This patch fixes build failures of the virtio_trans driver (Cortex-A9, 32-bit ARM)
when building a PREEMPT_RT-enabled kernel. The errors were caused by
unresolved 64-bit division symbols (__aeabi_uldivmod / __aeabi_ldivmod)
generated when the driver was compiled as a module.
Changes included:
* virtio_trans.c:
- Replace 64-bit modulus operations (`idx % vt->{tx,rx}_vring_size`) with
kernel-safe 64-bit division macros using `div_u64_rem()`.
This prevents implicit calls to non-exported ARM EABI helpers that are not
available to kernel modules on 32-bit ARM.
* fragment-nxp-rt.config:
- Enable the mailbox framework (`CONFIG_MAILBOX=y`) required by virtio
mailbox-based transports.
- Build the virtio transport driver into the kernel (`CONFIG_VIRTIO_TRANS=y`)
instead of as a module, ensuring proper symbol resolution
during link time. Without this a license error is shown when building
the kernel in yocto.
https://onedigi.atlassian.net/browse/DEL-9783
Signed-off-by: Francisco Gil <francisco.gilmartinez@digi.com>
Add a unique patch with the RT functionality between NXP tags (sha1)
'lf-6.6.36-2.1.0' (d23d64eea5111e1607efcce1d601834fceec92cb)
'Real-Time-Edge-v3.1-202503' (f03af81d60b7ae14e03fafa8f4c4289c30a73f93)
https://onedigi.atlassian.net/browse/DEL-9324
Signed-off-by: Isaac Hermida <isaac.hermida@digi.com>
Francisco Gil
Isaac Hermida