GCC have not been capable enough to catch some linker errors which arose when
ethernet support for LWIP was disabled. Checks have been added to make sure that
unrefrenced code is not linked in.
nsapi_ppp glue layer is made more transparent to public cellular API. Storage of IP
addresses is removed. PPP layer already stores the addresses, so we pass the pointer back
to the upper layers.
If PPP is not used, we provide dummy functions.
* state machine corrections
* adding various standard API methods
* Addition/revision/enhancement of the nsapi_ppp glue layer
* Turning off debug by default
Originally the ethernet ISR would be linked in to all mbed-os based
firmware because it was named ENET_IRQHandler() so that it would be
automatically placed in the FLASH image's interrupt vector table. This
meant that programs which made no use of the lwIP stack still pulled in
this ISR.
This commit changes the name of the routine so that the ISR isn't
automatically placed in the interrupt vector table at link time but is
instead dynamically placed in the interrupt vector table at runtime
when the lwIP stack is initialized. Now the ethernet ISR is only linked
in when it is actually needed.
Example arm-none-eabi-size output for a simple LED blinking program
showing the before and after size results:
text data bss dec hex filename
13208 148 7784 21140 5294 LPC1768/HelloWorld.elf
text data bss dec hex filename
12700 148 7468 20316 4f5c LPC1768/HelloWorld.elf
From opt.h:
IP_SOF_BROADCAST_RECV (requires IP_SOF_BROADCAST=1) enable the broadcast
filter on recv operations.
The IP_SOF_BROADCAST_RECV option does not enable or disable recieving
broadcast packets, it only enables a software filter.
Previously, exhausting hardware buffers would begin blocking the lwip
thread. This patch changes the emac layer to simply drop ethernet
frames, leaving recovery up to a higher level protocol.
This is consistent with the behaviour of the emac layer when unable
to allocate dynamic memory.
This was actually several bugs colluding together.
1. Confusion on the buffer-semaphore paradigm used led to misuse of the
tx semaphore and potential for odd behaviour.
2. Equality tests on tx_consume_index and tx_produce_index did not
handle overflow correctly. This would allow tx_consume_index to catch
up to tx_produce_index and trick the k64f_rx_reclaim function into
forgetting about a whole buffer of pbufs.
3. On top of all of that, the ENET_BUFFDESCRIPTOR_TX_READ_MASK was not
correctly read immediately after being set due to either a compiler
optimization or hardware delays. This caused k64f_low_level_output
to eagerly overrun existing buff-descriptors before they had been
completely sent. Adopting the counting-semaphore paradigm for 1 avoided
this concern.
As pointed out by @infinnovation, the overflow only occurs in the rare
case that the 120MHz CPU can actually generate packets faster than the
ENET hardware can transmit on a 100Mbps link.