stand/pbsdboot/tx39xx.c

/* $NetBSD: */

/*-
 * Copyright (c) 1999 Shin Takemura, UCHIYAMA Yasushi
 * All rights reserved.
 *
 * This software is part of the PocketBSD.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the PocketBSD project
 *	and its contributors.
 * 4. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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 <pbsdboot.h>

extern void tx39xx_asm_code();
extern void tx39xx_asm_code_end();
void tx39xx_asm_code_holder __P((void));

void
tx39xx_init(SYSTEM_INFO *info)
{
	/* 4KByte page */
	system_info.si_pagesize = info->dwPageSize;
	/* DRAM Bank 0/1 physical addr range */
	system_info.si_dramstart = 0x04000000;
	system_info.si_drammaxsize = 0x04000000;
	/* Pointer for bootstrap code */
	system_info.si_asmcode = (unsigned char*)tx39xx_asm_code;
	system_info.si_asmcodelen = (unsigned char*)tx39xx_asm_code_end
		- system_info.si_asmcode;
	system_info.si_boot = mips_boot;
}

void
tx39xx_asm_code_holder()
{
/*
 * void
 * startprog(register struct map_s *map)
 * {
 *   register unsigned char *addr;
 *   register unsigned char *p;
 *   register int i;
 *
 *   addr = map->base;
 *   i = 0;
 *   while (p = map->leaf[i / map->leafsize][i % map->leafsize]) {
 *     register unsigned char *pe = p + map->pagesize;
 *     while (p < pe) {
 *       *addr++ = *p++;
 *     }
 *     i++;
 *   }
 * }
 *
 *  register assignment:
 *    struct map_s *map		a0
 *    unsigned char *addr	a1
 *    unsigned char *p		a2
 *    unsigned char *pe		a3
 *    int i			t0
 *
 * struct map_s {
 *   caddr_t entry;	+0
 *   caddr_t base;	+4
 *   int pagesize;	+8
 *   int leafsize;	+12
 *   int nleaves;	+16
 *   caddr_t arg0;	+20

 *   caddr_t arg1;  +24

 *   caddr_t arg2;	+28

 *   caddr_t arg3;	+32

 *   caddr_t *leaf[32];	+36
 *
 */
	__asm(
		"	.set noreorder;	"
		"	.globl tx39xx_asm_code;"
		"tx39xx_asm_code:"
		"	lui	a0, 0x0000;	"
		"	ori	a0, 0x0000;	"

/* addr = map->base;	*/
		"lw	a1, 4(a0);"

/*   i = 0;		*/
		"ori	t0, zero, 0;"

		" loop_start:"

/*   while (p = map->leaf[i / map->leafsize][i % map->leafsize]) { */
/*   t1 = map->leafsize */
		"lw	t1, 12(a0);"

/*   lo = i / map->leafsize, hi = i % map->leafsize */
		"addu	t3, zero, t0;"
		"div	t3, t1;"
/*   t2 = map->leaf */
		"addiu	t2, a0, 36;"
/*   t3 = i / map->leafsize */
		"nop;"
		"mflo	t3;"
/*   t2 = map->leaf[i / map->leafsize] */
		"sll	t3, t3, 2;"
		"addu	t2, t2, t3;"
		"lw	t2, 0(t2);"
/*   t3 = i % map->leafsize */
		"mfhi	t3;"

/*   p = map->leaf[i / map->leafsize][i % map->leafsize] */
		"sll	t3, t3, 2;"
		"addu	t2, t2, t3;"
		"lw	a2, 0(t2);"

/*		if (p == NULL) {	*/
/*			break;			*/
/*		}					*/
		"beq	a2, zero, loop_end;"
		"nop;"

/*     register unsigned char *pe = p + map->pagesize; */
		"lw	t1, 8(a0);"
		"add	a3, a2, t1;"

/*		while (p < pe) {		*/
		"loop_start2:"
		"sltu        t1, a2, a3;"
		"beq         zero,t1,loop_end2;"
		"nop;"

/*			*addr++ = *p++;	*/
		"lw	t1, 0(a2);"
		"sw	t1, 0(a1);"
		"addi	a2, a2, 4;"
		"addi	a1, a1, 4;"

/*		}	*/
		"beq	zero, zero, loop_start2;"
		"nop;"

/*     i++;	*/
		"loop_end2:"
		"addi	t0, t0, 1;"
		"beq	zero, zero, loop_start;"
		"nop;"

		" loop_end:"

	/*
	 * Flush D-cache. TX3912 is write-through cache. no need to flush.
	 */
#if notyet
	/* Flush I-cache */
		".space 32768;"
#endif
	/* Jump to kernel entry */
		"lw	t0, 0(a0);"		/* entry addr */
		"lw	a1, 24(a0);"	/* arg1 */
		"lw	a2, 28(a0);"	/* arg2 */
		"lw	a3, 32(a0);"	/* arg3 */
		"lw	a0, 20(a0);"	/* arg0 */
		"jr	t0;"
		"nop;"

		".globl tx39xx_asm_code_end;"
		"tx39xx_asm_code_end: nop;"
		".set reorder;	"
	);
}