doc: zynq: Describe status of zc770-xm011

[people/ms/u-boot.git] / README

diff --git a/README b/README
index 2df0e1f8a78e66f075a6c5c0991402440f064c4f..b53ea7dfe3f6d8201d75135ffd001e4f7c19a96a 100644 (file)
--- a/README
+++ b/README
@@ -143,6 +143,7 @@ Directory Hierarchy:
   /nios2               Files generic to Altera NIOS2 architecture
   /openrisc            Files generic to OpenRISC architecture
   /powerpc             Files generic to PowerPC architecture
+  /riscv               Files generic to RISC-V architecture
   /sandbox             Files generic to HW-independent "sandbox"
   /sh                  Files generic to SH architecture
   /x86                 Files generic to x86 architecture
@@ -1603,6 +1604,15 @@ The following options need to be configured:
 
                See doc/README.link-local for more information.
 
+ - MAC address from environment variables
+
+               FDT_SEQ_MACADDR_FROM_ENV
+
+               Fix-up device tree with MAC addresses fetched sequentially from
+               environment variables. This config work on assumption that
+               non-usable ethernet node of device-tree are either not present
+               or their status has been marked as "disabled".
+
  - CDP Options:
                CONFIG_CDP_DEVICE_ID
 
@@ -2168,16 +2178,6 @@ The following options need to be configured:
                currently only supports clearing the memory.
 
 - Error Recovery:
-               CONFIG_PANIC_HANG
-
-               Define this variable to stop the system in case of a
-               fatal error, so that you have to reset it manually.
-               This is probably NOT a good idea for an embedded
-               system where you want the system to reboot
-               automatically as fast as possible, but it may be
-               useful during development since you can try to debug
-               the conditions that lead to the situation.
-
                CONFIG_NET_RETRY_COUNT
 
                This variable defines the number of retries for
@@ -3511,7 +3511,7 @@ Low Level (hardware related) configuration options:
                globally (CONFIG_CMD_MEMORY).
 
 - CONFIG_SKIP_LOWLEVEL_INIT
-               [ARM, NDS32, MIPS only] If this variable is defined, then certain
+               [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain
                low level initializations (like setting up the memory
                controller) are omitted and/or U-Boot does not
                relocate itself into RAM.
@@ -4965,6 +4965,22 @@ On NDS32, the following registers are used:
 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
 or current versions of GCC may "optimize" the code too much.
 
+On RISC-V, the following registers are used:
+
+       x0: hard-wired zero (zero)
+       x1: return address (ra)
+       x2:     stack pointer (sp)
+       x3:     global pointer (gp)
+       x4:     thread pointer (tp)
+       x5:     link register (t0)
+       x8:     frame pointer (fp)
+       x10-x11:        arguments/return values (a0-1)
+       x12-x17:        arguments (a2-7)
+       x28-31:  temporaries (t3-6)
+       pc:     program counter (pc)
+
+    ==> U-Boot will use gp to hold a pointer to the global data
+
 Memory Management:
 ------------------
 
@@ -5126,8 +5142,9 @@ Coding Standards:
 -----------------
 
 All contributions to U-Boot should conform to the Linux kernel
-coding style; see the file "Documentation/CodingStyle" and the script
-"scripts/Lindent" in your Linux kernel source directory.
+coding style; see the kernel coding style guide at
+https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
+script "scripts/Lindent" in your Linux kernel source directory.
 
 Source files originating from a different project (for example the
 MTD subsystem) are generally exempt from these guidelines and are not