Doesn't recognize only up to 128mb of ram

[AKUSIROYO]

It's probably the exact same hardware as the netbook you have except for the memory, and it has 256mb of memory.
However, when I booted the v7 release on my netbook, it recognized only 128mb of memory.
When I start with a value like mem=256M in bootargs, instead of starting Windows CE, the screen goes black, so uboot seems to be starting, but it just gets stuck.
To be more precise, it will start normally when mem=128mb or less, but will not start if it is more than that.
Other parts are working perfectly (wifi, etc.)

I'm using translation software, so I apologize if there are any inappropriate expressions.

[wh0]

I could only refer you to this discussion https://groups.google.com/g/vt8500-wm8505-linux-kernel/c/9c9GjUnMHz4/m/lKjrm1IdAwAJ which says something about setting cma=