Documentation/powerpc/bootwrapper.txt

1 The PowerPC boot wrapper
6 a boot wrapper to make it usable by the system firmware.  There is no
7 standard PowerPC firmware interface, so the boot wrapper is designed to
10 The boot wrapper can be found in the arch/powerpc/boot/ directory.  The
15 others.  U-Boot is typically found on embedded PowerPC hardware, but there
19 The boot wrapper is built from the makefile in arch/powerpc/boot/Makefile and
20 it uses the wrapper script (arch/powerpc/boot/wrapper) to generate target
25 			U-Boot (for versions that don't understand the device
27 			the image.  The boot wrapper, kernel and device tree
28 			are all embedded inside the U-Boot uImage file format
29 			with boot wrapper code that extracts data from the old
33 			bd_info structure used in the old U-Boot interfaces,
35 			U-Boot platform has a different platform init file
39 			arch/powerpc/boot/cuboot.*.c.  Selection of the correct
55 			file named arch/powerpc/boot/<platform>.c; but this
83 			arch/powerpc/boot/virtex405-head.S for details.
87    uImage:		Native image format used by U-Boot.  The uImage target
88 			does not add any boot code.  It just wraps a compressed
90 			requires a version of U-Boot that is able to pass
91 			a device tree to the kernel at boot.  If using an older
92 			version of U-Boot, then you need to use a cuImage
97 			expects firmware to provide the device tree at boot.
103 arch/powerpc/boot/dts/ directory.  The Makefile selects the correct device
106 build system will use arch/powerpc/boot/dts/walnut.dts to build
107 treeImage.walnut and arch/powerpc/boot/dts/virtex405-ml403.dts to build
112 Default images are selected by the boot wrapper Makefile
113 (arch/powerpc/boot/Makefile) by adding targets to the $image-y variable.  Look
120 It also means that the boot wrapper must be able to wrap for many kinds of
122 conditional compilation code (#ifdef, etc) in the boot wrapper source code.
123 All of the boot wrapper pieces are buildable at any time regardless of the
130 script' (found in arch/powerpc/boot/wrapper) is called by the Makefile and