Changing machine name u540 to u740 in local.conf file

Earlier i built an image with machine freedom-u540, it built successful.
Now, I am trying to build with machine freedom-u740, I am getting errors for following commands,

$ bitbake-layers add-layer …/meta-riscv/
{{{
riscv-yocto/openembedded-core/build$ bitbake-layers add-layer …/meta-riscv/
NOTE: Reconnecting to bitbake server…
NOTE: Retrying server connection (#1)…
NOTE: Reconnecting to bitbake server…
NOTE: Reconnecting to bitbake server…
NOTE: Retrying server connection (#1)…
NOTE: Retrying server connection (#1)…
NOTE: Reconnecting to bitbake server…
NOTE: Retrying server connection (#2)…
NOTE: Reconnecting to bitbake server…
NOTE: Reconnecting to bitbake server…
NOTE: Retrying server connection (#2)…
NOTE: Retrying server connection (#2)…
NOTE: Reconnecting to bitbake server…
NOTE: Retrying server connection (#3)… (Traceback (most recent call last):
File “/home/megha/Exaleap-yocto/riscv-yocto/openembedded-core/bitbake/lib/bb/main.py”, line 455, in setup_bitbake
server_connection = bb.server.process.connectProcessServer(sockname, featureset)
File “/home/megha/Exaleap-yocto/riscv-yocto/openembedded-core/bitbake/lib/bb/server/process.py”, line 490, in connectProcessServer
sock.connect(os.path.basename(sockname))
BlockingIOError: [Errno 11] Resource temporarily unavailable
}}}

$ bitbake core-image-minimal
{{{
riscv-yocto/openembedded-core/build$ bitbake core-image-minimal
NOTE: Reconnecting to bitbake server…
NOTE: Retrying server connection (#1)… (Traceback (most recent call last):
File “/home/megha/Exaleap-yocto/riscv-yocto/openembedded-core/bitbake/lib/bb/main.py”, line 455, in setup_bitbake
server_connection = bb.server.process.connectProcessServer(sockname, featureset)
File “/home/megha/Exaleap-yocto/riscv-yocto/openembedded-core/bitbake/lib/bb/server/process.py”, line 490, in connectProcessServer
sock.connect(os.path.basename(sockname))
BlockingIOError: [Errno 11] Resource temporarily unavailable
)
NOTE: Reconnecting to bitbake server…
NOTE: Retrying server connection (#2)… (Traceback (most recent call last):
File “/home/megha/Exaleap-yocto/riscv-yocto/openembedded-core/bitbake/lib/bb/main.py”, line 455, in setup_bitbake
server_connection = bb.server.process.connectProcessServer(sockname, featureset)
File “/home/megha/Exaleap-yocto/riscv-yocto/openembedded-core/bitbake/lib/bb/server/process.py”, line 490, in connectProcessServer
sock.connect(os.path.basename(sockname))
BlockingIOError: [Errno 11] Resource temporarily unavailable
)
NOTE: Reconnecting to bitbake server…
NOTE: Retrying server connection (#3)… (Traceback (most recent call last):
File “/home/megha/Exaleap-yocto/riscv-yocto/openembedded-core/bitbake/lib/bb/main.py”, line 455, in setup_bitbake
server_connection = bb.server.process.connectProcessServer(sockname, featureset)
File “/home/megha/Exaleap-yocto/riscv-yocto/openembedded-core/bitbake/lib/bb/server/process.py”, line 490, in connectProcessServer
sock.connect(os.path.basename(sockname))
BlockingIOError: [Errno 11] Resource temporarily unavailable
}}}

The documented values for MACHINE are qemuriscv32, qemuriscv64, and freedom-u540.

Why are you trying to use freedom-u740? Did you add your own private support for that? If so, there is probably a bug in your patches.