Function init_6x86

freebsd/i386/i386/initcpu.c:304–375

* Cyrix 6x86 * * XXX - What should I do here? Please let me know. */

 * XXX - What should I do here?  Please let me know.
 */
static void
init_6x86(void)
{
	register_t saveintr;
	u_char	ccr3, ccr4;

	saveintr = intr_disable();

	load_cr0(rcr0() | CR0_CD | CR0_NW);
	wbinvd();

	/* Initialize CCR0. */
	write_cyrix_reg(CCR0, read_cyrix_reg(CCR0) | CCR0_NC1);

	/* Initialize CCR1. */
#ifdef CPU_CYRIX_NO_LOCK
	write_cyrix_reg(CCR1, read_cyrix_reg(CCR1) | CCR1_NO_LOCK);
#else
	write_cyrix_reg(CCR1, read_cyrix_reg(CCR1) & ~CCR1_NO_LOCK);
#endif

	/* Initialize CCR2. */
#ifdef CPU_SUSP_HLT
	write_cyrix_reg(CCR2, read_cyrix_reg(CCR2) | CCR2_SUSP_HLT);
#else
	write_cyrix_reg(CCR2, read_cyrix_reg(CCR2) & ~CCR2_SUSP_HLT);
#endif

	ccr3 = read_cyrix_reg(CCR3);
	write_cyrix_reg(CCR3, CCR3_MAPEN0);

	/* Initialize CCR4. */
	ccr4 = read_cyrix_reg(CCR4);
	ccr4 |= CCR4_DTE;
	ccr4 &= ~CCR4_IOMASK;
#ifdef CPU_IORT
	write_cyrix_reg(CCR4, ccr4 | (CPU_IORT & CCR4_IOMASK));
#else
	write_cyrix_reg(CCR4, ccr4 | 7);
#endif

	/* Initialize CCR5. */
#ifdef CPU_WT_ALLOC
	write_cyrix_reg(CCR5, read_cyrix_reg(CCR5) | CCR5_WT_ALLOC);
#endif

	/* Restore CCR3. */
	write_cyrix_reg(CCR3, ccr3);

	/* Unlock NW bit in CR0. */
	write_cyrix_reg(CCR2, read_cyrix_reg(CCR2) & ~CCR2_LOCK_NW);

	/*
	 * Earlier revision of the 6x86 CPU could crash the system if
	 * L1 cache is in write-back mode.
	 */
	if ((cyrix_did & 0xff00) > 0x1600)
		load_cr0(rcr0() & ~(CR0_CD | CR0_NW));	/* CD = 0 and NW = 0 */