HPS2FPGA bridge on DE0-Nano-SoC (5CSEMA4U23C6N) and GHRD

I've solved the problem!

First of all, the AXI data is plased where it should be: at 0xC0000000 offset. The readdata width of the Avalon MM module is truncated to 32 bits so it should be 32 bits to not been truncated. The test module just output the requested address as the readdata value:

module MY_AVALON_MEMORY(clk, resetn, readdata, address);
    input clk;
    input resetn;
    input  address;
    output  readdata;
    
    assign readdata = address;
    
endmodule

Below are the most important parts of C program to print this:

# define ALT_FPGASLVS_OFST ( 0xC0000000 )
...
    void *virtual_base;
    int fd;
    fd = open( "/dev/mem", ( O_RDWR | O_SYNC ) );
    virtual_base = mmap( NULL, HW_REGS_SPAN, ( PROT_READ | PROT_WRITE ), MAP_SHARED, fd, ALT_FPGASLVS_OFST );
    void *mem_addr;
    void *mem_max;
    uint32_t v;
    mem_addr = virtual_base + ( ( unsigned long  )( MY_MEMORY_0_BASE )); //This two constants are taken from the header which is generated by the generate_hps_qsys_header.sh
    mem_max = virtual_base + ( ( unsigned long  )( MY_MEMORY_0_END ));
    while (mem_addr < mem_max) {
        v = *((uint32_t *) mem_addr);
        printf("%08X\t%08X\n", (unsigned int) mem_addr, (unsigned int) v);
        mem_addr += sizeof(uint32_t);        
    }
    close( fd );    

The result are two pretty nice columns full of data:

72E19000        00000000
72E19004        00000001
72E19008        00000002
72E1900C        00000003
72E19010        00000004
72E19014        00000005
72E19018        00000006
72E1901C        00000007
72E19020        00000008
72E19024        00000009
72E19028        0000000A
72E1902C        0000000B
72E19030        0000000C
72E19034        0000000D
72E19038        0000000E
72E1903C        0000000F
72E19040        00000010
72E19044        00000011
72E19048        00000012
72E1904C        00000013
72E19050        00000014
72E19054        00000015
72E19058        00000016
72E1905C        00000017
72E19060        00000018
72E19064        00000019
72E19068        0000001A
72E1906C        0000001B
72E19070        0000001C
72E19074        0000001D
72E19078        0000001E
72E1907C        0000001F