/*
 * Startup glue code to uncompress the kernel
 *
 *   (C) 2017 Helge Deller <deller@gmx.de>
 */

#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>
#include <asm/psw.h>
#include <asm/pdc.h>
#include <asm/assembly.h>
#include "sizes.h"

#define BOOTADDR(x)     (x)

#ifndef CONFIG_64BIT
        .import $global$                /* forward declaration */
#endif /*!CONFIG_64BIT*/

        __HEAD

ENTRY(startup)
         .level PA_ASM_LEVEL

#define PSW_W_SM        0x200
#define PSW_W_BIT       36

        ;! nuke the W bit, saving original value
        .level 2.0
        rsm     PSW_W_SM, %r1

        .level 1.1
        extrw,u %r1, PSW_W_BIT-32, 1, %r1
        copy    %r1, %arg0

        /* Make sure sr4-sr7 are set to zero for the kernel address space */
        mtsp    %r0,%sr4
        mtsp    %r0,%sr5
        mtsp    %r0,%sr6
        mtsp    %r0,%sr7

        /* Clear BSS */

        .import _bss,data
        .import _ebss,data

        load32  BOOTADDR(_bss),%r3
        load32  BOOTADDR(_ebss),%r4
        ldo     FRAME_SIZE(%r4),%sp     /* stack at end of bss */
$bss_loop:
        cmpb,<<,n %r3,%r4,$bss_loop
        stw,ma  %r0,4(%r3)

        /* Initialize the global data pointer */
        loadgp

        /* arg0..arg4 were set by palo. */
        copy    %arg1, %r6              /* command line */
        copy    %arg2, %r7              /* rd-start */
        copy    %arg3, %r8              /* rd-end */
        load32  BOOTADDR(decompress_kernel),%r3

#ifdef CONFIG_64BIT
        .level PA_ASM_LEVEL
        ssm     PSW_W_SM, %r0           /* set W-bit */
        depdi   0, 31, 32, %r3
#endif
        load32  BOOTADDR(startup_continue), %r2
        bv,n    0(%r3)

startup_continue:
#ifdef CONFIG_64BIT
        .level PA_ASM_LEVEL
        rsm     PSW_W_SM, %r0           /* clear W-bit */
#endif

        load32  KERNEL_BINARY_TEXT_START, %arg0 /* free mem */
        copy    %r6, %arg1              /* command line */
        copy    %r7, %arg2              /* rd-start */
        copy    %r8, %arg3              /* rd-end */

        bv,n    0(%ret0)
END(startup)