Update bcm2711_bootloader_config.md (raspberrypi#1682)

timg236 · web-flow · commit 73eccd65af8a · 2020-09-23T12:29:09.000+01:00
* Update bcm2711_bootloader_config.md

Document max length limitations and default values for the NETCONSOLE property

* Update bcm2711_bootloader_config.md
diff --git a/hardware/raspberrypi/bcm2711_bootloader_config.md b/hardware/raspberrypi/bcm2711_bootloader_config.md
@@ -146,6 +146,7 @@ Version: 2020-04-16
 Specify the custom directory prefix string used when `TFTP_PREFIX` is set to 1. For example:- `TFTP_PREFIX_STR=tftp_test/`
 
 Default: ""  
+Max length: 32 characters  
 Version: 2020-04-16  
 
 ### PXE_OPTION43
@@ -228,22 +229,28 @@ N.B. NETCONSOLE blocks until the ethernet link is established or a timeout occur
 #### Format
 See https://wiki.archlinux.org/index.php/Netconsole
 ```
-src_port@src_ip/dev_name,dst_port@tgt_ip/tgt_mac
-E.g. 6665@169.254.1.1/eth0,6666@/
+src_port@src_ip/dev_name,dst_port@dst_ip/dst_mac
+E.g. 6665@169.254.1.1/,6666@/
 ```
-In order to simplify parsing, the bootloader requires every field separator to be present. In the example the target IP address (255.255.255.255) and target mac address (00:00:00:00:00) are assigned default values.
+In order to simplify parsing, the bootloader requires every field separator to be present. The source ip address must be specified but the following fields may be left blank and assigned default values.
+
+* src_port - 6665
+* dev_name - "" (the device name is always ignored)
+* dst_port - 6666
+* dst_ip - 255.255.255.255
+* dst_mac - 00:00:00:00:00
 
 One way to view the data is to connect the test Pi 4 to another Pi running WireShark and select “udp.srcport == 6665” as a filter and select `Analyze -> Follow -> UDP stream` to view as an ASCII log.
 
 `NETCONSOLE` should not be enabled by default because it may cause network problems. It can be enabled on demand via a GPIO filter e.g.
 ```
 # Enable debug if GPIO 7 is pulled low
 [gpio7=0]
-BOOT_UART=1
-NETCONSOLE=6665@169.254.1.1/eth0,6666@/
+NETCONSOLE=6665@169.254.1.1/,6666@/
 ```
 
-Default: ""  
+Default: ""  (not enabled)  
+Max length: 32 characters  
 Version: 2020-09-03  
 
 ### USB_MSD_EXCLUDE_VID_PID
