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Bin Menga1875592016-02-05 19:30:11 -08001U-Boot for arm64
David Feng0ae76532013-12-14 11:47:35 +08002
3Summary
4=======
Bin Menga1875592016-02-05 19:30:11 -08005No hardware platform of arm64 is available now. The U-Boot is
David Feng0ae76532013-12-14 11:47:35 +08006simulated on Foundation Model and Fast Model for ARMv8.
7
8Notes
9=====
10
Bin Menga1875592016-02-05 19:30:11 -0800111. Currenly, U-Boot run at the highest exception level processor
David Feng0ae76532013-12-14 11:47:35 +080012 supported and jump to EL2 or optionally EL1 before enter OS.
13
Bin Menga1875592016-02-05 19:30:11 -0800142. U-Boot for arm64 is compiled with AArch64-gcc. AArch64-gcc
David Feng0ae76532013-12-14 11:47:35 +080015 use rela relocation format, a tool(tools/relocate-rela) by Scott Wood
16 is used to encode the initial addend of rela to u-boot.bin. After running,
Bin Menga1875592016-02-05 19:30:11 -080017 the U-Boot will be relocated to destination again.
David Feng0ae76532013-12-14 11:47:35 +080018
193. Fdt should be placed at a 2-megabyte boundary and within the first 512
20 megabytes from the start of the kernel image. So, fdt_high should be
21 defined specially.
22 Please reference linux/Documentation/arm64/booting.txt for detail.
23
244. Spin-table is used to wake up secondary processors. One location
25 (or per processor location) is defined to hold the kernel entry point
26 for secondary processors. It must be ensured that the location is
27 accessible and zero immediately after secondary processor
28 enter slave_cpu branch execution in start.S. The location address
29 is encoded in cpu node of DTS. Linux kernel store the entry point
30 of secondary processors to it and send event to wakeup secondary
31 processors.
32 Please reference linux/Documentation/arm64/booting.txt for detail.
33
345. Generic board is supported.
35
366. CONFIG_ARM64 instead of CONFIG_ARMV8 is used to distinguish aarch64 and
37 aarch32 specific codes.
38
Sergey Temerkhanov94f7ff32015-10-14 09:55:45 -070039
40
David Feng0ae76532013-12-14 11:47:35 +080041Contributor
42===========
Sergey Temerkhanov94f7ff32015-10-14 09:55:45 -070043 Tom Rini <trini@ti.com>
44 Scott Wood <scottwood@freescale.com>
45 York Sun <yorksun@freescale.com>
46 Simon Glass <sjg@chromium.org>
47 Sharma Bhupesh <bhupesh.sharma@freescale.com>
48 Rob Herring <robherring2@gmail.com>
49 Sergey Temerkhanov <s.temerkhanov@gmail.com>