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@@ -65,19 +65,13 @@ looks at the connected hardware is beyond the scope of this document.
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The boot loader must ultimately be able to provide a MACH_TYPE_xxx
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value to the kernel. (see linux/arch/arm/tools/mach-types).
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-4. Setup boot data
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-------------------
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+
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+4. Setup the kernel tagged list
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+-------------------------------
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Existing boot loaders: OPTIONAL, HIGHLY RECOMMENDED
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New boot loaders: MANDATORY
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-The boot loader must provide either a tagged list or a dtb image for
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-passing configuration data to the kernel. The physical address of the
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-boot data is passed to the kernel in register r2.
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-
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-4a. Setup the kernel tagged list
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---------------------------------
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-
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The boot loader must create and initialise the kernel tagged list.
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A valid tagged list starts with ATAG_CORE and ends with ATAG_NONE.
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The ATAG_CORE tag may or may not be empty. An empty ATAG_CORE tag
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@@ -107,24 +101,6 @@ The tagged list must be placed in a region of memory where neither
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the kernel decompressor nor initrd 'bootp' program will overwrite
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it. The recommended placement is in the first 16KiB of RAM.
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-4b. Setup the device tree
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--------------------------
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-
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-The boot loader must load a device tree image (dtb) into system ram
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-at a 64bit aligned address and initialize it with the boot data. The
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-dtb format is documented in Documentation/devicetree/booting-without-of.txt.
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-The kernel will look for the dtb magic value of 0xd00dfeed at the dtb
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-physical address to determine if a dtb has been passed instead of a
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-tagged list.
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-
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-The boot loader must pass at a minimum the size and location of the
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-system memory, and the root filesystem location. The dtb must be
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-placed in a region of memory where the kernel decompressor will not
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-overwrite it. The recommended placement is in the first 16KiB of RAM
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-with the caveat that it may not be located at physical address 0 since
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-the kernel interprets a value of 0 in r2 to mean neither a tagged list
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-nor a dtb were passed.
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-
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5. Calling the kernel image
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---------------------------
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@@ -149,8 +125,7 @@ In either case, the following conditions must be met:
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- CPU register settings
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r0 = 0,
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r1 = machine type number discovered in (3) above.
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- r2 = physical address of tagged list in system RAM, or
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- physical address of device tree block (dtb) in system RAM
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+ r2 = physical address of tagged list in system RAM.
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- CPU mode
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All forms of interrupts must be disabled (IRQs and FIQs)
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