mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-05 11:00:15 +00:00
7985cdf74b
By now the code to only have a single page table level with 64k page size and 42 bit address space is no longer used by any board in tree, so we can safely remove it. To clean up code, move the layerscape mmu code to the new defines, removing redundant field definitions. Signed-off-by: Alexander Graf <agraf@suse.de>
49 lines
1.8 KiB
Text
49 lines
1.8 KiB
Text
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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