TI: Add, use a DEFAULT_LINUX_BOOT_ENV environment string

To deal with a reoccurring problem properly we need to specify addresses
for the Linux kernel, Flatted Device Tree and ramdisk that obey the
constraints within the kernel's Documentation/arm/Booting file but also
make sure that we relocate things within a valid address range.

It is possible with these addresses to also set fdt_high and initrd_high
to the value of 0xffffffff.  We don't do this by default to allow for
the most likely success of people using custom addresses however.

Signed-off-by: Tom Rini <trini@ti.com>

include/configs/am335x_evm.h

@@ -61,11 +61,8 @@
 
 #ifndef CONFIG_SPL_BUILD
 #define CONFIG_EXTRA_ENV_SETTINGS \
-	"loadaddr=0x80200000\0" \
+	DEFAULT_LINUX_BOOT_ENV \
-	"fdtaddr=0x80F80000\0" \
-	"fdt_high=0xffffffff\0" \
 	"boot_fdt=try\0" \
-	"rdaddr=0x81000000\0" \
 	"bootpart=0:2\0" \
 	"bootdir=/boot\0" \
 	"bootfile=zImage\0" \

include/configs/am43xx_evm.h

@@ -112,10 +112,7 @@
 
 #ifndef CONFIG_SPL_BUILD
 #define CONFIG_EXTRA_ENV_SETTINGS \
-	"loadaddr=0x80200000\0" \
+	DEFAULT_LINUX_BOOT_ENV \
-	"fdtaddr=0x80F80000\0" \
-	"fdt_high=0xffffffff\0" \
-	"rdaddr=0x81000000\0" \
 	"fdtfile=undefined\0" \
 	"bootpart=0:2\0" \
 	"bootdir=/boot\0" \

include/configs/ti_armv7_common.h

@@ -36,8 +36,28 @@
 /*
  * Our DDR memory always starts at 0x80000000 and U-Boot shall have
  * relocated itself to higher in memory by the time this value is used.
+ * However, set this to a 32MB offset to allow for easier Linux kernel
+ * booting as the default is often used as the kernel load address.
  */
-#define CONFIG_SYS_LOAD_ADDR		0x80000000
+#define CONFIG_SYS_LOAD_ADDR		0x82000000
+
+/*
+ * We setup defaults based on constraints from the Linux kernel, which should
+ * also be safe elsewhere.  We have the default load at 32MB into DDR (for
+ * the kernel), FDT above 128MB (the maximum location for the end of the
+ * kernel), and the ramdisk 512KB above that (allowing for hopefully never
+ * seen large trees).  We say all of this must be within the first 256MB
+ * as that will normally be within the kernel lowmem and thus visible via
+ * bootm_size and we only run on platforms with 256MB or more of memory.
+ */
+#define DEFAULT_LINUX_BOOT_ENV \
+	"loadaddr=0x82000000\0" \
+	"kernel_addr_r=0x82000000\0" \
+	"fdtaddr=0x88000000\0" \
+	"fdt_addr_r=0x88000000\0" \
+	"rdaddr=0x88080000\0" \
+	"ramdisk_addr_r=0x88080000\0" \
+	"bootm_size=0x10000000\0"
 
 /*
  * Default to a quick boot delay.

include/configs/ti_omap4_common.h

@@ -87,10 +87,8 @@
  * Environment setup
  */
 #define CONFIG_EXTRA_ENV_SETTINGS \
-	"loadaddr=0x82000000\0" \
+	DEFAULT_LINUX_BOOT_ENV \
 	"console=ttyO2,115200n8\0" \
-	"fdt_high=0xffffffff\0" \
-	"fdtaddr=0x80f80000\0" \
 	"fdtfile=undefined\0" \
 	"bootpart=0:2\0" \
 	"bootdir=/boot\0" \

include/configs/ti_omap5_common.h

@@ -70,10 +70,7 @@
 #endif
 
 #define CONFIG_EXTRA_ENV_SETTINGS \
-	"loadaddr=0x80200000\0" \
+	DEFAULT_LINUX_BOOT_ENV \
-	"fdtaddr=0x80F80000\0" \
-	"fdt_high=0xffffffff\0" \
-	"rdaddr=0x81000000\0" \
 	"console=" CONSOLEDEV ",115200n8\0" \
 	"fdtfile=undefined\0" \
 	"bootpart=0:2\0" \