Function InitializeTSS

Kernel/src/arch/x86_64/tss.cpp:12–40

namespace TSS
{
    void InitializeTSS(tss_t* tss, void* gdt){

        LoadTSS((uintptr_t)tss, (uint64_t)gdt, 0x28);

        memset(tss, 0, sizeof(tss_t));
        
        // Set up Interrupt Stack Tables
        tss->ist1 = (uint64_t)Memory::KernelAllocate4KPages(8);
        tss->ist2 = (uint64_t)Memory::KernelAllocate4KPages(8);
        tss->ist3 = (uint64_t)Memory::KernelAllocate4KPages(8);

        for(unsigned i = 0; i < 8; i++){
            Memory::KernelMapVirtualMemory4K(Memory::AllocatePhysicalMemoryBlock(), tss->ist1 + 8 * PAGE_SIZE_4K, 1);
            Memory::KernelMapVirtualMemory4K(Memory::AllocatePhysicalMemoryBlock(), tss->ist2 + 8 * PAGE_SIZE_4K, 1);
            Memory::KernelMapVirtualMemory4K(Memory::AllocatePhysicalMemoryBlock(), tss->ist3 + 8 * PAGE_SIZE_4K, 1);
        }

        memset((void*)tss->ist1, 0, PAGE_SIZE_4K);
        memset((void*)tss->ist2, 0, PAGE_SIZE_4K);
        memset((void*)tss->ist3, 0, PAGE_SIZE_4K);

        tss->ist1 += PAGE_SIZE_4K * 8;
        tss->ist2 += PAGE_SIZE_4K * 8;
        tss->ist3 += PAGE_SIZE_4K * 8;

        asm volatile("mov %%rsp, %0" : "=r"(tss->rsp0));
            
        asm volatile("ltr %%ax" :: "a"(0x2B));
    }
}