/*- * Copyright (c) 2001 Takanori Watanabe <takawata@jp.freebsd.org> * Copyright (c) 2001 Mitsuru IWASAKI <iwasaki@jp.freebsd.org> * Copyright (c) 2003 Peter Wemm * Copyright (c) 2008-2012 Jung-uk Kim <jkim@FreeBSD.org> * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <machine/asmacros.h> #include <machine/specialreg.h> #include <x86/ppireg.h> #include <x86/timerreg.h> #include "assym.inc" /* * Resume entry point for real mode. * * If XFirmwareWakingVector is zero and FirmwareWakingVector is non-zero * in FACS, the BIOS enters here in real mode after POST with CS set to * (FirmwareWakingVector >> 4) and IP set to (FirmwareWakingVector & 0xf). * Depending on the previous sleep state, we may need to initialize more * of the system (i.e., S3 suspend-to-RAM vs. S4 suspend-to-disk). * * Note: If XFirmwareWakingVector is non-zero, it should disable address * translation/paging and interrupts, load all segment registers with * a flat 4 GB address space, and set EFLAGS.IF to zero. Currently * this mode is not supported by this code. */ .data /* So we can modify it */ ALIGN_TEXT .code16 wakeup_start: /* * Set up segment registers for real mode, a small stack for * any calls we make, and clear any flags. */ cli /* make sure no interrupts */ mov %cs, %ax /* copy %cs to %ds. Remember these */ mov %ax, %ds /* are offsets rather than selectors */ mov %ax, %ss movw $PAGE_SIZE, %sp xorw %ax, %ax pushw %ax popfw /* To debug resume hangs, beep the speaker if the user requested. */ testb $~0, resume_beep - wakeup_start jz 1f movb $0, resume_beep - wakeup_start /* Set PIC timer2 to beep. */ movb $(TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT), %al outb %al, $TIMER_MODE /* Turn on speaker. */ inb $IO_PPI, %al orb $PIT_SPKR, %al outb %al, $IO_PPI /* Set frequency. */ movw $0x4c0, %ax outb %al, $TIMER_CNTR2 shrw $8, %ax outb %al, $TIMER_CNTR2 1: /* Re-initialize video BIOS if the reset_video tunable is set. */ testb $~0, reset_video - wakeup_start jz 1f movb $0, reset_video - wakeup_start lcall $0xc000, $3 /* When we reach here, int 0x10 should be ready. Hide cursor. */ movb $0x01, %ah movb $0x20, %ch int $0x10 /* Re-start in case the previous BIOS call clobbers them. */ jmp wakeup_start 1: /* * Find relocation base and patch the gdt descript and ljmp targets */ xorl %ebx, %ebx mov %cs, %bx sall $4, %ebx /* %ebx is now our relocation base */ /* * Load the descriptor table pointer. We'll need it when running * in 16-bit protected mode. */ lgdtl bootgdtdesc - wakeup_start /* Enable protected mode */ movl $CR0_PE, %eax mov %eax, %cr0 /* * Now execute a far jump to turn on protected mode. This * causes the segment registers to turn into selectors and causes * %cs to be loaded from the gdt. * * The following instruction is: * ljmpl $bootcode32 - bootgdt, $wakeup_32 - wakeup_start * but gas cannot assemble that. And besides, we patch the targets * in early startup and its a little clearer what we are patching. */ wakeup_sw32: .byte 0x66 /* size override to 32 bits */ .byte 0xea /* opcode for far jump */ .long wakeup_32 - wakeup_start /* offset in segment */ .word bootcode32 - bootgdt /* index in gdt for 32 bit code */ /* * At this point, we are running in 32 bit legacy protected mode. */ ALIGN_TEXT .code32 wakeup_32: mov $bootdata32 - bootgdt, %eax mov %ax, %ds /* * Turn on the PAE bit and optionally the LA57 bit for when paging * is later enabled. */ mov %cr4, %eax orl $CR4_PAE, %eax leal wakeup_pagetables - wakeup_start(%ebx), %ecx movl (%ecx), %ecx testl $0x1, %ecx je 1f orl $CR4_LA57, %eax 1: mov %eax, %cr4 /* * Enable EFER.LME so that we get long mode when all the prereqs are * in place. In this case, it turns on when CR0_PG is finally enabled. * Also it picks up a few other EFER bits that we'll use need we're * here, like SYSCALL and NX enable. */ movl $MSR_EFER, %ecx movl wakeup_efer - wakeup_start(%ebx), %eax movl wakeup_efer + 4 - wakeup_start(%ebx), %edx wrmsr /* * Point to the embedded page tables for startup. Note that this * only gets accessed after we're actually in 64 bit mode, however * we can only set the bottom 32 bits of %cr3 in this state. This * means we are required to use a temporary page table that is below * the 4GB limit. %ebx is still our relocation base. We could just * subtract 3 * PAGE_SIZE, but that would be too easy. */ leal wakeup_pagetables - wakeup_start(%ebx), %eax movl (%eax), %eax andl $~0x1, %eax mov %eax, %cr3 /* * Finally, switch to long bit mode by enabling paging. We have * to be very careful here because all the segmentation disappears * out from underneath us. The spec says we can depend on the * subsequent pipelined branch to execute, but *only if* everything * is still identity mapped. If any mappings change, the pipeline * will flush. */ mov %cr0, %eax orl $CR0_PG, %eax mov %eax, %cr0 /* * At this point paging is enabled, and we are in "compatibility" mode. * We do another far jump to reload %cs with the 64 bit selector. * %cr3 points to a 4-level page table page. * We cannot yet jump all the way to the kernel because we can only * specify a 32 bit linear address. So, yet another trampoline. * * The following instruction is: * ljmp $bootcode64 - bootgdt, $wakeup_64 - wakeup_start * but gas cannot assemble that. And besides, we patch the targets * in early startup and its a little clearer what we are patching. */ wakeup_sw64: .byte 0xea /* opcode for far jump */ .long wakeup_64 - wakeup_start /* offset in segment */ .word bootcode64 - bootgdt /* index in gdt for 64 bit code */ /* * Yeehar! We're running in 64-bit mode! We can mostly ignore our * segment registers, and get on with it. * Note that we are running at the correct virtual address, but with * a 1:1 1GB mirrored mapping over entire address space. We had better * switch to a real %cr3 promptly so that we can get to the direct map * space. Remember that jmp is relative and that we've been relocated, * so use an indirect jump. */ ALIGN_TEXT .code64 wakeup_64: mov $bootdata64 - bootgdt, %eax mov %ax, %ds /* Restore arguments. */ movq wakeup_pcb - wakeup_start(%rbx), %rdi movq wakeup_ret - wakeup_start(%rbx), %rax /* Restore GDT. */ lgdt wakeup_gdt - wakeup_start(%rbx) /* Jump to return address. */ jmp *%rax .data resume_beep: .byte 0 reset_video: .byte 0 ALIGN_DATA bootgdt: .long 0x00000000 .long 0x00000000 .long 0x00000000 .long 0x00000000 .long 0x00000000 .long 0x00000000 .long 0x00000000 .long 0x00000000 bootcode64: .long 0x0000ffff .long 0x00af9b00 bootdata64: .long 0x0000ffff .long 0x00af9300 bootcode32: .long 0x0000ffff .long 0x00cf9b00 bootdata32: .long 0x0000ffff .long 0x00cf9300 bootgdtend: wakeup_pagetables: .long 0 bootgdtdesc: .word bootgdtend - bootgdt /* Length */ .long bootgdt - wakeup_start /* Offset plus %ds << 4 */ ALIGN_DATA wakeup_pcb: .quad 0 wakeup_ret: .quad 0 wakeup_efer: .quad 0 wakeup_gdt: .word 0 .quad 0 dummy:
