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>
Some blkmap memory mapped devices might have to be relevant even
after U-Boot passes control to the next image as part of the platform
boot. An example of such a mapping would be an OS installer ISO image,
information for which has to be provided to the OS kernel. Use the
'preserve' attribute for such mappings. The code for adding a pmem
node to the device-tree then checks if this attribute is set, and adds
a node only for mappings which have this attribute.
Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
User needs to call several functions to create the ramdisk
with blkmap.
This adds the utility function to create blkmap device and
mount the ramdisk.
Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Allow a slice of an existing block device to be mapped to a
blkmap. This means that filesystems that are not stored at exact
partition boundaries can be accessed by remapping a slice of the
existing device to a blkmap device.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Allow a slice of RAM to be mapped to a blkmap. This means that RAM can
now be accessed as if it was a block device, meaning that existing
filesystem drivers can now be used to access ramdisks.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
blkmaps are loosely modeled on Linux's device mapper subsystem. The
basic idea is that you can create virtual block devices whose blocks
can be backed by a plethora of sources that are user configurable.
This change just adds the basic infrastructure for creating and
removing blkmap devices. Subsequent changes will extend this to add
support for actual mappings.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
