Updated comments and README

4 files changed, 103 insertions, 8 deletions

diff --git a/nuttx/arch/arm/src/armv7-a/arm_mmu.c b/nuttx/arch/arm/src/armv7-a/arm_mmu.c
index f82490caf..0e417af64 100644
--- a/nuttx/arch/arm/src/armv7-a/arm_mmu.c
+++ b/nuttx/arch/arm/src/armv7-a/arm_mmu.c
@@ -194,7 +194,7 @@ void mmu_invalidate_region(uint32_t vstart, size_t size)
   uint32_t vaddr = vstart & 0xfffff000;
   uint32_t vend  = vaddr + size;
 
-  /* Loop, writing each mapping into the L1 page table */
+  /* Loop, invalidating regions */
 
   while (vaddr < vend)
     {
diff --git a/nuttx/configs/sama5d3-xplained/README.txt b/nuttx/configs/sama5d3-xplained/README.txt
index e5f19ebb5..c763db405 100644
--- a/nuttx/configs/sama5d3-xplained/README.txt
+++ b/nuttx/configs/sama5d3-xplained/README.txt
@@ -5,7 +5,7 @@ README
   development board. This board features the Atmel SAMA5D36 microprocessor.
   See http://www.atmel.com/devices/sama5d36.aspx for further information.
 
-    PARAMTER                  SAMA5D36
+    PARAMETER                 SAMA5D36
     ------------------------- -------------
     Pin Count                 324
     Max. Operating Frequency  536 MHz
@@ -526,7 +526,52 @@ Load NuttX with U-Boot on AT91 boards
       -n nuttx: Set image name.
       -d nuttx.bin: Use image data from nuttx.bin.
 
-    This will generate a binary called uImage.
+    This will generate a binary called uImage.  If you have the path to
+    mkimage in your PATH variable, then you can automatically build the
+    uImage file by adding the following to your .config file:
+
+      CONFIG_RAW_BINARY=y
+      CONFIG_UBOOT_UIMAGE=y
+      CONFIG_UIMAGE_LOAD_ADDRESS=0x20008000
+      CONFIG_UIMAGE_ENTRY_POINT=0x20008040
+
+    The uImage file can them be loaded into memory from a variety of sources
+    (serial, SD card, JFFS2 on NAND, TFTP).
+
+    STATUS:
+      2014-4-1:  So far, I am unable to get U-Boot to execute the uImage
+                 file.  I get the following error messages (in this case
+                 trying to load from an SD card):
+
+        U-Boot> fatload mmc 0 0x22000000 uimage
+        reading uimage
+        97744 bytes read in 21 ms (4.4 MiB/s)
+        U-Boot> bootm 0x22000000
+        ## Booting kernel from Legacy Image at 0x22000000 ...
+           Image Name:   nuttx
+           Image Type:   ARM Linux Kernel Image (uncompressed)
+           Data Size:    97680 Bytes = 95.4 KiB
+           Load Address: 20008000
+           Entry Point:  20008040
+           Verifying Checksum ... OK
+           XIP Kernel Image ... OK
+        FDT and ATAGS support not compiled in - hanging
+        ### ERROR ### Please RESET the board ###
+
+      This, however, appears to be a usable workaround:
+
+      U-Boot> fatload mmc 0 0x20008000 nuttx.bin
+      mci: setting clock 257812 Hz, block size 512
+      mci: setting clock 257812 Hz, block size 512
+      mci: setting clock 257812 Hz, block size 512
+      gen_atmel_mci: CMDR 00001048 ( 8) ARGR 000001aa (SR: 0c100025) Command Time Out
+      mci: setting clock 257812 Hz, block size 512
+      mci: setting clock 22000000 Hz, block size 512
+      reading nuttx.bin
+      108076 bytes read in 23 ms (4.5 MiB/s)
+      U-Boot> go 0x20008040
+      ## Starting application at 0x20008040 ...
+      os_start: Entry
 
   Loading through network
 
@@ -2623,9 +2668,15 @@ Configurations
        for further information.
 
     3. This configuration executes out of SDRAM flash and is loaded into
-       SDRAM from NAND, Serial DataFlash, or from a TFTPC sever via
+       SDRAM from NAND, Serial DataFlash, SD card or from a TFTPC sever via
        U-Boot or BareBox.  Data also is positioned in SDRAM.
 
+       I did most testing with nuttx.bin on an SD card.  These are the
+       commands that I used to boot NuttX from the SD card:
+
+         U-Boot> fatload mmc 0 0x20008000 nuttx.bin
+         U-Boot> go 0x20008040
+
     4. This configuration has support for NSH built-in applications enabled.
        However, no built-in applications are selected in the base configuration.
 
diff --git a/nuttx/configs/sama5d3-xplained/nsh/defconfig b/nuttx/configs/sama5d3-xplained/nsh/defconfig
index 0ead1922a..05365a61e 100644
--- a/nuttx/configs/sama5d3-xplained/nsh/defconfig
+++ b/nuttx/configs/sama5d3-xplained/nsh/defconfig
@@ -30,9 +30,7 @@ CONFIG_WINDOWS_CYGWIN=y
 CONFIG_INTELHEX_BINARY=y
 # CONFIG_MOTOROLA_SREC is not set
 CONFIG_RAW_BINARY=y
-CONFIG_UBOOT_UIMAGE=y
-CONFIG_UIMAGE_LOAD_ADDRESS=0x20008000
-CONFIG_UIMAGE_ENTRY_POINT=0x20008000
+# CONFIG_UBOOT_UIMAGE is not set
 
 #
 # Customize Header Files
@@ -191,6 +189,7 @@ CONFIG_SAMA5_HSMC=y
 CONFIG_SAMA5_DBGU_CONSOLE=y
 CONFIG_SAMA5_DBGU_RXBUFSIZE=256
 CONFIG_SAMA5_DBGU_TXBUFSIZE=256
+# CONFIG_SAMA5_DBGU_NOCONFIG is not set
 CONFIG_SAMA5_DBGU_BAUD=115200
 CONFIG_SAMA5_DBGU_PARITY=0
 
diff --git a/nuttx/configs/sama5d3x-ek/README.txt b/nuttx/configs/sama5d3x-ek/README.txt
index 728356110..d26fc292f 100644
--- a/nuttx/configs/sama5d3x-ek/README.txt
+++ b/nuttx/configs/sama5d3x-ek/README.txt
@@ -647,7 +647,52 @@ Load NuttX with U-Boot on AT91 boards
       -n nuttx: Set image name.
       -d nuttx.bin: Use image data from nuttx.bin.
 
-    This will generate a binary called uImage.
+    This will generate a binary called uImage.  If you have the path to
+    mkimage in your PATH variable, then you can automatically build the
+    uImage file by adding the following to your .config file:
+
+      CONFIG_RAW_BINARY=y
+      CONFIG_UBOOT_UIMAGE=y
+      CONFIG_UIMAGE_LOAD_ADDRESS=0x20008000
+      CONFIG_UIMAGE_ENTRY_POINT=0x20008040
+
+    The uImage file can them be loaded into memory from a variety of sources
+    (serial, SD card, JFFS2 on NAND, TFTP).
+
+    STATUS:
+      2014-4-1:  So far, I am unable to get U-Boot to execute the uImage
+                 file.  I get the following error messages (in this case
+                 trying to load from an SD card):
+
+        U-Boot> fatload mmc 0 0x22000000 uimage
+        reading uimage
+        97744 bytes read in 21 ms (4.4 MiB/s)
+        U-Boot> bootm 0x22000000
+        ## Booting kernel from Legacy Image at 0x22000000 ...
+           Image Name:   nuttx
+           Image Type:   ARM Linux Kernel Image (uncompressed)
+           Data Size:    97680 Bytes = 95.4 KiB
+           Load Address: 20008000
+           Entry Point:  20008040
+           Verifying Checksum ... OK
+           XIP Kernel Image ... OK
+        FDT and ATAGS support not compiled in - hanging
+        ### ERROR ### Please RESET the board ###
+
+      This, however, appears to be a usable workaround:
+
+      U-Boot> fatload mmc 0 0x20008000 nuttx.bin
+      mci: setting clock 257812 Hz, block size 512
+      mci: setting clock 257812 Hz, block size 512
+      mci: setting clock 257812 Hz, block size 512
+      gen_atmel_mci: CMDR 00001048 ( 8) ARGR 000001aa (SR: 0c100025) Command Time Out
+      mci: setting clock 257812 Hz, block size 512
+      mci: setting clock 22000000 Hz, block size 512
+      reading nuttx.bin
+      108076 bytes read in 23 ms (4.5 MiB/s)
+      U-Boot> go 0x20008040
+      ## Starting application at 0x20008040 ...
+      os_start: Entry
 
   Loading through network