ARM: OMAP: Correct save_boot_params and replace with 'C' function

Currently save_boot_params saves the boot parameters passed
from romcode. But this is not stored in a writable location
consistently. So the current code would not work for a
'XIP' boot. Change this by saving the boot parameters in
'gd' which is always writable. Also add a 'C' function
instead of an assembly code that is more readable.

Signed-off-by: Sricharan R <r.sricharan@ti.com>
diff --git a/arch/arm/cpu/armv7/omap-common/hwinit-common.c b/arch/arm/cpu/armv7/omap-common/hwinit-common.c
index 70d16a8..c710784 100644
--- a/arch/arm/cpu/armv7/omap-common/hwinit-common.c
+++ b/arch/arm/cpu/armv7/omap-common/hwinit-common.c
@@ -101,11 +101,6 @@
 }
 
 #ifdef CONFIG_SPL_BUILD
-static void init_boot_params(void)
-{
-	boot_params_ptr = (u32 *) &boot_params;
-}
-
 void spl_display_print(void)
 {
 	omap_rev_string();
@@ -114,6 +109,42 @@
 
 void __weak srcomp_enable(void)
 {
+}
+
+static void save_omap_boot_params(void)
+{
+	u32 rom_params = *((u32 *)OMAP_SRAM_SCRATCH_BOOT_PARAMS);
+	u8 boot_device;
+	u32 dev_desc, dev_data;
+
+	if ((rom_params <  NON_SECURE_SRAM_START) ||
+	    (rom_params > NON_SECURE_SRAM_END))
+		return;
+
+	/*
+	 * rom_params can be type casted to omap_boot_parameters and
+	 * used. But it not correct to assume that romcode structure
+	 * encoding would be same as u-boot. So use the defined offsets.
+	 */
+	gd->arch.omap_boot_params.omap_bootdevice = boot_device =
+				   *((u8 *)(rom_params + BOOT_DEVICE_OFFSET));
+
+	gd->arch.omap_boot_params.ch_flags =
+				*((u8 *)(rom_params + CH_FLAGS_OFFSET));
+
+	if ((boot_device >= MMC_BOOT_DEVICES_START) &&
+	    (boot_device <= MMC_BOOT_DEVICES_END)) {
+		if ((omap_hw_init_context() ==
+				      OMAP_INIT_CONTEXT_UBOOT_AFTER_SPL)) {
+			gd->arch.omap_boot_params.omap_bootmode =
+			*((u8 *)(rom_params + BOOT_MODE_OFFSET));
+		} else {
+			dev_desc = *((u32 *)(rom_params + DEV_DESC_PTR_OFFSET));
+			dev_data = *((u32 *)(dev_desc + DEV_DATA_PTR_OFFSET));
+			gd->arch.omap_boot_params.omap_bootmode =
+					*((u32 *)(dev_data + BOOT_MODE_OFFSET));
+		}
+	}
 }
 
 /*
@@ -132,6 +163,14 @@
  */
 void s_init(void)
 {
+	/*
+	 * Save the boot parameters passed from romcode.
+	 * We cannot delay the saving further than this,
+	 * to prevent overwrites.
+	 */
+#ifdef CONFIG_SPL_BUILD
+	save_omap_boot_params();
+#endif
 	init_omap_revision();
 	hw_data_init();
 
@@ -156,7 +195,6 @@
 
 	/* For regular u-boot sdram_init() is called from dram_init() */
 	sdram_init();
-	init_boot_params();
 #endif
 }
 
diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index 37ac0da..7611d0a 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -24,6 +24,10 @@
 #ifndef	__ASM_GBL_DATA_H
 #define __ASM_GBL_DATA_H
 
+#ifdef CONFIG_OMAP
+#include <asm/omap_boot.h>
+#endif
+
 /* Architecture-specific global data */
 struct arch_global_data {
 #if defined(CONFIG_FSL_ESDHC)
@@ -51,6 +55,10 @@
 	unsigned long tlb_addr;
 	unsigned long tlb_size;
 #endif
+
+#ifdef CONFIG_OMAP
+	struct omap_boot_parameters omap_boot_params;
+#endif
 };
 
 #include <asm-generic/global_data.h>
diff --git a/arch/arm/include/asm/omap_boot.h b/arch/arm/include/asm/omap_boot.h
index 87a9530..a803965 100644
--- a/arch/arm/include/asm/omap_boot.h
+++ b/arch/arm/include/asm/omap_boot.h
@@ -45,5 +45,6 @@
 	unsigned char omap_bootdevice;
 	unsigned char reset_reason;
 	unsigned char ch_flags;
+	unsigned long omap_bootmode;
 };
 #endif
diff --git a/arch/arm/include/asm/omap_common.h b/arch/arm/include/asm/omap_common.h
index 837b69f..eebc9c7 100644
--- a/arch/arm/include/asm/omap_common.h
+++ b/arch/arm/include/asm/omap_common.h
@@ -597,5 +597,7 @@
 #define OMAP_SRAM_SCRATCH_DPLLS_PTR     (SRAM_SCRATCH_SPACE_ADDR + 0x18)
 #define OMAP_SRAM_SCRATCH_VCORES_PTR    (SRAM_SCRATCH_SPACE_ADDR + 0x1C)
 #define OMAP_SRAM_SCRATCH_SYS_CTRL	(SRAM_SCRATCH_SPACE_ADDR + 0x20)
-#define OMAP_SRAM_SCRATCH_SPACE_END	(SRAM_SCRATCH_SPACE_ADDR + 0x24)
+#define OMAP_SRAM_SCRATCH_BOOT_PARAMS	(SRAM_SCRATCH_SPACE_ADDR + 0x24)
+#define OMAP5_SRAM_SCRATCH_SPACE_END	(SRAM_SCRATCH_SPACE_ADDR + 0x28)
+
 #endif /* _OMAP_COMMON_H_ */