at91: Defined main clock frequency on esd at91 boards

[karo-tx-uboot.git] / README

diff --git a/README b/README
index cdd81d4efe3efafd8e8e3653303eec1af2e599f5..ccaace797f125f6b971451f5797684a510e44db3 100644 (file)
--- a/README
+++ b/README
@@ -143,9 +143,9 @@ Directory Hierarchy:
     /cpu               CPU specific files
       /arm720t         Files specific to ARM 720 CPUs
       /arm920t         Files specific to ARM 920 CPUs
-        /at91rm9200    Files specific to Atmel AT91RM9200 CPU
-        /imx           Files specific to Freescale MC9328 i.MX CPUs
-        /s3c24x0       Files specific to Samsung S3C24X0 CPUs
+       /at91rm9200     Files specific to Atmel AT91RM9200 CPU
+       /imx            Files specific to Freescale MC9328 i.MX CPUs
+       /s3c24x0        Files specific to Samsung S3C24X0 CPUs
       /arm925t         Files specific to ARM 925 CPUs
       /arm926ejs       Files specific to ARM 926 CPUs
       /arm1136         Files specific to ARM 1136 CPUs
@@ -177,9 +177,6 @@ Directory Hierarchy:
   /mips                        Files generic to MIPS architecture
     /cpu               CPU specific files
     /lib               Architecture specific library files
-  /nios                        Files generic to Altera NIOS architecture
-    /cpu               CPU specific files
-    /lib               Architecture specific library files
   /nios2               Files generic to Altera NIOS2 architecture
     /cpu               CPU specific files
     /lib               Architecture specific library files
@@ -1498,6 +1495,16 @@ The following options need to be configured:
 
                #define I2C_DELAY  udelay(2)
 
+               CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
+
+               If your arch supports the generic GPIO framework (asm/gpio.h),
+               then you may alternatively define the two GPIOs that are to be
+               used as SCL / SDA.  Any of the previous I2C_xxx macros will
+               have GPIO-based defaults assigned to them as appropriate.
+
+               You should define these to the GPIO value as given directly to
+               the generic GPIO functions.
+
                CONFIG_SYS_I2C_INIT_BOARD
 
                When a board is reset during an i2c bus transfer
@@ -2507,7 +2514,7 @@ to save the current settings.
          I2C muxes, you can define here, how to reach this
          EEPROM. For example:
 
-         #define CONFIG_I2C_ENV_EEPROM_BUS       "pca9547:70:d\0"
+         #define CONFIG_I2C_ENV_EEPROM_BUS       "pca9547:70:d\0"
 
          EEPROM which holds the environment, is reached over
          a pca9547 i2c mux with address 0x70, channel 3.
@@ -2565,7 +2572,7 @@ to save the current settings.
 
 Please note that the environment is read-only until the monitor
 has been relocated to RAM and a RAM copy of the environment has been
-created; also, when using EEPROM you will have to use getenv_r()
+created; also, when using EEPROM you will have to use getenv_f()
 until then to read environment variables.
 
 The environment is protected by a CRC32 checksum. Before the monitor
@@ -3151,10 +3158,10 @@ List of environment variables (most likely not complete):
                  interface is currently active. For example you
                  can do the following
 
-                 => setenv ethact FEC ETHERNET
-                 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
-                 => setenv ethact SCC ETHERNET
-                 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
+                 => setenv ethact FEC
+                 => ping 192.168.0.1 # traffic sent on FEC
+                 => setenv ethact SCC
+                 => ping 10.0.0.1 # traffic sent on SCC
 
   ethrotate    - When set to "no" U-Boot does not go through all
                  available network interfaces.
@@ -3303,6 +3310,11 @@ o If both the SROM and the environment contain a MAC address, and the
 o If neither SROM nor the environment contain a MAC address, an error
   is raised.
 
+If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
+will be programmed into hardware as part of the initialization process.  This
+may be skipped by setting the appropriate 'ethmacskip' environment variable.
+The naming convention is as follows:
+"ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
 
 Image Formats:
 ==============
@@ -3332,8 +3344,8 @@ details; basically, the header defines the following image properties:
   Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
   INTEGRITY).
 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
-  IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
-  Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
+  IA64, MIPS, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
+  Currently supported: ARM, AVR32, Intel x86, MIPS, Nios II, PowerPC).
 * Compression Type (uncompressed, gzip, bzip2)
 * Load Address
 * Entry Point
@@ -4018,6 +4030,14 @@ On ARM, the following registers are used:
 
     ==> U-Boot will use R8 to hold a pointer to the global data
 
+On Nios II, the ABI is documented here:
+       http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
+
+    ==> U-Boot will use gp to hold a pointer to the global data
+
+    Note: on Nios II, we give "-G0" option to gcc and don't use gp
+    to access small data sections, so gp is free.
+
 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
 or current versions of GCC may "optimize" the code too much.