Bootloader does not map all required pages

So I have no idea where to put this, though I've spoke about it in various places and have gotten no response in a month or so. (I apologize if I seem impatient.) It doesn't appear like the bootloader is mapping all of the required paged memory regions that my kernel uses. This in turn makes it prohibitive to continue my project because I have no idea why this is even happening to begin with. My debugging has lead me -- repeatedly -- to conclude that its a bug when x86_64 goes to zero an entry in one of the paging structures, though which one I am unclear about. Specifically, it occurs when allocating the kernel heap. When my kernel attempts to allocate address 3000h (or, rather, 18000003000h) I get a #PF, but since (for some reason) my IDT is being ignored (presumably it isn't mapped yet) a page fault occurs. Then another occurs because the ISRs aren't mapped, and then a double fault occurs, and then a triple fault. It has gotten to the point where I'm considering just making my own paging structures and not using the bootloader-provided ones. I want to avoid that but if there is truly no solution to this then I won't have much of a choice. My code is available here. Does anyone know why this is happening? Is there something I'm missing? From what I can tell the bootloader sets CR3 and (appears) to map everything but the behavior of my kernel leads me to believe otherwise.

Begin with the linked kernel repository and the x86_64 boot path, focusing on CR3 setup, paging structures, kernel-heap allocation at 18000003000h, and IDT/ISR mapping. Reproduce the page-fault cascade and compare the bootloader-provided mappings with the regions the kernel accesses; done when the required pages and fault handlers remain available during allocation.