Changing the chip configuration live

It is possible to change configuration variables (config) and reinitialise the SDK (init) at runtime — with SONiC left inconsistent until syncd is restarted or the switch rebooted. Combined with runtime lane changes on port, this allows experimenting with breakout configurations.

Invalid configurations are rejected by the SDK’s port configuration checks:

Unvalidated

drivshell> config portmap_69=77:40
drivshell> init all
Port 69 bandwidth 40 Gb and port 70 can not be both configured
Port 69 bandwidth 40 Gb and port 71 can not be both configured
Port 69 bandwidth 40 Gb and port 72 can not be both configured
PGW_CL4 and PGW_CL5 total line rate bandwidth (230 Gb) exceeds 200 Gb
0:soc_info_config: Port config error !!
0:system_init: system_init: Device reset failed: Invalid configuration

Unvalidated

drivshell> config portmap_70=78:10:i
drivshell> config portmap_71=79:10:i
drivshell> config portmap_72=80:10:i
drivshell> init all
0:soc_egress_drain_cells: MacDrainTimeOut:port 0,xe46, timeout draining packets
0:soc_egress_drain_cells: MacDrainTimeOut:port 0,xe47, timeout draining packets
0:soc_egress_drain_cells: MacDrainTimeOut:port 0,xe46, timeout draining packets
0:soc_egress_drain_cells: MacDrainTimeOut:port 0,xe47, timeout draining packets
0:bcmi_xgs5_bfd_init: uKernel BFD application not available