If the `CAN_USE_HEAP` bit is set, we put `heap_end_ptr` into `dx` (which points to `_end`) and add `STACK_SIZE` (minimum stack size, `512` bytes) to it. After this, if `dx` is not carried (it will not be carried, `dx = _end + 512`), jump to label `2` (as in the previous case) and make a correct stack.
If the `CAN_USE_HEAP` bit is set, we put `heap_end_ptr` into `dx` (which points to `_end`) and add `STACK_SIZE` (minimum stack size, `1024` bytes) to it. After this, if `dx` is not carried (it will not be carried, `dx = _end + 1024`), jump to label `2` (as in the previous case) and make a correct stack.
which means `heap_end_ptr` or `_end` + `512`(`0x200h`). The last check is whether `heap_end` is greater than `stack_end`. If it is then `stack_end` is assigned to `heap_end` to make them equal.
which means `heap_end_ptr` or `_end` + `512` (`0x200h`). The last check is whether `heap_end` is greater than `stack_end`. If it is then `stack_end` is assigned to `heap_end` to make them equal.
Now the heap is initialized and we can use it using the `GET_HEAP` method. We will see how it is used, how to use it and how it is implemented in the next posts.