hi， nxp：
According to the protocol stack demo of tcp/ip stack, we changed the compilation environment from the previous windows to linux, and then the loopback mode of GMAC could not succeed.
The function Gmac_Ip_GetTransmitStatus return value is GMAC_STATUS_BUSY.
we compare the two compilation environment GMAC regs value as picture bellow.
The registers in your pasted picture is belong to GMAC DMA channel 0 Tx and Rx descriptor ring.
That is reasonable when using difference compile project, the Tx, Rx descriptor ring location change when use difference compile environment. That isn't one problem.
The reason of "GMAC_STATUS_BUSY", please check whether the GMAC clock is locked or not.
Please check the MC_CGM_0 MUX_9, MUX_10, MUX_11 and MUX_15.
The clock chart is as below picture:
