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/efi.h b/include/efi.h
index d005cb6..f9bbb17 100644
--- a/include/efi.h
+++ b/include/efi.h
@@ -705,4 +705,17 @@
*/
int efi_get_pxe_arch(void);
+/**
+ * fdt_efi_pmem_setup() - Pmem setup in DT and EFI memory map
+ * @fdt: Devicetree to add the pmem nodes to
+ *
+ * Iterate through all the blkmap devices, look for BLKMAP_MEM devices,
+ * and add pmem nodes corresponding to the blkmap slice to the
+ * devicetree along with removing the corresponding region from the
+ * EFI memory map.
+ *
+ * Returns: 0 on success, negative error on failure
+ */
+int fdt_efi_pmem_setup(void *fdt);
+
#endif /* _LINUX_EFI_H */