/*      $NetBSD: mmnet_start.S,v 1.1 2011/11/04 17:40:48 aymeric Exp $ */
/*
* Copyright (C) 2005, 2006 WIDE Project and SOUM Corporation.
* All rights reserved.
*
* Written by Takashi Kiyohara and Susumu Miki for WIDE Project and SOUM
* Corporation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the name of SOUM Corporation
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT and SOUM CORPORATION ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT AND SOUM CORPORATION
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 2002, 2003  Genetec Corporation.  All rights reserved.
* Written by Hiroyuki Bessho for Genetec Corporation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. The name of Genetec Corporation may not be used to endorse or
*    promote products derived from this software without specific prior
*    written permission.
*
* THIS SOFTWARE IS PROVIDED BY GENETEC CORPORATION ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL GENETEC CORPORATION
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <machine/asm.h>
#include <arm/armreg.h>
#include <arm/arm32/pte.h>
#include <arm/arm32/pmap.h>             /* for PMAP_DOMAIN_KERNEL */

#ifndef SDRAM_START
#define SDRAM_START     0x20000000
#endif

/*
* CPWAIT -- Canonical method to wait for CP15 update.
* NOTE: Clobbers the specified temp reg.
* copied from arm/arm/cpufunc_asm_xscale.S
* XXX: better be in a common header file.
*/
#define CPWAIT_BRANCH                                                    \
       sub     pc, pc, #4

#define CPWAIT(tmp)                                                      \
       mrc     p15, 0, tmp, c2, c0, 0  /* arbitrary read of CP15 */    ;\
       mov     tmp, tmp                /* wait for it to complete */   ;\
       CPWAIT_BRANCH                   /* branch to next insn */

/*
* Kernel start routine for the Propox MMnet 1002
* this code is executed at the very beginning after the kernel is loaded
* by U-Boot.
*/
       .text

       .global _C_LABEL(mmnet_start)
_C_LABEL(mmnet_start):
       /*
        *  Kernel is loaded in SDRAM (0x20200000), and is expected to run
        *  in VA 0xc0200000..
        */
       /* save u-boot's args */
       adr     r4, u_boot_args
       nop
       nop
       nop
       stmia   r4!, {r0, r1, r2, r3}
       nop
       nop
       nop

       /* Calculate RAM size */
       adr     r4, ram_size
       ldr     r0, [r4]
0:
       add     r3, r4, r0
       ldr     r1, [r3]
       cmp     r0, r1
       beq     2f
1:
       add     r0, r0, r0      /* r0 <<= 1 */
       str     r0, [r4]
       b       0b
2:
       mvn     r1, r1          /* r1 ^= 0xffffffff */
       str     r1, [r3]
       ldr     r2, [r4]
       cmp     r1, r2
       beq     3f
       str     r0, [r3]        /* restore */
       b       1b
3:
       str     r0, [r4]

       /* build page table from scratch */
       ldr     r0, Lstartup_pagetable          /* pagetable */
       adr     r4, mmu_init_table
       b       5f

4:
       str     r3, [r0, r2]
       add     r2, r2, #4
       add     r3, r3, #(L1_S_SIZE)
       adds    r1, r1, #-1
       bhi     4b
5:
       ldmia   r4!, {r1, r2, r3}       /* # of sections, PA|attr, VA */
       cmp     r1, #0
       bne     4b

       mcr     p15, 0, r0, c2, c0, 0   /* Set TTB */
       mcr     p15, 0, r0, c8, c7, 0   /* Flush TLB */

       /* Set the Domain Access register.  Very important! */
       mov     r0, #((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT)
       mcr     p15, 0, r0, c3, c0, 0

       /* Enable MMU */
       mrc     p15, 0, r0, c1, c0, 0
       orr     r0, r0, #CPU_CONTROL_SYST_ENABLE
       orr     r0, r0, #CPU_CONTROL_MMU_ENABLE
       mcr     p15, 0, r0, c1, c0, 0
       CPWAIT(r0)

       /* Jump to kernel code in TRUE VA */
       adr     r0, Lstart
       ldr     pc, [r0]

Lstart:
       .word   start

#ifndef STARTUP_PAGETABLE_ADDR
#define STARTUP_PAGETABLE_ADDR 0x20000000       /* aligned 16kByte */
#endif
Lstartup_pagetable:
       .word   STARTUP_PAGETABLE_ADDR

       .globl  _C_LABEL(u_boot_args)
u_boot_args:
       .space  16                      /* r0, r1, r2, r3 */

       .globl  _C_LABEL(ram_size)
ram_size:
       .word   0x04000000              /* 64Mbyte */


#define MMU_INIT(va,pa,n_sec,attr) \
       .word   n_sec                                       ; \
       .word   4 * ((va) >> L1_S_SHIFT)                    ; \
       .word   (pa) | (attr)                               ;

mmu_init_table:
       /* fill all table VA==PA */
       MMU_INIT(0x00000000, 0x00000000,
           1 << (32 - L1_S_SHIFT), L1_TYPE_S | L1_S_AP(AP_KRW))

       /* map SDRAM VA==PA, WT cacheable */
       MMU_INIT(SDRAM_START, SDRAM_START,
           64, L1_TYPE_S | L1_S_C | L1_S_AP(AP_KRW))

       /* map VA 0xc0000000..0xc3ffffff to PA 0x20000000..0x23ffffff */
       MMU_INIT(0xc0000000, SDRAM_START,
           64, L1_TYPE_S | L1_S_C | L1_S_AP(AP_KRW))

       .word   0                       /* end of table */