omap: add basic SPL support

- Provide alternate implementations of board_init_f()
  board_init_r() for OMAP spl.
- Provide linker script
- Initialize global data
- Add serial console support
- Update CONFIG_SYS_TEXT_BASE to allow for SPL's bss and move
  it to board config header from config.mk

Signed-off-by: Aneesh V <aneesh@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

arch/arm/cpu/armv7/Makefile

@@ -26,7 +26,12 @@ include $(TOPDIR)/config.mk
 LIB	= $(obj)lib$(CPU).o
 
 START	:= start.o
-COBJS	:= cpu.o cache_v7.o
+
+ifndef CONFIG_SPL_BUILD
+COBJS	+= cache_v7.o
+COBJS	+= cpu.o
+endif
+
 COBJS  += syslib.o
 
 SRCS	:= $(START:.o=.S) $(COBJS:.o=.c)

arch/arm/cpu/armv7/omap-common/Makefile

@@ -30,6 +30,10 @@ SOBJS	:= reset.o
 COBJS	:= timer.o
 COBJS	+= utils.o
 
+ifdef CONFIG_SPL_BUILD
+COBJS	+= spl.o
+endif
+
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
 

arch/arm/cpu/armv7/omap-common/spl.c

@@ -0,0 +1,82 @@
+/*
+ * (C) Copyright 2010
+ * Texas Instruments, <www.ti.com>
+ *
+ * Aneesh V <aneesh@ti.com>
+ *
+ * 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
+ */
+#include <common.h>
+#include <asm/u-boot.h>
+#include <asm/arch/sys_proto.h>
+#include <timestamp_autogenerated.h>
+#include <version_autogenerated.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Define global data structure pointer to it*/
+static gd_t gdata __attribute__ ((section(".data")));
+static bd_t bdata __attribute__ ((section(".data")));
+
+inline void hang(void)
+{
+	puts("### ERROR ### Please RESET the board ###\n");
+	for (;;)
+		;
+}
+
+void board_init_f(ulong dummy)
+{
+	/*
+	 * We call relocate_code() with relocation target same as the
+	 * CONFIG_SYS_SPL_TEXT_BASE. This will result in relocation getting
+	 * skipped. Instead, only .bss initialization will happen. That's
+	 * all we need
+	 */
+	debug(">>board_init_f()\n");
+	relocate_code(CONFIG_SPL_STACK, &gdata, CONFIG_SPL_TEXT_BASE);
+}
+
+void board_init_r(gd_t *id, ulong dummy)
+{
+	for (;;)
+		;
+}
+
+void preloader_console_init(void)
+{
+	const char *u_boot_rev = U_BOOT_VERSION;
+	char rev_string_buffer[50];
+
+	gd = &gdata;
+	gd->bd = &bdata;
+	gd->flags |= GD_FLG_RELOC;
+	gd->baudrate = CONFIG_BAUDRATE;
+
+	setup_clocks_for_console();
+	serial_init();		/* serial communications setup */
+
+	/* Avoid a second "U-Boot" coming from this string */
+	u_boot_rev = &u_boot_rev[7];
+
+	printf("\nU-Boot SPL %s (%s - %s)\n", u_boot_rev, U_BOOT_DATE,
+		U_BOOT_TIME);
+	omap_rev_string(rev_string_buffer);
+	printf("Texas Instruments %s\n", rev_string_buffer);
+}

arch/arm/cpu/armv7/omap-common/u-boot-spl.lds

@@ -0,0 +1,62 @@
+/*
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
+ *
+ * (C) Copyright 2010
+ * Texas Instruments, <www.ti.com>
+ *	Aneesh V <aneesh@ti.com>
+ *
+ * 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
+ */
+
+MEMORY { .sram : ORIGIN = CONFIG_SPL_TEXT_BASE,\
+		LENGTH = CONFIG_SPL_MAX_SIZE }
+MEMORY { .sdram : ORIGIN = CONFIG_SPL_BSS_START_ADDR, \
+		LENGTH = CONFIG_SPL_BSS_MAX_SIZE }
+
+OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
+OUTPUT_ARCH(arm)
+ENTRY(_start)
+SECTIONS
+{
+	.text      :
+	{
+	__start = .;
+	  arch/arm/cpu/armv7/start.o	(.text)
+	  *(.text*)
+	} >.sram
+
+	. = ALIGN(4);
+	.rodata : { *(SORT_BY_ALIGNMENT(.rodata*)) } >.sram
+
+	. = ALIGN(4);
+	.data : { *(SORT_BY_ALIGNMENT(.data*)) } >.sram
+	. = ALIGN(4);
+	__image_copy_end = .;
+	_end = .;
+
+	.bss :
+	{
+		. = ALIGN(4);
+		__bss_start = .;
+		*(.bss*)
+		. = ALIGN(4);
+		__bss_end__ = .;
+	} >.sdram
+}

arch/arm/cpu/armv7/omap4/Makefile

@@ -30,9 +30,12 @@ SOBJS	+= lowlevel_init.o
 COBJS	+= board.o
 COBJS	+= clocks.o
 COBJS	+= emif.o
-COBJS	+= mem.o
 COBJS	+= sdram_elpida.o
+
+ifndef CONFIG_SPL_BUILD
+COBJS	+= mem.o
 COBJS	+= sys_info.o
+endif
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS) $(SOBJS))

arch/arm/cpu/armv7/omap4/board.c

@@ -155,7 +155,14 @@ void s_init(void)
 	init_omap4_revision();
 	watchdog_init();
 	set_mux_conf_regs();
+#ifdef CONFIG_SPL_BUILD
+	preloader_console_init();
+#endif
 	prcm_init();
+#ifdef CONFIG_SPL_BUILD
+	/* For regular u-boot sdram_init() is called from dram_init() */
+	sdram_init();
+#endif
 }
 
 /*

arch/arm/cpu/armv7/omap4/clocks.c

@@ -791,6 +791,39 @@ void lock_dpll(u32 *const base)
 	wait_for_lock(base);
 }
 
+void setup_clocks_for_console(void)
+{
+	/* Do not add any spl_debug prints in this function */
+	clrsetbits_le32(&prcm->cm_l4per_clkstctrl, CD_CLKCTRL_CLKTRCTRL_MASK,
+			CD_CLKCTRL_CLKTRCTRL_SW_WKUP <<
+			CD_CLKCTRL_CLKTRCTRL_SHIFT);
+
+	/* Enable all UARTs - console will be on one of them */
+	clrsetbits_le32(&prcm->cm_l4per_uart1_clkctrl,
+			MODULE_CLKCTRL_MODULEMODE_MASK,
+			MODULE_CLKCTRL_MODULEMODE_SW_EXPLICIT_EN <<
+			MODULE_CLKCTRL_MODULEMODE_SHIFT);
+
+	clrsetbits_le32(&prcm->cm_l4per_uart2_clkctrl,
+			MODULE_CLKCTRL_MODULEMODE_MASK,
+			MODULE_CLKCTRL_MODULEMODE_SW_EXPLICIT_EN <<
+			MODULE_CLKCTRL_MODULEMODE_SHIFT);
+
+	clrsetbits_le32(&prcm->cm_l4per_uart3_clkctrl,
+			MODULE_CLKCTRL_MODULEMODE_MASK,
+			MODULE_CLKCTRL_MODULEMODE_SW_EXPLICIT_EN <<
+			MODULE_CLKCTRL_MODULEMODE_SHIFT);
+
+	clrsetbits_le32(&prcm->cm_l4per_uart3_clkctrl,
+			MODULE_CLKCTRL_MODULEMODE_MASK,
+			MODULE_CLKCTRL_MODULEMODE_SW_EXPLICIT_EN <<
+			MODULE_CLKCTRL_MODULEMODE_SHIFT);
+
+	clrsetbits_le32(&prcm->cm_l4per_clkstctrl, CD_CLKCTRL_CLKTRCTRL_MASK,
+			CD_CLKCTRL_CLKTRCTRL_HW_AUTO <<
+			CD_CLKCTRL_CLKTRCTRL_SHIFT);
+}
+
 void prcm_init(void)
 {
 	switch (omap4_hw_init_context()) {

arch/arm/include/asm/arch-omap4/sys_proto.h

@@ -44,6 +44,7 @@ u32 wait_on_value(u32, u32, void *, u32);
 void sdelay(unsigned long);
 void set_pl310_ctrl_reg(u32 val);
 void omap_rev_string(char *omap4_rev_string);
+void setup_clocks_for_console(void);
 void prcm_init(void);
 void bypass_dpll(u32 *const base);
 void freq_update_core(void);

arch/arm/include/asm/omap_common.h

@@ -34,4 +34,6 @@
 #define OMAP_INIT_CONTEXT_UBOOT_AFTER_SPL	2
 #define OMAP_INIT_CONTEXT_UBOOT_AFTER_CH	3
 
+void preloader_console_init(void);
+
 #endif /* _OMAP_COMMON_H_ */

board/ti/panda/Makefile

@@ -25,7 +25,9 @@ include $(TOPDIR)/config.mk
 
 LIB	= $(obj)lib$(BOARD).o
 
+ifndef CONFIG_SPL_BUILD
 COBJS	:= panda.o
+endif
 
 SRCS	:= $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))

board/ti/panda/config.mk

@@ -1,31 +0,0 @@
-#
-# (C) Copyright 2006-2009
-# Texas Instruments Incorporated, <www.ti.com>
-#
-# OMAP 4430 SDP
-# see http://www.ti.com/ for more information on Texas Instruments
-#
-# 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
-#
-# SDRAM Address Space:
-# 8000'0000 - 9fff'ffff (512 MB)
-# Linux-Kernel is expected to be at 8000'8000, entry 8000'8000
-# (mem base + reserved)
-
-CONFIG_SYS_TEXT_BASE = 0x80e80000

board/ti/sdp4430/Makefile

@@ -25,7 +25,9 @@ include $(TOPDIR)/config.mk
 
 LIB	= $(obj)lib$(BOARD).o
 
+ifndef CONFIG_SPL_BUILD
 COBJS	:= sdp.o cmd_bat.o
+endif
 
 SRCS	:= $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))

board/ti/sdp4430/config.mk

@@ -1,31 +0,0 @@
-#
-# (C) Copyright 2006-2009
-# Texas Instruments Incorporated, <www.ti.com>
-#
-# OMAP 4430 SDP
-# see http://www.ti.com/ for more information on Texas Instruments
-#
-# 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
-#
-# SDRAM Address Space:
-# 8000'0000 - 9fff'ffff (512 MB)
-# Linux-Kernel is expected to be at 8000'8000, entry 8000'8000
-# (mem base + reserved)
-
-CONFIG_SYS_TEXT_BASE = 0x80e80000

include/configs/omap4_panda.h

@@ -243,4 +243,30 @@
 #define CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS
 #endif
 
+/* Defines for SPL */
+#define CONFIG_SPL
+#define CONFIG_SPL_TEXT_BASE		0x40304350
+#define CONFIG_SPL_MAX_SIZE		0x8000	/* 32 K */
+#define CONFIG_SPL_STACK		LOW_LEVEL_SRAM_STACK
+
+#define CONFIG_SPL_BSS_START_ADDR	0x80000000
+#define CONFIG_SPL_BSS_MAX_SIZE		0x80000		/* 512 KB */
+
+#define CONFIG_SPL_LIBCOMMON_SUPPORT
+#define CONFIG_SPL_LIBDISK_SUPPORT
+#define CONFIG_SPL_I2C_SUPPORT
+#define CONFIG_SPL_MMC_SUPPORT
+#define CONFIG_SPL_FAT_SUPPORT
+#define CONFIG_SPL_LIBGENERIC_SUPPORT
+#define CONFIG_SPL_SERIAL_SUPPORT
+#define CONFIG_SPL_LDSCRIPT "arch/arm/cpu/armv7/omap-common/u-boot-spl.lds"
+
+/*
+ * 1MB into the SDRAM to allow for SPL's bss at the beginning of SDRAM
+ * 64 bytes before this address should be set aside for u-boot.img's
+ * header. That is 0x800FFFC0--0x80100000 should not be used for any
+ * other needs.
+ */
+#define CONFIG_SYS_TEXT_BASE		0x80100000
+
 #endif /* __CONFIG_H */

include/configs/omap4_sdp4430.h

@@ -249,4 +249,30 @@
 #define CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS
 #endif
 
+/* Defines for SPL */
+#define CONFIG_SPL
+#define CONFIG_SPL_TEXT_BASE		0x40304350
+#define CONFIG_SPL_MAX_SIZE		0x8000	/* 32 K */
+#define CONFIG_SPL_STACK		LOW_LEVEL_SRAM_STACK
+
+#define CONFIG_SPL_BSS_START_ADDR	0x80000000
+#define CONFIG_SPL_BSS_MAX_SIZE		0x80000		/* 512 KB */
+
+#define CONFIG_SPL_LIBCOMMON_SUPPORT
+#define CONFIG_SPL_LIBDISK_SUPPORT
+#define CONFIG_SPL_I2C_SUPPORT
+#define CONFIG_SPL_MMC_SUPPORT
+#define CONFIG_SPL_FAT_SUPPORT
+#define CONFIG_SPL_LIBGENERIC_SUPPORT
+#define CONFIG_SPL_SERIAL_SUPPORT
+#define CONFIG_SPL_LDSCRIPT "arch/arm/cpu/armv7/omap-common/u-boot-spl.lds"
+
+/*
+ * 1MB into the SDRAM to allow for SPL's bss at the beginning of SDRAM
+ * 64 bytes before this address should be set aside for u-boot.img's
+ * header. That is 0x800FFFC0--0x80100000 should not be used for any
+ * other needs.
+ */
+#define CONFIG_SYS_TEXT_BASE		0x80100000
+
 #endif /* __CONFIG_H */