Yep that is what you want.
The u32 sector_size is the location where the value will be stored. The §or_size passes the address of the variable to the function. If you don't pass the address any changes will be lost when the function returns. This is one way in which a function can return data. The others are by a return value (but, you're limited to one value), a pointer, or a pointer to a pointer. Pointers are typically only used for buffers. A pointer to a pointer is used if the function will allocate memory.
The u32 sector_size is the location where the value will be stored. The §or_size passes the address of the variable to the function. If you don't pass the address any changes will be lost when the function returns. This is one way in which a function can return data. The others are by a return value (but, you're limited to one value), a pointer, or a pointer to a pointer. Pointers are typically only used for buffers. A pointer to a pointer is used if the function will allocate memory.