flash/nor, contrib/loaders: add stm32 loaders Makefile and generated .inc

[openocd] / contrib / loaders / flash / stm32 / stm32h7x.S

diff --git a/contrib/loaders/flash/stm32/stm32h7x.S b/contrib/loaders/flash/stm32/stm32h7x.S
new file mode 100644 (file)
index 0000000..f910bfb
--- /dev/null
+++ b/contrib/loaders/flash/stm32/stm32h7x.S
@@ -0,0 +1,108 @@
+/***************************************************************************
+ *   Copyright (C) 2017 by STMicroelectronics                              *
+ *                                                                         *
+ *   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.                                        *
+ ***************************************************************************/
+
+       .text
+       .syntax unified
+       .cpu cortex-m7
+       .thumb
+
+/*
+ * Code limitations:
+ * The workarea must have size multiple of 4 bytes, since R/W
+ * operations are all at 32 bits.
+ * The workarea must be big enough to contain 32 bytes of data,
+ * thus the minimum size is (rp, wp, data) = 4 + 4 + 32 = 40 bytes.
+ * To benefit from concurrent host write-to-buffer and target
+ * write-to-flash, the workarea must be way bigger than the minimum.
+ */
+
+/*
+ * Params :
+ * r0 = workarea start, status (out)
+ * r1 = workarea end
+ * r2 = target address
+ * r3 = count (256 bit words)
+ * r4 = flash reg base
+ *
+ * Clobbered:
+ * r5 - rp
+ * r6 - wp, status, tmp
+ * r7 - loop index, tmp
+ */
+
+#define STM32_FLASH_CR_OFFSET  0x0C    /* offset of CR register in FLASH struct */
+#define STM32_FLASH_SR_OFFSET  0x10    /* offset of SR register in FLASH struct */
+#define STM32_CR_PROG                  0x00000032      /* PSIZE64 | PG */
+#define STM32_SR_BUSY_MASK             0x00000001      /* BSY */
+#define STM32_SR_ERROR_MASK            0x03ee0000      /* DBECCERR | SNECCERR | RDSERR | RDPERR | OPERR
+                                                                                          | INCERR | STRBERR | PGSERR | WRPERR */
+
+       .thumb_func
+       .global _start
+_start:
+       ldr             r5, [r0, #4]            /* read rp */
+
+wait_fifo:
+       ldr             r6, [r0, #0]            /* read wp */
+       cbz             r6, exit                        /* abort if wp == 0, status = 0 */
+       subs    r6, r6, r5                      /* number of bytes available for read in r6 */
+       ittt    mi                                      /* if wrapped around */
+       addmi   r6, r1                          /* add size of buffer */
+       submi   r6, r0
+       submi   r6, #8
+       cmp             r6, #32                         /* wait until 32 bytes are available */
+       bcc             wait_fifo
+
+       mov             r6, #STM32_CR_PROG
+       str             r6, [r4, #STM32_FLASH_CR_OFFSET]
+
+       mov             r7, #8                          /* program by 8 words = 32 bytes */
+write_flash:
+       ldr             r6, [r5], #0x04         /* read one word from src, increment ptr */
+       str             r6, [r2], #0x04         /* write one word to dst, increment ptr */
+       dsb
+       cmp             r5, r1                          /* if rp >= end of buffer ... */
+       it              cs
+       addcs   r5, r0, #8                      /* ... then wrap at buffer start */
+       subs    r7, r7, #1                      /* decrement loop index */
+       bne             write_flash                     /* loop if not done */
+
+busy:
+       ldr             r6, [r4, #STM32_FLASH_SR_OFFSET]
+       tst             r6, #STM32_SR_BUSY_MASK
+       bne             busy                            /* operation in progress, wait ... */
+
+       ldr             r7, =STM32_SR_ERROR_MASK
+       tst             r6, r7
+       bne             error                           /* fail... */
+
+       str             r5, [r0, #4]            /* store rp */
+       subs    r3, r3, #1                      /* decrement count */
+       bne             wait_fifo                       /* loop if not done */
+       b               exit
+
+error:
+       movs    r7, #0
+       str             r7, [r0, #4]            /* set rp = 0 on error */
+
+exit:
+       mov             r0, r6                          /* return status in r0 */
+       bkpt    #0x00
+
+       .pool
+