blkmap: pass information on ISO image to the OS
The EFI HTTP boot puts the ISO installer image at some location in
memory. Information about this image has to be passed on to the OS
kernel, which is done by adding a persistent memory(pmem) node to the
devicetree(DT) that is passed to the OS. The OS kernel then gets
information about the presence of this ISO image and proceeds with the
installation.
In U-Boot, this ISO image gets mounted as a memory mapped blkmap
device slice, with the 'preserve' attribute. Add a helper function
which iterates through all such slices, and invokes a callback. The
callback adds the pmem node to the DT and removes the corresponding
memory region from the EFI memory map. Invoke this helper function as
part of the DT fixup which happens before booting the OS.
Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/include/blkmap.h b/include/blkmap.h
index 754d867..57555fd 100644
--- a/include/blkmap.h
+++ b/include/blkmap.h
@@ -7,6 +7,7 @@
#ifndef _BLKMAP_H
#define _BLKMAP_H
+#include <blk.h>
#include <dm/lists.h>
/**
@@ -104,4 +105,32 @@
int blkmap_create_ramdisk(const char *label, ulong image_addr, ulong image_size,
struct udevice **devp);
+/**
+ * blkmap_get_preserved_pmem_slices() - Look for memory mapped preserved slices
+ * @cb: Callback function to call for the blkmap slice
+ * @ctx: Argument to be passed to the callback function
+ *
+ * The function is used to iterate through all the blkmap slices, looking
+ * specifically for memory mapped blkmap mapping which has been
+ * created with the preserve attribute. The function looks for such slices
+ * with the relevant attributes and then calls the callback function which
+ * then does additional configuration as needed. The callback function is
+ * invoked for all the discovered slices, unless there is an error returned
+ * by the callback, in which case the function returns that error.
+ *
+ * The callback function has the following arguments
+ * @ctx: Argument to be passed to the callback function
+ * @addr: Start address of the memory mapped slice
+ * @size: Size of the memory mapped slice
+ *
+ * Typically, the callback will perform some configuration needed for the
+ * information passed on to it. An example of this would be setting up the
+ * pmem node in a device-tree(passed through the ctx argument) with the
+ * parameters passed on to the callback.
+ *
+ * Return: 0 on success, negative error on failure
+ */
+int blkmap_get_preserved_pmem_slices(int (*cb)(void *ctx, u64 addr,
+ u64 size), void *ctx);
+
#endif /* _BLKMAP_H */