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U-Boot for arm64
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Summary
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=======
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No hardware platform of arm64 is available now. The U-Boot is
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simulated on Foundation Model and Fast Model for ARMv8.
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Notes
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=====
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1. Currenly, U-Boot run at the highest exception level processor
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supported and jump to EL2 or optionally EL1 before enter OS.
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2. U-Boot for arm64 is compiled with AArch64-gcc. AArch64-gcc
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use rela relocation format, a tool(tools/relocate-rela) by Scott Wood
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is used to encode the initial addend of rela to u-boot.bin. After running,
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the U-Boot will be relocated to destination again.
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3. Fdt should be placed at a 2-megabyte boundary and within the first 512
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megabytes from the start of the kernel image. So, fdt_high should be
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defined specially.
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Please reference linux/Documentation/arm64/booting.txt for detail.
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4. Spin-table is used to wake up secondary processors. One location
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(or per processor location) is defined to hold the kernel entry point
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for secondary processors. It must be ensured that the location is
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accessible and zero immediately after secondary processor
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enter slave_cpu branch execution in start.S. The location address
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is encoded in cpu node of DTS. Linux kernel store the entry point
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of secondary processors to it and send event to wakeup secondary
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processors.
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Please reference linux/Documentation/arm64/booting.txt for detail.
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5. Generic board is supported.
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6. CONFIG_ARM64 instead of CONFIG_ARMV8 is used to distinguish aarch64 and
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aarch32 specific codes.
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Contributor
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===========
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Tom Rini <trini@ti.com>
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Scott Wood <scottwood@freescale.com>
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York Sun <yorksun@freescale.com>
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Simon Glass <sjg@chromium.org>
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Sharma Bhupesh <bhupesh.sharma@freescale.com>
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Rob Herring <robherring2@gmail.com>
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Sergey Temerkhanov <s.temerkhanov@gmail.com>
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