[U-Boot] [PATCH 3/3] iMX31: Add support to iMX31PDK board boots from NAND Flash

Alan Carvalho de Assis
2008-10-23T12:51:27Z

This patch adds support to iMX31PDK board to boot directly from NAND
Flash. In order to it works the previous patches (which reduces start.S
size and copy NAND code to RAM) need be applied first.

Signed-off-by: Alan Carvalho de Assis <alan.assis@freescale.com>
---
board/freescale/mx31pdk/lowlevel_init.S | 95 +++++++++++++++++++++++++++++-
board/freescale/mx31pdk/u-boot.lds | 3 +
include/configs/mx31pdk.h | 15 +++--
3 files changed, 104 insertions(+), 9 deletions(-)

diff --git a/board/freescale/mx31pdk/lowlevel_init.S
b/board/freescale/mx31pdk/lowlevel_init.S
index f368d10..58f6d3d 100644
--- a/board/freescale/mx31pdk/lowlevel_init.S
+++ b/board/freescale/mx31pdk/lowlevel_init.S
@@ -20,11 +20,98 @@
* MA 02111-1307 USA
*/

-/*
- * This is just to keep the linker happy.
- */
+#include <asm/arch/mx31-regs.h>
+
+.macro REG reg, val
+ ldr r2, =\reg
+ ldr r3, =\val
+ str r3, [r2]
+.endm
+
+.macro REG8 reg, val
+ ldr r2, =\reg
+ ldr r3, =\val
+ strb r3, [r2]
+.endm
+
+.macro DELAY loops
+ ldr r2, =\loops
+1:
+ subs r2, r2, #1
+ nop
+ bcs 1b
+.endm

.globl lowlevel_init
lowlevel_init:
- mov pc, lr
+ /* Store return address on the stack since lr is re-used in this file */
+ /* and all other registers are re-used as well */
+ str lr, [sp]
+
+ /* Also setup the Peripheral Port Remap register inside the core */
+ ldr r0, =ARM_PPMRR /* start from AIPS 2GB region */
+ mcr p15, 0, r0, c15, c2, 4
+
+ REG IPU_CONF, IPU_CONF_DI_EN
+ REG CCM_CCMR, 0x074B0BF5
+
+ DELAY 0x40000
+
+ REG CCM_CCMR, 0x074B0BF5 | CCMR_MPE
+ REG CCM_CCMR, (0x074B0BF5 | CCMR_MPE) & ~CCMR_MDS
+
+ /* Set up clock to 532MHz */
+ REG CCM_PDR0, 0xFF871D58
+ REG CCM_MPCTL, 0x0033280C
+ REG CCM_SPCTL, PLL_PD(1) | PLL_MFD(4) | PLL_MFI(12) | PLL_MFN(1)
+
+ /* Set up CPLD on CS5 */
+ REG CSCR_U(5), 0x0000D843
+ REG CSCR_L(5), 0x22252521
+ REG CSCR_A(5), 0x22220A00
+
+ /* Set up MX31 DDR Memory Controller */
+ REG 0x43FAC26C, 0 /* SDCLK */
+ REG 0x43FAC270, 0 /* CAS */
+ REG 0x43FAC274, 0 /* RAS */
+ REG 0x43FAC27C, 0x1000 /* CS2 CSD0) */
+ REG 0x43FAC284, 0 /* DQM3 */
+ REG 0x43FAC288, 0 /* DQM2, DQM1, DQM0, SD31-SD0, A25-A0, MA10 0x288..0x2DC) */
+ REG 0x43FAC28C, 0
+ REG 0x43FAC290, 0
+ REG 0x43FAC294, 0
+ REG 0x43FAC298, 0
+ REG 0x43FAC29C, 0
+ REG 0x43FAC2A0, 0
+ REG 0x43FAC2A4, 0
+ REG 0x43FAC2A8, 0
+ REG 0x43FAC2AC, 0
+ REG 0x43FAC2B0, 0
+ REG 0x43FAC2B4, 0
+ REG 0x43FAC2B8, 0
+ REG 0x43FAC2BC, 0
+ REG 0x43FAC2C0, 0
+ REG 0x43FAC2C4, 0
+ REG 0x43FAC2C8, 0
+ REG 0x43FAC2CC, 0
+ REG 0x43FAC2D0, 0
+ REG 0x43FAC2D4, 0
+ REG 0x43FAC2D8, 0
+ REG 0x43FAC2DC, 0
+ REG 0xB8001010, 0x00000004
+ REG 0xB8001004, 0x006ac73a
+ REG 0xB8001000, 0x92100000
+ REG 0x80000f00, 0x12344321
+ REG 0xB8001000, 0xa2100000
+ REG 0x80000000, 0x12344321
+ REG 0x80000000, 0x12344321
+ REG 0xB8001000, 0xb2100000
+ REG8 0x80000033, 0xda
+ REG8 0x81000000, 0xff
+ REG 0xB8001000, 0x82226080
+ REG 0x80000000, 0xDEADBEEF
+ REG 0xB8001010, 0x0000000c
+
+ /* Copy from NAND to RAM */
+ b nand_copy

diff --git a/board/freescale/mx31pdk/u-boot.lds
b/board/freescale/mx31pdk/u-boot.lds
index 04a8f77..1cfa3ca 100644
--- a/board/freescale/mx31pdk/u-boot.lds
+++ b/board/freescale/mx31pdk/u-boot.lds
@@ -35,6 +35,9 @@ SECTIONS
.text :
{
cpu/arm1136/start.o (.text)
+ board/freescale/mx31pdk/lowlevel_init.o (.text)
+ cpu/arm1136/mx31/nand_copy.o (.text)
+ . = 2K; /* lowlevel NAND needs to fit in 2KB of NFC buffer */
*(.text)
}

diff --git a/include/configs/mx31pdk.h b/include/configs/mx31pdk.h
index 5752856..183b0f3 100644
--- a/include/configs/mx31pdk.h
+++ b/include/configs/mx31pdk.h
@@ -38,6 +38,9 @@
#define CONFIG_MX31_HCLK_FREQ 26000000
#define CONFIG_MX31_CLK32 32768

+/* We are booting from NAND. Used to shrink start.S */
+#define CONFIG_BOOT_FROM_NAND 1
+
#define CONFIG_DISPLAY_CPUINFO
#define CONFIG_DISPLAY_BOARDINFO

@@ -45,11 +48,6 @@
#define CONFIG_SETUP_MEMORY_TAGS 1
#define CONFIG_INITRD_TAG 1

-/* No support for NAND boot for i.MX31 PDK yet, so we rely on some other
- * program to initialize the SDRAM.
- */
-#define CONFIG_SKIP_LOWLEVEL_INIT
-
/*
* Size of malloc() pool
*/
@@ -136,6 +134,13 @@
#define CONFIG_CMDLINE_EDITING 1

/*-----------------------------------------------------------------------
+ * Early stack pointer
+ *
+ * Use internal SRAM memory as SP when booting from NAND (ie. to iMX NFC)
+ */
+#define CFG_INTERNAL_SRAM_STACK 0x1FFFFFF0
+
+/*-----------------------------------------------------------------------
* Stack sizes
*
* The stack sizes are set up in start.S using the settings below
--
1.5.4.3