + return logo_dt_data ? &logo_dt_clut224 : NULL; + + probed = true; + + np = of_find_compatible_node(NULL, NULL, LOGO_DT_COMPATIBLE); + if (!np) + return NULL; + + if (of_device_is_available(np)) { + ret = logo_dt_parse(np); + if (ret) + pr_warn("logo: ignoring malformed %pOF node (%d)\n", + np, ret); + } + + of_node_put(np); + + return logo_dt_data ? &logo_dt_clut224 : NULL; +} + +static void logo_dt_free(void) +{ + logo_dt_clut224.clut = NULL; + logo_dt_clut224.data = NULL; + + kfree(logo_dt_clut); + logo_dt_clut = NULL; + + kfree(logo_dt_data); + logo_dt_data = NULL; +} + +#else /* !CONFIG_LOGO_DT_CLUT224 */ + +static inline const struct linux_logo *logo_dt_find(void) +{ + return NULL; +} + +static inline void logo_dt_free(void) { } + +#endif /* CONFIG_LOGO_DT_CLUT224 */ + /* * Logos are located in the initdata, and will be freed in kernel_init. * Use late_init to mark the logos as freed to prevent any further use. @@ -32,6 +184,7 @@ static bool logos_freed; static int __init fb_logo_late_init(void) { logos_freed = true; + logo_dt_free(); return 0; } @@ -71,6 +224,10 @@ const struct linux_logo * __ref fb_find_logo(int depth) } if (depth >= 8) { + /* A logo supplied by the device tree wins over the built-in ones */ + logo = logo_dt_find(); + if (logo) + return logo; #ifdef CONFIG_LOGO_LINUX_CLUT224 /* Generic Linux logo */ logo = &logo_linux_clut224; -- 2.39.5
