cpu.cpp

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//
// Created on 5/19/20.
//

#include <common.h>
#include <utilities.h>
#include <kprintf.h>
#include <registers.h>

namespace INIT
{
    void SSE()
    {
        asm volatile (
        "mov %%cr0, %%eax\n"
        "orl %0, %%eax\n"
        "andl %1, %%eax\n"
        "mov %%eax, %%cr0\n"
        "mov %%cr4, %%eax\n"
        "orl %2, %%eax\n"
        "orl %3, %%eax\n"
        "mov %%eax, %%cr4\n"
        : // no output
        : "n"(DWord<CR0::MP>()),
          "n"(~DWord<CR0::EM>()),
          "n"(DWord<CR4::OSFXSR>()),
          "n"(DWord<CR4::OSXMMEXCPT>())
        );

        kassert(ReadCR0() & DWord<CR0::MP>(), "MP bit of cr0 must be set for SSE support\n");
        kassert(~(ReadCR0() & DWord<CR0::EM>()), "EM bit of cr0 must be disabled for SSE support\n");
        kassert(ReadCR4() & (DWord<CR4::OSFXSR>() | DWord<CR4::OSXMMEXCPT>()));
    }
} // namespace INIT