Add env vars describing U-Boot target board

[u-boot.git] / README

diff --git a/README b/README
index 79016e690ace8899488e54ee7a35e1715018e9a2..dac46f35b2e337e98961b10ea087e112eb374cb2 100644 (file)
--- a/README
+++ b/README
@@ -374,6 +374,15 @@ The following options need to be configured:
                Defines the string to utilize when trying to match PCIe device
                tree nodes for the given platform.
 
+               CONFIG_SYS_PPC_E500_DEBUG_TLB
+
+               Enables a temporary TLB entry to be used during boot to work
+               around limitations in e500v1 and e500v2 external debugger
+               support. This reduces the portions of the boot code where
+               breakpoints and single stepping do not work.  The value of this
+               symbol should be set to the TLB1 entry to be used for this
+               purpose.
+
 - Generic CPU options:
                CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
 
@@ -432,6 +441,14 @@ The following options need to be configured:
                Select high exception vectors of the ARM core, e.g., do not
                clear the V bit of the c1 register of CP15.
 
+               CONFIG_SYS_THUMB_BUILD
+
+               Use this flag to build U-Boot using the Thumb instruction
+               set for ARM architectures. Thumb instruction set provides
+               better code density. For ARM architectures that support
+               Thumb2 this flag will result in Thumb2 code generated by
+               GCC.
+
 - Linux Kernel Interface:
                CONFIG_CLOCKS_IN_MHZ
 
@@ -777,6 +794,8 @@ The following options need to be configured:
                CONFIG_CMD_JFFS2        * JFFS2 Support
                CONFIG_CMD_KGDB         * kgdb
                CONFIG_CMD_LDRINFO        ldrinfo (display Blackfin loader)
+               CONFIG_CMD_LINK_LOCAL   * link-local IP address auto-configuration
+                                         (169.254.*.*)
                CONFIG_CMD_LOADB          loadb
                CONFIG_CMD_LOADS          loads
                CONFIG_CMD_MD5SUM         print md5 message digest
@@ -1584,10 +1603,17 @@ The following options need to be configured:
                CONFIG_BOOTP_NTPSERVER
                CONFIG_BOOTP_TIMEOFFSET
                CONFIG_BOOTP_VENDOREX
+               CONFIG_BOOTP_MAY_FAIL
 
                CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
                environment variable, not the BOOTP server.
 
+               CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
+               after the configured retry count, the call will fail
+               instead of starting over.  This can be used to fail over
+               to Link-local IP address configuration if the DHCP server
+               is not available.
+
                CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
                serverip from a DHCP server, it is possible that more
                than one DNS serverip is offered to the client.
@@ -1618,6 +1644,14 @@ The following options need to be configured:
                the DHCP timeout and retry process takes a longer than
                this delay.
 
+ - Link-local IP address negotiation:
+               Negotiate with other link-local clients on the local network
+               for an address that doesn't require explicit configuration.
+               This is especially useful if a DHCP server cannot be guaranteed
+               to exist in all environments that the device must operate.
+
+               See doc/README.link-local for more information.
+
  - CDP Options:
                CONFIG_CDP_DEVICE_ID
 
@@ -2195,6 +2229,20 @@ The following options need to be configured:
                the environment like the "source" command or the
                boot command first.
 
+               CONFIG_ENV_VARS_UBOOT_CONFIG
+
+               Define this in order to add variables describing the
+               U-Boot build configuration to the default environment.
+               These will be named arch, cpu, board, vendor, and soc.
+
+               Enabling this option will cause the following to be defined:
+
+               - CONFIG_SYS_ARCH
+               - CONFIG_SYS_CPU
+               - CONFIG_SYS_BOARD
+               - CONFIG_SYS_VENDOR
+               - CONFIG_SYS_SOC
+
 - DataFlash Support:
                CONFIG_HAS_DATAFLASH