/*- * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * William Jolitz. * * 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. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * * originally from: locore.s, by William F. Jolitz * * Substantially rewritten by David Greenman, Rod Grimes, * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp * and many others. */ #include "opt_bootp.h" #include "opt_nfsroot.h" #include "opt_pmap.h" #include <sys/reboot.h> #include <machine/asmacros.h> #include <machine/cputypes.h> #include <machine/psl.h> #include <machine/pmap.h> #include <machine/specialreg.h> #include "assym.inc" /* * Compiled KERNBASE location and the kernel load address, now identical. */ .globl kernbase .set kernbase,KERNBASE .globl kernload .set kernload,KERNLOAD /* * Globals */ .data ALIGN_DATA /* just to be sure */ .space 0x2000 /* space for tmpstk - temporary stack */ tmpstk: .globl bootinfo bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ .text /********************************************************************** * * This is where the bootblocks start us, set the ball rolling... * */ ENTRY(btext) /* Tell the bios to warmboot next time */ movw $0x1234,0x472 /* Set up a real frame in case the double return in newboot is executed. */ xorl %ebp,%ebp pushl %ebp movl %esp, %ebp /* Don't trust what the BIOS gives for eflags. */ pushl $PSL_KERNEL popfl /* * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap * to set %cs, %ds, %es and %ss. */ mov %ds, %ax mov %ax, %fs mov %ax, %gs /* * Clear the bss. Not all boot programs do it, and it is our job anyway. * * XXX we don't check that there is memory for our bss and page tables * before using it. * * Note: we must be careful to not overwrite an active gdt or idt. They * inactive from now until we switch to new ones, since we don't load any * more segment registers or permit interrupts until after the switch. */ movl $__bss_end,%ecx movl $__bss_start,%edi subl %edi,%ecx xorl %eax,%eax cld rep stosb call recover_bootinfo /* Get onto a stack that we can trust. */ /* * XXX this step is delayed in case recover_bootinfo needs to return via * the old stack, but it need not be, since recover_bootinfo actually * returns via the old frame. */ movl $tmpstk,%esp call identify_cpu call pmap_cold /* set up bootstrap stack */ movl proc0kstack,%eax /* location of in-kernel stack */ /* * Only use bottom page for init386(). init386() calculates the * PCB + FPU save area size and returns the true top of stack. */ leal PAGE_SIZE(%eax),%esp xorl %ebp,%ebp /* mark end of frames */ pushl physfree /* value of first for init386(first) */ call init386 /* wire 386 chip for unix operation */ /* * Clean up the stack in a way that db_numargs() understands, so * that backtraces in ddb don't underrun the stack. Traps for * inaccessible memory are more fatal than usual this early. */ addl $4,%esp /* Switch to true top of stack. */ movl %eax,%esp call mi_startup /* autoconfiguration, mountroot etc */ /* NOTREACHED */ addl $0,%esp /* for db_numargs() again */ /********************************************************************** * * Recover the bootinfo passed to us from the boot program * */ recover_bootinfo: /* * This code is called in different ways depending on what loaded * and started the kernel. This is used to detect how we get the * arguments from the other code and what we do with them. * * Old disk boot blocks: * (*btext)(howto, bootdev, cyloffset, esym); * [return address == 0, and can NOT be returned to] * [cyloffset was not supported by the FreeBSD boot code * and always passed in as 0] * [esym is also known as total in the boot code, and * was never properly supported by the FreeBSD boot code] * This code from 1.x/2.x doesn't supply now-required metadata and * likely will fail (we test for it to avoid dereferencing stack * garbage here). * * Old diskless netboot code: * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); * [return address != 0, and can NOT be returned to] * If we are being booted by this code it will NOT work, * so we are just going to halt if we find this case. * * New uniform boot code: * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) * [return address != 0, and can be returned to] * * There may seem to be a lot of wasted arguments in here, but * that is so the newer boot code can still load very old kernels * and old boot code can load new kernels. */ /* * The old style disk boot blocks fake a frame on the stack and did an * lret to get here. The frame on the stack has a return address of 0. * This style of boot (from 1.x / 2.x) almost certainly won't work, * since the kernel has required metadata since about 7.x or so and none * are present. */ cmpl $0,4(%ebp) je olddiskboot /* * We have some form of return address, so this is either the * old diskless netboot code, or the new uniform code. That can * be detected by looking at the 5th argument, if it is 0 * we are being booted by the new uniform boot code. */ cmpl $0,24(%ebp) je newboot /* * Seems we have been loaded by the old 1.x/2.x diskless boot code, we * don't stand a chance of running as the diskless structure changed * considerably between the two, so just halt. */ hlt /* * We have been loaded by the new uniform boot code. * Let's check the bootinfo version, and if we do not understand * it we return to the loader with a status of 1 to indicate this error */ newboot: movl 28(%ebp),%ebx /* &bootinfo.version */ movl BI_VERSION(%ebx),%eax cmpl $1,%eax /* We only understand version 1 */ je 1f testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ jne 1f movl $1,%eax /* Return status */ leave /* * XXX this returns to our caller's caller (as is required) since * we didn't set up a frame and our caller did. */ ret 1: /* * If we have a kernelname copy it in */ movl BI_KERNELNAME(%ebx),%esi cmpl $0,%esi je 2f /* No kernelname */ movl $MAXPATHLEN,%ecx /* Brute force!!! */ movl $kernelname,%edi cmpb $'/',(%esi) /* Make sure it starts with a slash */ je 1f movb $'/',(%edi) incl %edi decl %ecx 1: cld rep movsb 2: /* * Determine the size of the boot loader's copy of the bootinfo * struct. Copy min(our size, loader's size) into our bootinfo. * Incompatible with really old boot loaders from FreeBSD 1.x and 2.0. */ movl %ebx,%esi movl $bootinfo,%edi movl BI_SIZE(%ebx),%ecx cmpl $BOOTINFO_SIZE,%ecx jbe got_common_bi_size movl $BOOTINFO_SIZE,%ecx got_common_bi_size: cld rep movsb #ifdef NFS_ROOT #ifndef BOOTP_NFSV3 /* * If we have a nfs_diskless structure copy it in */ movl BI_NFS_DISKLESS(%ebx),%esi cmpl $0,%esi je olddiskboot movl $nfs_diskless,%edi movl $NFSDISKLESS_SIZE,%ecx cld rep movsb movl $nfs_diskless_valid,%edi movl $1,(%edi) #endif #endif /* * The old style disk boot. * (*btext)(howto, bootdev, cyloffset, esym); * Note that the newer boot code just falls into here to pick * up howto and bootdev, cyloffset and esym are no longer used */ olddiskboot: movl 8(%ebp),%eax movl %eax,boothowto movl 12(%ebp),%eax movl %eax,bootdev ret /********************************************************************** * * Identify the CPU and initialize anything special about it * */ ENTRY(identify_cpu) pushl %ebx /* Try to toggle alignment check flag; does not exist on 386. */ pushfl popl %eax movl %eax,%ecx orl $PSL_AC,%eax pushl %eax popfl pushfl popl %eax xorl %ecx,%eax andl $PSL_AC,%eax pushl %ecx popfl testl %eax,%eax jnz try486 /* NexGen CPU does not have alignment check flag. */ pushfl movl $0x5555, %eax xorl %edx, %edx movl $2, %ecx clc divl %ecx jz trynexgen popfl movl $CPU_386,cpu jmp 3f trynexgen: popfl movl $CPU_NX586,cpu movl $0x4778654e,cpu_vendor # store vendor string movl $0x72446e65,cpu_vendor+4 movl $0x6e657669,cpu_vendor+8 movl $0,cpu_vendor+12 jmp 3f try486: /* Try to toggle identification flag; does not exist on early 486s. */ pushfl popl %eax movl %eax,%ecx xorl $PSL_ID,%eax pushl %eax popfl pushfl popl %eax xorl %ecx,%eax andl $PSL_ID,%eax pushl %ecx popfl testl %eax,%eax jnz trycpuid movl $CPU_486,cpu /* * Check Cyrix CPU * Cyrix CPUs do not change the undefined flags following * execution of the divide instruction which divides 5 by 2. * * Note: CPUID is enabled on M2, so it passes another way. */ pushfl movl $0x5555, %eax xorl %edx, %edx movl $2, %ecx clc divl %ecx jnc trycyrix popfl jmp 3f /* You may use Intel CPU. */ trycyrix: popfl /* * IBM Bluelighting CPU also doesn't change the undefined flags. * Because IBM doesn't disclose the information for Bluelighting * CPU, we couldn't distinguish it from Cyrix's (including IBM * brand of Cyrix CPUs). */ movl $0x69727943,cpu_vendor # store vendor string movl $0x736e4978,cpu_vendor+4 movl $0x64616574,cpu_vendor+8 jmp 3f trycpuid: /* Use the `cpuid' instruction. */ xorl %eax,%eax cpuid # cpuid 0 movl %eax,cpu_high # highest capability movl %ebx,cpu_vendor # store vendor string movl %edx,cpu_vendor+4 movl %ecx,cpu_vendor+8 movb $0,cpu_vendor+12 movl $1,%eax cpuid # cpuid 1 movl %eax,cpu_id # store cpu_id movl %ebx,cpu_procinfo # store cpu_procinfo movl %edx,cpu_feature # store cpu_feature movl %ecx,cpu_feature2 # store cpu_feature2 rorl $8,%eax # extract family type andl $15,%eax cmpl $5,%eax jae 1f /* less than Pentium; must be 486 */ movl $CPU_486,cpu jmp 3f 1: /* a Pentium? */ cmpl $5,%eax jne 2f movl $CPU_586,cpu jmp 3f 2: /* Greater than Pentium...call it a Pentium Pro */ movl $CPU_686,cpu 3: popl %ebx ret END(identify_cpu) #ifdef XENHVM /* Xen Hypercall page */ .text .p2align PAGE_SHIFT, 0x90 /* Hypercall_page needs to be PAGE aligned */ ENTRY(hypercall_page) .skip 0x1000, 0x90 /* Fill with "nop"s */ #endif
