/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  linux/arch/sh/boot/compressed/head.S
 *
 *  Copyright (C) 1999 Stuart Menefy
 *  Copyright (C) 2003 SUGIOKA Toshinobu
 */

.text

#include <asm/page.h>

        .global startup
startup:
        /* Load initial status register */
        mov.l   init_sr, r1
        ldc     r1, sr

        /* Move myself to proper location if necessary */
        mova    1f, r0
        mov.l   1f, r2
        cmp/eq  r2, r0
        bt      clear_bss
        sub     r0, r2
        mov.l   bss_start_addr, r0
        mov     #0xffffffe0, r1
        and     r1, r0                  ! align cache line
        mov.l   text_start_addr, r3
        mov     r0, r1
        sub     r2, r1
3:
        mov.l   @r1, r4
        mov.l   @(4,r1), r5
        mov.l   @(8,r1), r6
        mov.l   @(12,r1), r7
        mov.l   @(16,r1), r8
        mov.l   @(20,r1), r9
        mov.l   @(24,r1), r10
        mov.l   @(28,r1), r11
        mov.l   r4, @r0
        mov.l   r5, @(4,r0)
        mov.l   r6, @(8,r0)
        mov.l   r7, @(12,r0)
        mov.l   r8, @(16,r0)
        mov.l   r9, @(20,r0)
        mov.l   r10, @(24,r0)
        mov.l   r11, @(28,r0)
#ifdef CONFIG_CPU_SH4
        ocbwb   @r0
#endif
        cmp/hi  r3, r0
        add     #-32, r0
        bt/s    3b
         add    #-32, r1
        mov.l   2f, r0
        jmp     @r0
         nop

        .align 2
1:      .long   1b
2:      .long   clear_bss
text_start_addr:
        .long   startup

        /* Clear BSS */
clear_bss:
        mov.l   end_addr, r1
        mov.l   bss_start_addr, r2
        mov     #0, r0
l1:
        mov.l   r0, @-r1
        cmp/eq  r1,r2
        bf      l1

        /* Set the initial pointer. */
        mov.l   init_stack_addr, r0
        mov.l   @r0, r15

        /* Decompress the kernel */
        mov.l   decompress_kernel_addr, r0
        jsr     @r0
        nop

        /* Jump to the start of the decompressed kernel */
        mov.l   kernel_start_addr, r0
        jmp     @r0
        nop
        
        .align  2
bss_start_addr:
        .long   __bss_start
end_addr:
        .long   _end
init_sr:
        .long   0x500000F0      /* Privileged mode, Bank=0, Block=1, IMASK=0xF */
kexec_magic:
        .long   0x400000F0      /* magic used by kexec to parse zImage format */
init_stack_addr:
        .long   stack_start
decompress_kernel_addr:
        .long   decompress_kernel
kernel_start_addr:
#ifdef CONFIG_32BIT
        .long   ___pa(_text+PAGE_SIZE)
#else
        .long   _text+PAGE_SIZE
#endif

        .align  9
fake_headers_as_bzImage:
        .word   0
        .ascii  "HdrS"          ! header signature
        .word   0x0202          ! header version number (>= 0x0105)
                                ! or else old loadlin-1.5 will fail)
        .word   0               ! default_switch
        .word   0               ! SETUPSEG
        .word   0x1000
        .word   0               ! pointing to kernel version string
        .byte   0               ! = 0, old one (LILO, Loadlin,
                                ! 0xTV: T=0 for LILO
                                !       V = version
        .byte   1               ! Load flags bzImage=1
        .word   0x8000          ! size to move, when setup is not
        .long   0x100000        ! 0x100000 = default for big kernel
        .long   0               ! address of loaded ramdisk image
        .long   0               # its size in bytes