dbg_start()

The dbg_start() function starts the debug agent drivers and the debug agent (see "The Debug Agent"). Example 4-7 is dbg_start() source code provided in source_dir/nucleus/bsp/src/boot_tools/dbg_start.c.

Example 4-7 dbg_start()

    void
dbg_start(void* cookie)
{
    int i;

    /*
     * Launch debuging console driver
     */
    for (i = 0; i < bootConf->numBins; ++i) {
        BinDesc* bin = &bootConf->binDesc[i];
        if (bin->type == BIN_DBG_DRIVER) {
            (* (DbgDriverEntry) bin->entry)(bootConf, cookie);
        }
    }

    /*
     * Launch debuging agent
     */
    for (i = 0; i < bootConf->numBins; ++i) {
        BinDesc* bin = &bootConf->binDesc[i];
        if (bin->type == BIN_DBG_AGENT) {
            (* (DbgAgentEntry) bin->entry)(bootConf);
        }
    }

    _stdc_consInit(bootConf->dbgOps.consRead,
                   bootConf->dbgOps.consWrite);
}

The dbg_start() function retrieves the descriptor pointing to the debug agent driver binary from the BootConf structure. It then calls the debug agent driver's entry point, passing it the address of the BootConf structure and the opaque value that came from the initial loader. Once the driver has been started, dbg_start() retrieves the descriptor pointing to the debug agent itself. It calls the debug agent entry point, passing it the address of BootConf.

The dbg_start() function assumes that the debug agent and its driver are already installed.

Finally, dbg_start() makes console I/O available for the bootstrap program by initializing its printf()/scanf() support library.