1 files changed, 131 insertions, 0 deletions
diff --git a/contrib/loaders/flash/pic32mx.s b/contrib/loaders/flash/pic32mx.s
new file mode 100644
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+/***************************************************************************
+ *   Copyright (C) 2010 by Spencer Oliver                                  *
+ *   spen@spen-soft.co.uk                                                  *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ ***************************************************************************/
+
+	.text
+	.set noreorder
+	.set noat
+
+/* params:
+ * $a0 src adr - ram + result
+ * $a1 dest adr - flash
+ * $a2 count (32bit words)
+ * vars
+ *
+ * temps:
+ * $t0, $t1, $t2, $t3, $t4, $t5
+ * $s0, $s1, $s3, $s4, $s5
+ */
+
+	.type main, @function
+	.global main
+
+.ent main
+main:
+	/* setup constants */
+	lui		$t0, 0xaa99
+	ori		$t0, 0x6655				/* NVMKEY1 */
+	lui		$t1, 0x5566
+	ori		$t1, 0x99AA				/* NVMKEY2 */
+	lui		$t2, 0xBF80
+	ori		$t2, 0xF400				/* NVMCON */
+	ori		$t3, $zero, 0x4003		/* NVMCON row write cmd */
+	ori		$t4, $zero, 0x8000		/* NVMCON start cmd */
+
+write_row:
+	/* can we perform a row write: 128 32bit words */
+	sltiu	$s3, $a2, 128
+	bne		$s3, $zero, write_word
+	ori		$t5, $zero, 0x4000		/* NVMCON clear cmd */
+
+	/* perform row write 512 bytes */
+	sw		$a1, 32($t2)	/* set NVMADDR with dest addr - real addr */
+	sw		$a0, 64($t2)	/* set NVMSRCADDR with src addr - real addr */
+
+	bal		progflash
+	addiu	$a0, $a0, 512
+	addiu	$a1, $a1, 512
+	beq		$zero, $zero, write_row
+	addiu	$a2, $a2, -128
+
+write_word:
+	/* write 32bit words */
+	lui		$s5, 0xa000
+	ori		$s5, 0x0000
+	or		$a0, $a0, $s5			/* convert to virtual addr */
+
+	beq		$zero, $zero, next_word
+	ori		$t3, $zero, 0x4001		/* NVMCON word write cmd */
+
+prog_word:
+	lw		$s4, 0($a0)		/* load data - from virtual addr */
+	sw		$s4, 48($t2)	/* set NVMDATA with data */
+	sw		$a1, 32($t2)	/* set NVMADDR with dest addr - real addr */
+
+	bal		progflash
+	addiu	$a0, $a0, 4
+	addiu	$a1, $a1, 4
+	addiu	$a2, $a2, -1
+next_word:
+	bne		$a2, $zero, prog_word
+	nop
+
+done:
+	beq		$zero, $zero, exit
+	addiu	$a0, $zero, 0
+
+error:
+	/* save result to $a0 */
+	addiu	$a0, $s1, 0
+	
+exit:
+	sdbbp
+.end main
+
+	.type progflash, @function
+	.global progflash
+
+.ent progflash
+progflash:
+	sw		$t3, 0($t2)		/* set NVMWREN */
+	sw		$t0, 16($t2)	/* write NVMKEY1 */
+	sw		$t1, 16($t2)	/* write NVMKEY2 */
+	sw		$t4, 8($t2)		/* start operation */
+
+waitflash:
+	lw		$s0, 0($t2)
+	and		$s0, $s0, $t4
+	bne		$s0, $zero, waitflash
+	nop
+
+	/* following is to comply with errata #34
+	 * 500ns delay required */
+	nop
+	nop
+	nop
+	nop
+	/* check for errors */
+	lw		$s1, 0($t2)
+	andi	$s1, $zero, 0x3000
+	bne		$s1, $zero, error
+	sw		$t5, 4($t2)		/* clear NVMWREN */
+	jr		$ra
+	nop
+	
+.end progflash