fdt: Set kernaddr if fdt indicates a kernel is present

If kernel-offset is specified in the fdt, set an environment variable
so that scripts can access the attached kernel.

This can be used by a packaging program to tell U-Boot about a kernel
that has been downloaded alongside U-Boot. The value in the fdt is
the offset of the kernel from the start of the U-Boot image, so we can
find it just by adding CONFIG_SYS_TEXT_BASE.

It is then fairly easy to put something like this in the environment
variables in the board header file:

		"if test ${kernaddr} != \"\"; then "\
			"echo \"Using bundled kernel\"; "\
			"bootm ${kernaddr};" \
		"fi; "\
		/* rest of boot sequence follows here */

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/common/main.c b/common/main.c
index 61c6cac882150acaba23f032b2ef4bb14c0d4bca..8052d4222ec82b8ddd9d9b2b0528bfb6ff67c9bd 100644 (file)
--- a/common/main.c
+++ b/common/main.c
@@ -333,6 +333,20 @@ err:
        hang();
 }
 
+static void process_fdt_options(const void *blob)
+{
+       ulong addr;
+
+       /* Add an env variable to point to a kernel payload, if available */
+       addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
+       if (addr)
+               setenv_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
+
+       /* Add an env variable to point to a root disk, if available */
+       addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
+       if (addr)
+               setenv_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
+}
 #endif /* CONFIG_OF_CONTROL */
 
 
@@ -451,6 +465,8 @@ void main_loop (void)
        if (env)
                s = env;
 
+       process_fdt_options(gd->fdt_blob);
+
        /*
         * If the bootsecure option was chosen, use secure_boot_cmd().
         * Always use 'env' in this case, since bootsecure requres that the