spl: Add a way to declare an SPL image loader

Add a linker list macro which can be used to declare an SPL image loader.
Update spl_load_image() to search available loaders for the correct one.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>

diff --git a/common/spl/spl.c b/common/spl/spl.c
index 167bff0..eb3b808 100644 (file)
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -347,12 +347,32 @@ static void announce_boot_device(u32 boot_device)
 static inline void announce_boot_device(u32 boot_device) { }
 #endif
 
+static struct spl_image_loader *spl_ll_find_loader(uint boot_device)
+{
+       struct spl_image_loader *drv =
+               ll_entry_start(struct spl_image_loader, spl_image_loader);
+       const int n_ents =
+               ll_entry_count(struct spl_image_loader, spl_image_loader);
+       struct spl_image_loader *entry;
+
+       for (entry = drv; entry != drv + n_ents; entry++) {
+               if (boot_device == entry->boot_device)
+                       return entry;
+       }
+
+       /* Not found */
+       return NULL;
+}
+
 static int spl_load_image(u32 boot_device)
 {
        struct spl_boot_device bootdev;
+       struct spl_image_loader *loader = spl_ll_find_loader(boot_device);
 
        bootdev.boot_device = boot_device;
        bootdev.boot_device_name = NULL;
+       if (loader)
+               return loader->load_image(&bootdev);
 
        switch (boot_device) {
 #ifdef CONFIG_SPL_RAM_DEVICE

diff --git a/include/spl.h b/include/spl.h
index 4435089..884fbe6 100644 (file)
--- a/include/spl.h
+++ b/include/spl.h
@@ -149,6 +149,38 @@ struct spl_boot_device {
        const char *boot_device_name;
 };
 
+/**
+ * Holds information about a way of loading an SPL image
+ *
+ * @boot_device: Boot device that this loader supports
+ * @load_image: Function to call to load image
+ */
+struct spl_image_loader {
+       uint boot_device;
+       /**
+        * load_image() - Load an SPL image
+        *
+        * @bootdev: describes the boot device to load from
+        */
+       int (*load_image)(struct spl_boot_device *bootdev);
+};
+
+/* Declare an SPL image loader */
+#define SPL_LOAD_IMAGE(__name)                                 \
+       ll_entry_declare(struct spl_image_loader, __name, spl_image_loader)
+
+/*
+ * __priority is the priority of this method, 0 meaning it will be the top
+ * choice for this device, 9 meaning it is the bottom choice.
+ * __boot_device is the BOOT_DEVICE_... value
+ * __method is the load_image function to call
+ */
+#define SPL_LOAD_IMAGE_METHOD(__priority, __boot_device, __method) \
+       SPL_LOAD_IMAGE(__method ## __priority ## __boot_device) = { \
+               .boot_device = __boot_device, \
+               .load_image = __method, \
+       }
+
 /* NAND SPL functions */
 int spl_nand_load_image(struct spl_boot_device *bootdev);