#include <arch/regs.h>
#include <arch/msr.h>

void arch_regs_firsttimesetup(arch_regs* regs, arch_extraregs* xregs){
	xregs->mxcsr = 0x1F80; // all exceptions masked
}

void arch_regs_saveextra(arch_extraregs* regs){
	// user gs was swapped
	regs->gsbase = rdmsr(MSR_KERNELGSBASE);
	regs->fsbase = rdmsr(MSR_FSBASE);	
	asm("fxsave (%%rax)" : : "a"(&regs->fx[0]));
	asm("stmxcsr (%%rax)" : : "a"(&regs->mxcsr));
}

void arch_regs_setupextra(arch_extraregs* regs){
	// gs will be swapped later
	wrmsr(MSR_KERNELGSBASE, regs->gsbase);
	wrmsr(MSR_FSBASE, regs->fsbase);
	asm("fxrstor (%%rax)" : : "a"(&regs->fx[0]));
	asm("ldmxcsr (%%rax)" : : "a"(&regs->mxcsr));
}

void arch_regs_setupkernel(arch_regs* regs, void* ip, void* stack, bool interrupts){
        regs->rip = ip;
        regs->rsp = stack;
        regs->cs = 0x28;
        regs->ds = 0x30;
        regs->es = 0x30;
        regs->fs = 0x30;
        regs->gs = 0x30;
        regs->ss = 0x30;
        regs->rflags = interrupts ? 0x200 : 0;	
}

void arch_regs_setupuser(arch_regs* regs, void* ip, void* stack, bool interrupts){
	regs->rip = ip;
	regs->rsp = stack;
	regs->cs = 0x38 | 3;
	regs->ds = 0x40 | 3;
        regs->es = 0x40 | 3;
        regs->fs = 0x40 | 3;
        regs->gs = 0x40 | 3;
        regs->ss = 0x40 | 3;
        regs->rflags = interrupts ? 0x200 : 0;

}