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Ethernet interrupt vectors for sabrelite machine are defined backwards

The sabrelite machine model used by qemu-system-arm is based on the Freescale/NXP i.MX6Q processor. This SoC has an on-board ethernet controller which is supported in QEMU using the imx_fec.c module (actually called imx.enet for this model.)

The include/hw/arm/fsm-imx6.h file defines the interrupt vectors for the imx.enet device like this:

#define FSL_IMX6_ENET_MAC_1588_IRQ 118
#define FSL_IMX6_ENET_MAC_IRQ 119

However, this is backwards. The reference manual for the i.MX6D/Q devices can be found here:

https://www.nxp.com/docs/en/reference-manual/IMX6DQRM.pdf

On page 225, in Table 3-1. ARM Cortex A9 domain interrupt summary, it shows the following:

150 ENET
MAC 0 IRQ, Logical OR of:
MAC 0 Periodic Timer Overflow
MAC 0 Time Stamp Available
MAC 0 Time Stamp Available
MAC 0 Time Stamp Available
MAC 0 Payload Receive Error
MAC 0 Transmit FIFO Underrun
MAC 0 Collision Retry Limit
MAC 0 Late Collision
MAC 0 Ethernet Bus Error
MAC 0 MII Data Transfer Done
MAC 0 Receive Buffer Done
MAC 0 Receive Frame Done
MAC 0 Transmit Buffer Done
MAC 0 Transmit Frame Done
MAC 0 Graceful Stop
MAC 0 Babbling Transmit Error
MAC 0 Babbling Receive Error
MAC 0 Wakeup Request [synchronous]

151 ENET
MAC 0 1588 Timer interrupt [synchronous] request

Note:
150 - 32 == 118
151 - 32 == 119

In other words, the vector definitions in the fsl-imx6.h file are reversed. The correct definition is:

#define FSL_IMX6_ENET_MAC_IRQ 118
#define FSL_IMX6_ENET_MAC_1588_IRQ 119

I tested the sabrelite simulation using VxWorks 7 (which supports the SabreLite board) and found that while I was able to send and receive packet data via the simulated ethernet interface, the VxWorks i.MX6 ethernet driver failed to receive any interrupts. When I corrected the interrupt vector definitions as shown above and recompiled QEMU, everything worked as expected. I was able to exchange ICMP packets with the simulated target and telnet to/from the VxWorks instance running in the virtual machine. I used the tap interface for this.

As a workaround I was also able to make the ethernet work by modifying the VxWorks imx6q-sabrelite.dts file to change the ethernet interrupt property from 150 to 151.

This problem was observed with the following environment:

Host: FreeBSD/amd64 11.1-RELEASE
QEMU version: 2.11.0 and 2.11.1 built from source code