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diff --git a/contrib/loaders/flash/stm32x.S b/contrib/loaders/flash/stm32x.S
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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
+ .syntax unified
+ .cpu cortex-m3
+ .thumb
+ .thumb_func
+ .global write
+
+/*
+ r0 - source address
+ r1 - target address
+ r2 - count (halfword-16bit)
+ r3 - result
+ r4 - temp
+*/
+
+#define STM32_FLASH_CR_OFFSET 0x10 /* offset of CR register in FLASH struct */
+#define STM32_FLASH_SR_OFFSET 0x0c /* offset of CR register in FLASH struct */
+
+write:
+ ldr r4, STM32_FLASH_BASE
+write_half_word:
+ movs r3, #0x01
+ str r3, [r4, #STM32_FLASH_CR_OFFSET] /* PG (bit0) == 1 => flash programming enabled */
+ ldrh r3, [r0], #0x02 /* read one half-word from src, increment ptr */
+ strh r3, [r1], #0x02 /* write one half-word from src, increment ptr */
+busy:
+ ldr r3, [r4, #STM32_FLASH_SR_OFFSET]
+ tst r3, #0x01 /* BSY (bit0) == 1 => operation in progress */
+ beq busy /* wait more... */
+ tst r3, #0x14 /* PGERR (bit2) == 1 or WRPRTERR (bit4) == 1 => error */
+ bne exit /* fail... */
+ subs r2, r2, #0x01 /* decrement counter */
+ bne write_half_word /* write next half-word if anything left */
+exit:
+ bkpt #0x00
+
+STM32_FLASH_BASE: .word 0x40022000 /* base address of FLASH struct */