Simulink, How does this m-code block work while having input mismatch?

Question

In MATLAB Simulink, I added an MPC (Model predictive control block).

I looked inside this block:

Inside it there is a wrapper subsystem called MPC. I opened this one via double click:

The main block inside this subsystem is optimizer. This block is a m-code block starting with this header:

function [xk1, u, cost, useq, status, xest, iAout] = fcn(...
            xk, old_u, ym, ref, md, umin, umax, ymin, ymax, switch_in, ext_mv, MVtarget, isQP, nx, nu, ny, degrees, Hinv, Kx, Ku1, Kut, Kr, Kv, Mlim, ...
            Mx, Mu1, Mv, z_degrees, utarget, p, uoff, voff, yoff, maxiter, nxQP, openloopflag, ...
            lims_inport, no_umin, no_umax, no_ymin, no_ymax, switch_inport, no_switch, enable_value, ...
            return_cost, H, return_sequence, Linv, Ac, ...
            ywt, uwt, duwt, rhoeps, iA, ...
            no_ywt, no_uwt, no_duwt, no_rhoeps,...
            Wy, Wdu, Jm, SuJm, Su1, Sx, Hv, Wu, I1, ...
            A, Bu, Bv, C, Dv, Mrows, nCC, Ecc, Fcc, Scc, Gcc, ...
            nv, no_md, no_ref, no_uref, no_mv, Rscale, MDscale, myindex, ...
            myoff, xoff, CustomEstimation, M, L)
%#codegen
coder.extrinsic('mpcblock_optimizer_double_mex');
coder.extrinsic('mpcblock_optimizer_single_mex');
coder.extrinsic('mpcblock_refmd_double_mex');
coder.extrinsic('mpcblock_refmd_single_mex');

My question is that why the number of inputs of the function in the code is much higher than the number of inputs ports of this block in simulink. Where are these variables generated? For example how is argument H created before this function is called?

Here the Simulink file is attached:

https://www.dropbox.com/s/vx67urpkt9qki9e/simulink.zip?dl=0

Answer 1

I suspect some of the "inputs" are not actually inputs, but parameters passed to the function. See Add Parameter Arguments in the documentation for more details.

Answer 2

For a Matlab Function block, there are two types of input arguments to the m-code. The input signals you already know and parameters. Go to edit data, you will see which are switched to paremeter, these variables come from a mask or your workspace.