am335x_evm: Add support to boot from NOR.

NOR requires that s_init be within the first 4KiB of the image so that
we can perform the rest of the required pinmuxing to talk with the rest
of NOR that we are found on.  When NOR_BOOT is set we save our
environment in NOR at 512KiB and a redundant copy at 768KiB.  We avoid
using SPL for this case and u-boot.bin is written directly to the start
of NOR.

We enclose the DMM-related parts of arch/arm/cpu/armv7/am33xx/emif4.c
with TI81xx checks as at this time U-Boot does not discard unused
sections in the main build and this code relies on functions specific to
(and only provided in) ti81xx-related code.

Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Steve Kipisz <s-kipisz2@ti.com>
Signed-off-by: Tom Rini <trini@ti.com>

4 files changed, 151 insertions, 7 deletions

diff --git a/board/ti/am335x/Makefile b/board/ti/am335x/Makefile
index cb2b999..3dbeeda 100644
--- a/board/ti/am335x/Makefile
+++ b/board/ti/am335x/Makefile
@@ -10,7 +10,7 @@ include $(TOPDIR)/config.mk
 
 LIB	= $(obj)lib$(BOARD).o
 
-ifdef CONFIG_SPL_BUILD
+ifeq ($(CONFIG_SPL_BUILD)$(CONFIG_NOR_BOOT),y)
 COBJS	:= mux.o
 endif
 
diff --git a/board/ti/am335x/board.c b/board/ti/am335x/board.c
index b12341d..728afc2 100644
--- a/board/ti/am335x/board.c
+++ b/board/ti/am335x/board.c
@@ -83,7 +83,7 @@ static int read_eeprom(struct am335x_baseboard_id *header)
 	return 0;
 }
 
-#ifdef CONFIG_SPL_BUILD
+#if defined(CONFIG_SPL_BUILD) || defined(CONFIG_NOR_BOOT)
 static const struct ddr_data ddr2_data = {
 	.datardsratio0 = ((MT47H128M16RT25E_RD_DQS<<30) |
 			  (MT47H128M16RT25E_RD_DQS<<20) |
@@ -249,10 +249,28 @@ int spl_start_uboot(void)
  */
 void s_init(void)
 {
-#ifdef CONFIG_SPL_BUILD
-	struct am335x_baseboard_id header;
+	__maybe_unused struct am335x_baseboard_id header;
 
 	/*
+	 * The ROM will only have set up sufficient pinmux to allow for the
+	 * first 4KiB NOR to be read, we must finish doing what we know of
+	 * the NOR mux in this space in order to continue.
+	 */
+#ifdef CONFIG_NOR_BOOT
+	asm("stmfd      sp!, {r2 - r4}");
+	asm("movw       r4, #0x8A4");
+	asm("movw       r3, #0x44E1");
+	asm("orr        r4, r4, r3, lsl #16");
+	asm("mov        r2, #9");
+	asm("mov        r3, #8");
+	asm("gpmc_mux:  str     r2, [r4], #4");
+	asm("subs       r3, r3, #1");
+	asm("bne        gpmc_mux");
+	asm("ldmfd      sp!, {r2 - r4}");
+#endif
+
+#ifdef CONFIG_SPL_BUILD
+	/*
 	 * Save the boot parameters passed from romcode.
 	 * We cannot delay the saving further than this,
 	 * to prevent overwrites.
@@ -270,7 +288,7 @@ void s_init(void)
 	while (readl(&wdtimer->wdtwwps) != 0x0)
 		;
 
-#ifdef CONFIG_SPL_BUILD
+#if defined(CONFIG_SPL_BUILD) || defined(CONFIG_NOR_BOOT)
 	/* Setup the PLLs and the clocks for the peripherals */
 	pll_init();
 
@@ -298,9 +316,16 @@ void s_init(void)
 
 	uart_soft_reset();
 
+#if defined(CONFIG_NOR_BOOT)
+	/* We want our console now. */
+	gd->baudrate = CONFIG_BAUDRATE;
+	serial_init();
+	gd->have_console = 1;
+#else
 	gd = &gdata;
 
 	preloader_console_init();
+#endif
 
 	/* Initalize the board header */
 	enable_i2c0_pin_mux();
diff --git a/board/ti/am335x/mux.c b/board/ti/am335x/mux.c
index 187468e..5b7ed63 100644
--- a/board/ti/am335x/mux.c
+++ b/board/ti/am335x/mux.c
@@ -190,7 +190,7 @@ static struct module_pin_mux nand_pin_mux[] = {
 	{-1},
 };
 
-#if defined(CONFIG_NOR)
+#if defined(CONFIG_NOR) && !defined(CONFIG_NOR_BOOT)
 static struct module_pin_mux bone_norcape_pin_mux[] = {
 	{OFFSET(lcd_data0), MODE(1) | PULLUDEN | RXACTIVE},     /* NOR_A0 */
 	{OFFSET(lcd_data1), MODE(1) | PULLUDEN | RXACTIVE},     /* NOR_A1 */
@@ -317,8 +317,10 @@ void enable_board_pin_mux(struct am335x_baseboard_id *header)
 		configure_module_pin_mux(i2c1_pin_mux);
 		configure_module_pin_mux(mii1_pin_mux);
 		configure_module_pin_mux(mmc0_pin_mux);
+#ifndef CONFIG_NOR
 		configure_module_pin_mux(mmc1_pin_mux);
-#if defined(CONFIG_NOR)
+#endif
+#if defined(CONFIG_NOR) && !defined(CONFIG_NOR_BOOT)
 		configure_module_pin_mux(bone_norcape_pin_mux);
 #endif
 	} else if (board_is_gp_evm(header)) {
diff --git a/board/ti/am335x/u-boot.lds b/board/ti/am335x/u-boot.lds
new file mode 100644
index 0000000..a173f62
--- /dev/null
+++ b/board/ti/am335x/u-boot.lds
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2004-2008 Texas Instruments
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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
+ */
+
+OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
+OUTPUT_ARCH(arm)
+ENTRY(_start)
+SECTIONS
+{
+	. = 0x00000000;
+
+	. = ALIGN(4);
+	.text :
+	{
+		*(.__image_copy_start)
+		CPUDIR/start.o (.text*)
+		board/ti/am335x/libam335x.o (.text*)
+		*(.text*)
+	}
+
+	. = ALIGN(4);
+	.rodata : { *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*))) }
+
+	. = ALIGN(4);
+	.data : {
+		*(.data*)
+	}
+
+	. = ALIGN(4);
+
+	. = .;
+
+	. = ALIGN(4);
+	.u_boot_list : {
+		KEEP(*(SORT(.u_boot_list*)));
+	}
+
+	. = ALIGN(4);
+
+	.image_copy_end :
+	{
+		*(.__image_copy_end)
+	}
+
+	.rel_dyn_start :
+	{
+		*(.__rel_dyn_start)
+	}
+
+	.rel.dyn : {
+		*(.rel*)
+	}
+
+	.rel_dyn_end :
+	{
+		*(.__rel_dyn_end)
+	}
+
+	_end = .;
+
+	/*
+	 * Deprecated: this MMU section is used by pxa at present but
+	 * should not be used by new boards/CPUs.
+	 */
+	. = ALIGN(4096);
+	.mmutable : {
+		*(.mmutable)
+	}
+
+/*
+ * Compiler-generated __bss_start and __bss_end, see arch/arm/lib/bss.c
+ * __bss_base and __bss_limit are for linker only (overlay ordering)
+ */
+
+	.bss_start __rel_dyn_start (OVERLAY) : {
+		KEEP(*(.__bss_start));
+		__bss_base = .;
+	}
+
+	.bss __bss_base (OVERLAY) : {
+		*(.bss*)
+		 . = ALIGN(4);
+		 __bss_limit = .;
+	}
+
+	.bss_end __bss_limit (OVERLAY) : {
+		KEEP(*(.__bss_end));
+	}
+
+	/DISCARD/ : { *(.dynsym) }
+	/DISCARD/ : { *(.dynstr*) }
+	/DISCARD/ : { *(.dynamic*) }
+	/DISCARD/ : { *(.plt*) }
+	/DISCARD/ : { *(.interp*) }
+	/DISCARD/ : { *(.gnu*) }
+}