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>

9 files changed, 201 insertions, 2 deletions

diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile
index 299792ac5a..92a5a96800 100644
--- a/arch/arm/cpu/armv7/Makefile
+++ b/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)
diff --git a/arch/arm/cpu/armv7/omap-common/Makefile b/arch/arm/cpu/armv7/omap-common/Makefile
index 8f698f841d..07087964e6 100644
--- a/arch/arm/cpu/armv7/omap-common/Makefile
+++ b/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))
 
diff --git a/arch/arm/cpu/armv7/omap-common/spl.c b/arch/arm/cpu/armv7/omap-common/spl.c
new file mode 100644
index 0000000000..b2015431e3
--- /dev/null
+++ b/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);
+}
diff --git a/arch/arm/cpu/armv7/omap-common/u-boot-spl.lds b/arch/arm/cpu/armv7/omap-common/u-boot-spl.lds
new file mode 100644
index 0000000000..8867e0604d
--- /dev/null
+++ b/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
+}
diff --git a/arch/arm/cpu/armv7/omap4/Makefile b/arch/arm/cpu/armv7/omap4/Makefile
index e1ccd68192..e7ee0b8c0a 100644
--- a/arch/arm/cpu/armv7/omap4/Makefile
+++ b/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))
diff --git a/arch/arm/cpu/armv7/omap4/board.c b/arch/arm/cpu/armv7/omap4/board.c
index 786c239794..54dd509194 100644
--- a/arch/arm/cpu/armv7/omap4/board.c
+++ b/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
 }
 
 /*
diff --git a/arch/arm/cpu/armv7/omap4/clocks.c b/arch/arm/cpu/armv7/omap4/clocks.c
index e8d3a52440..f1e233a10e 100644
--- a/arch/arm/cpu/armv7/omap4/clocks.c
+++ b/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()) {
diff --git a/arch/arm/include/asm/arch-omap4/sys_proto.h b/arch/arm/include/asm/arch-omap4/sys_proto.h
index 1e62878ea4..a81f8e5c24 100644
--- a/arch/arm/include/asm/arch-omap4/sys_proto.h
+++ b/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);
diff --git a/arch/arm/include/asm/omap_common.h b/arch/arm/include/asm/omap_common.h
index 33caa4e6cc..69d53d2c72 100644
--- a/arch/arm/include/asm/omap_common.h
+++ b/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_ */