tinyriscv-openocd/contrib/loaders/flash/lpcspifi_init.S

103 lines
4.2 KiB
ArmAsm

/***************************************************************************
* Copyright (C) 2012 by George Harris *
* george@luminairecoffee.com *
* *
* 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. *
***************************************************************************/
/***************************************************************************
* This is an algorithm for the LPC43xx family (and probably the LPC18xx *
* family as well, though they have not been tested) that will initialize *
* memory-mapped SPI flash accesses. Unfortunately NXP has published *
* neither the ROM source code that performs this initialization nor the *
* register descriptions necessary to do so, so this code is necessary to *
* call into the ROM SPIFI API. *
***************************************************************************/
.text
.syntax unified
.arch armv7-m
.thumb
.thumb_func
.align 2
/*
* Params :
* r0 = spifi clock speed
*/
#define IOCONFIG_BASE_HIGH 0x4008
#define IOCONFIG_BASE_LOW 0x6000
#define IOCONFIG_SCK_OFFSET 0x18c
#define IOCONFIG_HOLD_OFFSET 0x190
#define IOCONFIG_WP_OFFSET 0x194
#define IOCONFIG_MISO_OFFSET 0x198
#define IOCONFIG_MOSI_OFFSET 0x19c
#define IOCONFIG_CS_OFFSET 0x1a0
#define SPIFI_ROM_TABLE_BASE_HIGH 0x1040
#define SPIFI_ROM_TABLE_BASE_LOW 0x0118
code:
mov.w r8, r0
sub sp, #0x84
add r7, sp, #0x0
/* Initialize SPIFI pins */
mov.w r3, #IOCONFIG_BASE_LOW
movt r3, #IOCONFIG_BASE_HIGH
mov.w r2, #0xf3
str.w r2, [r3, #IOCONFIG_SCK_OFFSET]
mov.w r3, #IOCONFIG_BASE_LOW
movt r3, #IOCONFIG_BASE_HIGH
mov.w r2, #IOCONFIG_BASE_LOW
movt r2, #IOCONFIG_BASE_HIGH
mov.w r1, #IOCONFIG_BASE_LOW
movt r1, #IOCONFIG_BASE_HIGH
mov.w r0, #IOCONFIG_BASE_LOW
movt r0, #IOCONFIG_BASE_HIGH
mov.w r4, #0xd3
str.w r4, [r0, #IOCONFIG_MOSI_OFFSET]
mov r0, r4
str.w r0, [r1, #IOCONFIG_MISO_OFFSET]
mov r1, r0
str.w r1, [r2, #IOCONFIG_WP_OFFSET]
str.w r1, [r3, #IOCONFIG_HOLD_OFFSET]
mov.w r3, #IOCONFIG_BASE_LOW
movt r3, #IOCONFIG_BASE_HIGH
mov.w r2, #0x13
str.w r2, [r3, #IOCONFIG_CS_OFFSET]
/* Perform SPIFI init. See spifi_rom_api.h (in NXP lpc43xx driver package) for details */
/* on initialization arguments. */
movw r3, #SPIFI_ROM_TABLE_BASE_LOW /* The ROM API table is located @ 0x10400118, and */
movt r3, #SPIFI_ROM_TABLE_BASE_HIGH /* the first pointer in the struct is to the init function. */
ldr r3, [r3, #0x0]
ldr r4, [r3, #0x0] /* Grab the init function pointer from the table */
/* Set up function arguments */
movw r0, #0x3b4
movt r0, #0x1000 /* Pointer to a SPIFI data struct that we don't care about */
mov.w r1, #0x3 /* "csHigh". Not 100% sure what this does. */
mov.w r2, #0xc0 /* The configuration word: S_RCVCLOCK | S_FULLCLK */
mov.w r3, r8 /* SPIFI clock speed (12MHz) */
blx r4 /* Call the init function */
b done
done:
bkpt #0
.end