Add documentation for new "pcap" command.
Signed-off-by: Ramon Fried rfried.dev@gmail.com
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Changes in v4: * Document the new $pcapsize environment variable. * update doc regarding error message when there's not enough memory left.
Changes in v3: None Changes in v2: None
doc/README.pcap | 62 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 doc/README.pcap
diff --git a/doc/README.pcap b/doc/README.pcap new file mode 100644 index 0000000000..97b3e55fd8 --- /dev/null +++ b/doc/README.pcap @@ -0,0 +1,62 @@ +PCAP: + +U-boot supports live Ethernet packet capture in PCAP(2.4) format. +This is enabled by CONFIG_CMD_PCAP. + +The capture is stored on physical memory, and should be copied to +a machine capable of parsing and displaying PCAP files (IE. wireshark) +If networking works properly one can copy the capture file from physical memory +using tftpput, or save it to local storage with (sf write, mmc write, fatwrite, etc) + +the pcap capturing requires maximum buffer size. +when the buffer is full an error message will be displayed and then packets +will silently drop. +the actual capture file size is populate in the environment variable "pcapsize". + +Usage example: + +# Initialize pcap capture to physical address (0x100000) with maximum size of +# 100000 bytes. + +# Start capture +pcap start + +# Initialize network activity +env set ipaddr 10.0.2.15; env set serverip 10.0.2.2; tftp uImage64 + +# Stop capture +pcap stop + +# pcap init 0x100000 100000 +PCAP capture initialized: addr: 0xffffffff80100000 max length: 100000 + +# pcap start +# env set ipaddr 10.0.2.15; env set serverip 10.0.2.2; tftp uImage64 +eth0@10000000: PHY present at 0 +eth0@10000000: link up, 1000Mbps full-duplex (lpa: 0x7c00) +Using eth0@10000000 device +TFTP from server 10.0.2.2; our IP address is 10.0.2.15 +Filename 'uImage64'. +Load address: 0xffffffff88000000 +Loading: ################################################################# + ################################################################# + ################################################################# + ################################################################# +!!! Buffer is full, consider increasing buffer size !!! + ################################################################# + ################################################################# + ################################################################# + ################################################################# + ################################################################# + # + 18.2 MiB/s +done +Bytes transferred = 8359376 (7f8dd0 hex) +PCAP status: + Initialized addr: 0xffffffff80100000 max length: 100000 + Status: Active. file size: 99991 + Incoming packets: 66 Outgoing packets: 67 + +# pcap stop +# tftpput 0xffffffff80100000 $pcapsize 10.0.2.2:capture.pcap +