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| /* SPDX-License-Identifier: GPL-2.0 */
| #include <asm/core.h>
| #include <asm/regs.h>
| #include <asm/asmmacro.h>
| #include <asm/cacheasm.h>
| /*
| * RB-Data: RedBoot data/bss
| * P: Boot-Parameters
| * L: Kernel-Loader
| *
| * The Linux-Kernel image including the loader must be loaded
| * to a position so that the kernel and the boot parameters
| * can fit in the space before the load address.
| * ______________________________________________________
| * |_RB-Data_|_P_|__________|_L_|___Linux-Kernel___|______|
| * ^
| * ^ Load address
| * ______________________________________________________
| * |___Linux-Kernel___|_P_|_L_|___________________________|
| *
| * The loader copies the parameter to the position that will
| * be the end of the kernel and itself to the end of the
| * parameter list.
| */
|
| /* Make sure we have enough space for the 'uncompressor' */
|
| #define STACK_SIZE 32768
| #define HEAP_SIZE (131072*4)
|
| # a2: Parameter list
| # a3: Size of parameter list
|
| .section .start, "ax"
|
| .globl __start
| /* this must be the first byte of the loader! */
| __start:
| entry sp, 32 # we do not intend to return
| _call0 _start
| __start_a0:
| .align 4
|
| .section .text, "ax"
| .literal_position
| .begin literal_prefix .text
|
| /* put literals in here! */
|
| .globl _start
| _start:
|
| /* 'reset' window registers */
|
| movi a4, 1
| wsr a4, ps
| rsync
|
| rsr a5, windowbase
| ssl a5
| sll a4, a4
| wsr a4, windowstart
| rsync
|
| movi a4, 0x00040000
| wsr a4, ps
| rsync
|
| /* copy the loader to its address
| * Note: The loader itself is a very small piece, so we assume we
| * don't partially overlap. We also assume (even more important)
| * that the kernel image is out of the way. Usually, when the
| * load address of this image is not at an arbitrary address,
| * but aligned to some 10K's we shouldn't overlap.
| */
|
| /* Note: The assembler cannot relax "addi a0, a0, ..." to an
| l32r, so we load to a4 first. */
|
| # addi a4, a0, __start - __start_a0
| # mov a0, a4
|
| movi a4, __start
| movi a5, __start_a0
| add a4, a0, a4
| sub a0, a4, a5
|
| movi a4, __start
| movi a5, __reloc_end
|
| # a0: address where this code has been loaded
| # a4: compiled address of __start
| # a5: compiled end address
|
| mov.n a7, a0
| mov.n a8, a4
|
| 1:
| l32i a10, a7, 0
| l32i a11, a7, 4
| s32i a10, a8, 0
| s32i a11, a8, 4
| l32i a10, a7, 8
| l32i a11, a7, 12
| s32i a10, a8, 8
| s32i a11, a8, 12
| addi a8, a8, 16
| addi a7, a7, 16
| blt a8, a5, 1b
|
|
| /* We have to flush and invalidate the caches here before we jump. */
|
| #if XCHAL_DCACHE_IS_WRITEBACK
|
| ___flush_dcache_all a5 a6
|
| #endif
|
| ___invalidate_icache_all a5 a6
| isync
|
| movi a11, _reloc
| jx a11
|
| .globl _reloc
| _reloc:
|
| /* RedBoot is now at the end of the memory, so we don't have
| * to copy the parameter list. Keep the code around; in case
| * we need it again. */
| #if 0
| # a0: load address
| # a2: start address of parameter list
| # a3: length of parameter list
| # a4: __start
|
| /* copy the parameter list out of the way */
|
| movi a6, _param_start
| add a3, a2, a3
| 2:
| l32i a8, a2, 0
| s32i a8, a6, 0
| addi a2, a2, 4
| addi a6, a6, 4
| blt a2, a3, 2b
| #endif
|
| /* clear BSS section */
| movi a6, __bss_start
| movi a7, __bss_end
| movi.n a5, 0
| 3:
| s32i a5, a6, 0
| addi a6, a6, 4
| blt a6, a7, 3b
|
| movi a5, -16
| movi a1, _stack + STACK_SIZE
| and a1, a1, a5
|
| /* Uncompress the kernel */
|
| # a0: load address
| # a2: boot parameter
| # a4: __start
|
| movi a3, __image_load
| sub a4, a3, a4
| add a8, a0, a4
|
| # a1 Stack
| # a8(a4) Load address of the image
|
| movi a6, _image_start
| movi a10, _image_end
| movi a7, 0x1000000
| sub a11, a10, a6
| movi a9, complen
| s32i a11, a9, 0
|
| movi a0, 0
|
| # a6 destination
| # a7 maximum size of destination
| # a8 source
| # a9 ptr to length
|
| .extern gunzip
| movi a4, gunzip
| beqz a4, 1f
|
| callx4 a4
|
| j 2f
|
|
| # a6 destination start
| # a7 maximum size of destination
| # a8 source start
| # a9 ptr to length
| # a10 destination end
|
| 1:
| l32i a9, a8, 0
| l32i a11, a8, 4
| s32i a9, a6, 0
| s32i a11, a6, 4
| l32i a9, a8, 8
| l32i a11, a8, 12
| s32i a9, a6, 8
| s32i a11, a6, 12
| addi a6, a6, 16
| addi a8, a8, 16
| blt a6, a10, 1b
|
|
| /* jump to the kernel */
| 2:
| #if XCHAL_DCACHE_IS_WRITEBACK
|
| ___flush_dcache_all a5 a6
|
| #endif
|
| ___invalidate_icache_all a5 a6
|
| isync
|
| # a2 Boot parameter list
|
| movi a0, _image_start
| jx a0
|
| .align 16
| .data
| .globl avail_ram
| avail_ram:
| .long _heap
| .globl end_avail
| end_avail:
| .long _heap + HEAP_SIZE
|
| .comm _stack, STACK_SIZE
| .comm _heap, HEAP_SIZE
|
| .globl end_avail
| .comm complen, 4
|
| .end literal_prefix
|
|
