[POWERPC] zImage: Cleanup and improve prep_kernel()

This patch rewrites prep_kernel() in the zImage wrapper code to be
clearer and more flexible.  Notable changes:

	- Handling of the initrd image from prep_kernel() has moved
into a new prep_initrd() function.
	- The address of the initrd image is now added as device tree
properties, as the kernel expects.
	- We only copy a packaged initrd image to a new location if it
is in danger of being clobbered when the kernel moves to its final
location, instead of always.
	- By default we decompress the kernel directly to address 0,
instead of requiring it to relocate itself.  Platforms (such as OF)
where doing this could clobber still-live firmware data structures can
override the vmlinux_alloc hook to provide an alternate place to
decompress the kernel.
	- We no longer pass lots of information between functions in
global variables.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/powerpc/boot/of.c b/arch/powerpc/boot/of.c
index 0182f38..044f347 100644
--- a/arch/powerpc/boot/of.c
+++ b/arch/powerpc/boot/of.c
@@ -208,6 +208,17 @@ static void of_image_hdr(const void *hdr)
 	}
 }
 
+static void *of_vmlinux_alloc(unsigned long size)
+{
+	void *p = malloc(size);
+
+	if (!p) {
+		printf("Can't allocate memory for kernel image!\n\r");
+		exit();
+	}
+	return p;
+}
+
 static void of_exit(void)
 {
 	call_prom("exit", 0, 0);
@@ -261,6 +272,7 @@ int platform_init(void *promptr, char *dt_blob_start, char *dt_blob_end)
 	platform_ops.image_hdr = of_image_hdr;
 	platform_ops.malloc = of_try_claim;
 	platform_ops.exit = of_exit;
+	platform_ops.vmlinux_alloc = of_vmlinux_alloc;
 
 	dt_ops.finddevice = of_finddevice;
 	dt_ops.getprop = of_getprop;