From d5b6e91ba2cac6cb0a2f7437fdbbe792d1acb387 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 3 Nov 2021 21:09:20 -0600 Subject: bloblist: Support allocating the bloblist Typically the bloblist is positioned at a fixed address in memory until relocation. This is convenient when it is set up in SPL or before relocation. But for EFI we want to set it up only when U-Boot proper is running. Add a way to allocate it using malloc() and update the documentation to cover this aspect of bloblist. Note there are no tests of this feature at present, nor any direct testing of bloblist_init(). This can be added, e.g. by making this option controllable at runtime. Signed-off-by: Simon Glass --- doc/develop/bloblist.rst | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'doc') diff --git a/doc/develop/bloblist.rst b/doc/develop/bloblist.rst index 317ebc4919..47274cf8e2 100644 --- a/doc/develop/bloblist.rst +++ b/doc/develop/bloblist.rst @@ -59,6 +59,22 @@ Bloblist provides a fairly simple API which allows blobs to be created and found. All access is via the blob's tag. Blob records are zeroed when added. +Placing the bloblist +-------------------- + +The bloblist is typically positioned at a fixed address by TPL, or SPL. This +is controlled by `CONFIG_BLOBLIST_ADDR`. But in some cases it is preferable to +allocate the bloblist in the malloc() space. Use the `CONFIG_BLOBLIST_ALLOC` +option to enable this. + +The bloblist is automatically relocated as part of U-Boot relocation. Sometimes +it is useful to expand the bloblist in U-Boot proper, since it may want to add +information for use by Linux. Note that this does not mean that Linux needs to +know anything about the bloblist format, just that it is convenient to use +bloblist to place things contiguously in memory. Set +`CONFIG_BLOBLIST_SIZE_RELOC` to define the expanded size, if needed. + + Finishing the bloblist ---------------------- -- cgit v1.2.3