[PATCH] Barebox does not boot on iMX21ADS board
Sascha Hauer
s.hauer at pengutronix.de
Thu Mar 11 08:55:33 EST 2010
Hi Jaccon,
On Wed, Mar 10, 2010 at 11:50:36PM +0100, Jaccon Bastiaansen wrote:
> Barebox crashes during startup, because the SDRAM controller has not been
> initialized.
Thanks, applied
Sascha
>
> Signed-off-by: Jaccon Bastiaansen <jaccon.bastiaansen at gmail.com>
> ---
> board/imx21ads/lowlevel_init.S | 158 ++++++++++++++++++++++++++--------------
> 1 files changed, 103 insertions(+), 55 deletions(-)
>
> diff --git a/board/imx21ads/lowlevel_init.S b/board/imx21ads/lowlevel_init.S
> index b13ec7b..5df6302 100644
> --- a/board/imx21ads/lowlevel_init.S
> +++ b/board/imx21ads/lowlevel_init.S
> @@ -1,70 +1,118 @@
> /*
> - * For clock initialization, see chapter 6 of the
> - * "i.MX21 Applications Processor Reference Manual, Rev. 3".
> + * Copyright (C) 2010 Jaccon Bastiaansen <jaccon.bastiaansen at gmail.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
> */
>
> #include <config.h>
> #include <mach/imx-regs.h>
>
> -#define writel(val, reg) \
> - ldr r0, =reg; \
> - ldr r1, =val; \
> - str r1, [r0];
> -
> -.macro sdram_init_mx21ads
> -#if 0
> - /* Set precharge command */
> - writel(0x92120300, SDCTL0);
> -
> - /* Issue Precharge all Command */
> - ldr r3, =0xC0200000;
> - ldr r2, [r3];
> -
> - /* Set AutoRefresh command */
> - writel(0x92120300, SDCTL0);
> -
> - /* Issue AutoRefresh command */
> - ldr r3, =0xC0000000;
> - ldr r2, [r3];
> - ldr r2, [r3];
> - ldr r2, [r3];
> - ldr r2, [r3];
> - ldr r2, [r3];
> - ldr r2, [r3];
> - ldr r2, [r3];
> - ldr r2, [r3];
> -
> -
> - /* Set Mode Register */
> - writel(0xB2120300, SDCTL0);
> -#endif
> -.endm
>
> .globl board_init_lowlevel
> board_init_lowlevel:
>
> - mov r10, lr
> +/* Save lr, because it is overwritten by the calls to mem_delay. */
> + mov r5, lr
> +
> +/*
> + * Initialize the AHB-Lite IP Interface (AIPI) module (to enable access to
> + * on chip peripherals) as described in section 7.2 of rev3 of the i.MX21
> + * reference manual.
> + */
> + ldr r0, =AIPI1_PSR0
> + ldr r1, =0x00040304
> + str r1, [r0]
> + ldr r0, =AIPI1_PSR1
> + ldr r1, =0xfffbfcfb
> + str r1, [r0]
> +
> + ldr r0, =AIPI2_PSR0
> + ldr r1, =0x3ffc0000
> + str r1, [r0]
> + ldr r0, =AIPI2_PSR1
> + ldr r1, =0xffffffff
> + str r1, [r0]
>
> - /* ahb lite ip interface */
> - writel(0x00040304, AIPI1_PSR0)
> - writel(0xFFFBFCFB, AIPI1_PSR1)
> - writel(0x00000000, AIPI2_PSR0)
> - writel(0xFFFFFFFF, AIPI2_PSR1)
> +/*
> + * Configure CPU core clock (266MHz), peripheral clock (133MHz) and enable
> + * the clock to peripherals.
> + */
> + ldr r0, =CSCR
> + ldr r1, =0x17180607
> + str r1, [r0]
> +
> + ldr r0, =PCCR1
> + ldr r1, =0x0e000000
> + str r1, [r0]
>
> - /* Set MPLL to 266MHz */
> - writel(0x007B1C73, MPCTL0);
> - /* PLL 133MHz */
> - writel(0x17000607, CSCR);
>
> - /* skip sdram initialization if we run from ram */
> - /* (SDRAM is mapped from C0000000 to C3FFFFFF) */
> - cmp pc, #0xc0000000
> - bls 1f
> - cmp pc, #0xc8000000
> - bhi 1f
> +/*
> + * SDRAM and SDRAM controller configuration
> + */
> +
> + /*
> + * CSD1 not required, because the MX21ADS board only contains 64Mbyte.
> + * CS3 can therefore be made available.
> + */
> + ldr r0, =FMCR
> + ldr r1, =0xffffffc9
> + str r1, [r0]
>
> - mov pc,r10
> -1:
> - sdram_init_mx21ads
> + /* Precharge */
> + ldr r0, =SDCTL0
> + ldr r1, =0x92120300
> + str r1, [r0]
> + ldr r2, =0xc0200000
> + ldr r1, [r2]
> +
> + bl mem_delay
> +
> + /* Auto refresh */
> + ldr r1, =0xa2120300
> + str r1, [r0]
> + ldr r2, =0xc0000000
> + ldr r1, [r2]
> + ldr r1, [r2]
> + ldr r1, [r2]
> + ldr r1, [r2]
> + ldr r1, [r2]
> + ldr r1, [r2]
> + ldr r1, [r2]
> + ldr r1, [r2]
> +
> + /* Set mode register */
> + ldr r1, =0xB2120300
> + str r1, [r0]
> + ldr r1, =0xC0119800
> + ldr r2, [r1]
> +
> + bl mem_delay
> +
> + /* Back to Normal Mode */
> + ldr r1, =0x8212F339
> + str r1, [r0]
> +
> + mov pc, r5
> +
> +/*
> + * spin for a while. we need to wait at least 200 usecs.
> + */
> +mem_delay:
> + mov r4, #0x4000
> +spin: subs r4, r4, #1
> + bne spin
> + mov pc, lr
>
> - mov pc,r10
> --
> 1.6.3.3
>
>
--
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