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[src/sommerfeld_i386mp_1]: src/sys/arch/i386/bioscall Fix warnings about regi...
details: https://anonhg.NetBSD.org/src/rev/09258297e6c5
branches: sommerfeld_i386mp_1
changeset: 482464:09258297e6c5
user: christos <christos%NetBSD.org@localhost>
date: Fri Dec 14 20:30:11 2001 +0000
description:
Fix warnings about register prefixes caused by the new toolchain.
diffstat:
sys/arch/i386/bioscall/biostramp.S | 347 +++++++++++++++++++++++++++++++++++++
1 files changed, 347 insertions(+), 0 deletions(-)
diffs (truncated from 351 to 300 lines):
diff -r 70cc4f2e0b7b -r 09258297e6c5 sys/arch/i386/bioscall/biostramp.S
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/arch/i386/bioscall/biostramp.S Fri Dec 14 20:30:11 2001 +0000
@@ -0,0 +1,347 @@
+/* $NetBSD: biostramp.S,v 1.10.2.2 2001/12/14 20:30:11 christos Exp $ */
+
+/*-
+ * Copyright (c) 1996 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by John Kohl.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the NetBSD
+ * Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+/*
+ * biostramp.S: provide a means for NetBSD to call BIOS interrupts
+ * by switching to real mode, calling it, and switching
+ * back to protected & paging mode.
+ */
+
+/*
+ * Micro$haft's book on i386/i486 programming says you should do the following
+ * to return to real mode from protected mode:
+ *
+ * 1) disable paging, by jumping to code with identical virtual and physical
+ * addresses, clearing PG in CR0, and zeroing CR3 (PDBR).
+ *
+ * 2) segment descriptors must be byte-granular with limit 64k-1, def32 = 0,
+ * (i.e. 16-bit data accesses and/or 80286 instructions)
+ * CS must be executable; DS,ES,FS,GS should be writable
+ *
+ * 3) disable interrupts, load IDTR with original value (base 0, limit 1023)
+ *
+ * 4) clear PE in CR0, execute FAR jump to load CS.
+ *
+ * 5) load SP, and off you go
+ *
+ */
+
+#include "assym.h"
+
+#include <i386/include/param.h>
+#include <i386/include/specialreg.h>
+#include <i386/include/segments.h>
+#include <i386/include/apmvar.h>
+#include <i386/include/psl.h>
+#include <i386/include/asm.h>
+
+#define addr32 .byte 0x67
+#define data32 .byte 0x66
+
+ .set MYBASE,NBPG
+ .set MYSCRATCH,NBPG+NBPG
+ .set CR3_ADDR,(MYSCRATCH-4)
+ .set IDTR_SAVE_ADDR,CR3_ADDR-6
+ .set GDTR_SAVE_ADDR,IDTR_SAVE_ADDR-6
+ .set GDTR_LOCAL_ADDR,GDTR_SAVE_ADDR-6
+ .set STACK_PTR_ADDR,GDTR_LOCAL_ADDR-4
+ .set BASE_PTR_ADDR,STACK_PTR_ADDR-4
+ .set FUNCTION_ADDR,(BASE_PTR_ADDR-2)
+ .set GDT_COPY_ADDR,(FUNCTION_ADDR-NGDT*8)
+ .set EAX_REGADDR,(GDT_COPY_ADDR-4)
+ .set EBX_REGADDR,(EAX_REGADDR-4)
+ .set ECX_REGADDR,(EBX_REGADDR-4)
+ .set EDX_REGADDR,(ECX_REGADDR-4)
+ .set ESI_REGADDR,(EDX_REGADDR-4)
+ .set EDI_REGADDR,(ESI_REGADDR-4)
+ .set EFLAGS_REGADDR,(EDI_REGADDR-4)
+ .set ES_REGADDR, (EFLAGS_REGADDR-4)
+ .set ENDREGADDR,(ES_REGADDR-4)
+
+ .set REALSTACK,ENDREGADDR-20 # leave a red zone?
+
+#define COPY_FLAGS (PSL_C|PSL_PF|PSL_AF|PSL_Z|PSL_N|PSL_D|PSL_V)
+
+/*
+ * do_bios_call(int function, struct bioscall *regs)
+ */
+
+ENTRY(do_bios_call)
+ pushl %ebp
+ movl %esp,%ebp /* set up frame ptr */
+ pushl %esi
+ pushl %edi
+ pushl %ebx
+ pushl %ds
+ pushl %es
+ pushl %fs
+ pushl %gs
+
+ # copy data to where the real-mode hook can handle it
+ movl 8(%ebp),%eax
+ movw %ax,FUNCTION_ADDR
+ movl 12(%ebp),%ebx
+ movl BIOSCALLREG_EAX(%ebx),%eax
+ movl %eax,EAX_REGADDR
+ movl BIOSCALLREG_EBX(%ebx),%eax
+ movl %eax,EBX_REGADDR
+ movl BIOSCALLREG_ECX(%ebx),%eax
+ movl %eax,ECX_REGADDR
+ movl BIOSCALLREG_EDX(%ebx),%eax
+ movl %eax,EDX_REGADDR
+ movl BIOSCALLREG_ESI(%ebx),%eax
+ movl %eax,ESI_REGADDR
+ movl BIOSCALLREG_EDI(%ebx),%eax
+ movl %eax,EDI_REGADDR
+ # merge current flags with certain provided flags
+ movl BIOSCALLREG_EFLAGS(%ebx),%ecx
+ pushfl
+ popl %eax
+ andl $~(COPY_FLAGS|PSL_I),%eax
+ andl $COPY_FLAGS,%ecx
+ orl %ecx,%eax
+ movl %eax,EFLAGS_REGADDR
+ movl $0, ES_REGADDR
+
+ # save flags, disable interrupts, do real mode stuff
+ pushfl
+
+ # save GDT
+ sgdt GDTR_SAVE_ADDR
+
+ # copy the GDT to local area
+ movl GDTR_SAVE_ADDR+2,%esi
+ movl $GDT_COPY_ADDR,%edi
+ movl $(NGDT*8),%ecx
+ cld
+ rep
+ movsb
+ movw $(NGDT*8)-1,GDTR_LOCAL_ADDR
+ movl $GDT_COPY_ADDR,GDTR_LOCAL_ADDR+2
+
+ # install GDT copy
+ lgdt GDTR_LOCAL_ADDR
+
+ cli
+
+ # save IDT
+ sidt IDTR_SAVE_ADDR
+
+ # set up new stack: save old ones, create new segs
+ movl %esp,STACK_PTR_ADDR
+ movl %ebp,BASE_PTR_ADDR
+ movl $REALSTACK,%esp
+ movl $0,%ebp # leave no trace, there is none.
+
+ # save CR3
+ movl %cr3,%eax
+ movl %eax,CR3_ADDR
+
+ # turn off paging
+ movl %cr0,%eax
+ andl $~(CR0_PG),%eax
+ movl %eax,%cr0
+
+ # flush TLB, drop PDBR
+ xorl %eax,%eax
+ movl %eax,%cr3
+
+ ## load 16-bit segment descriptors
+ movw $GSEL(GBIOSDATA_SEL,SEL_KPL),%bx
+ movw %bx,%ds
+ movw %bx,%es
+ movw %bx,%fs
+ movw %bx,%gs
+
+ ljmp $GSEL(GBIOSCODE_SEL,SEL_KPL),$x16+MYBASE
+
+x16:
+ # turn off protected mode--yikes!
+ mov %cr0,%eax
+ data32
+ and $~CR0_PE,%eax
+ mov %eax,%cr0
+
+ # need inter-segment jump to reload real-mode CS
+ data32
+ ljmp $(MYBASE>>4),$xreal
+
+xreal: # really in real mode now
+ # set up segment selectors. Note: everything is now relative
+ # to zero-base in this file, except %ss.
+ # data items in our scratch area need to reflect MYADDR
+ xorl %eax,%eax
+ movw %ax,%ss
+
+ movw %cs,%ax
+ movw %ax,%es
+ movw %ax,%fs
+ movw %ax,%gs
+ movw %ax,%ds
+
+ ## load IDT, now that we are here.
+ addr32
+ lidt IDT_bios
+
+ # Don't forget that we're in real mode, with 16-bit default data.
+ # all these movl's are really movw's, and movw's are movl's!
+ addr32
+ movw EDI_REGADDR-MYBASE,%di
+ addr32
+ movw ESI_REGADDR-MYBASE,%si
+ addr32
+ movw EDX_REGADDR-MYBASE,%dx
+ addr32
+ movw ECX_REGADDR-MYBASE,%cx
+ addr32
+ movw EBX_REGADDR-MYBASE,%bx
+ addr32
+ movb FUNCTION_ADDR-MYBASE,%al
+ addr32
+ movb %al,intaddr+1 # self modifying code, yuck. no indirect interrupt instruction!
+ # long jump to flush processor cache to reflect code modification
+ data32
+ ljmp $(MYBASE>>4),$flushit
+flushit:
+ addr32
+ movw EFLAGS_REGADDR-MYBASE,%ax
+ pushl %eax
+ popfl
+ addr32
+ movw EAX_REGADDR-MYBASE,%ax
+
+intaddr:
+ int $0xff
+
+ # save results
+ pushf
+ addr32
+ movw %ax,EAX_REGADDR-MYBASE
+ addr32
+ movw %bx,EBX_REGADDR-MYBASE
+ addr32
+ movw %cx,ECX_REGADDR-MYBASE
+ addr32
+ movw %dx,EDX_REGADDR-MYBASE
+ addr32
+ movw %si,ESI_REGADDR-MYBASE
+ addr32
+ movw %di,EDI_REGADDR-MYBASE
+ pop %ax
+ addr32
+ movw %ax,EFLAGS_REGADDR-MYBASE
+ addr32
+ movw %es,ES_REGADDR-MYBASE
+
+ # and return to protected mode
+ cli # just to be sure
+
+ mov %cr0,%eax
+ data32
+ or $CR0_PE,%eax
+ mov %eax,%cr0
+
+ # long jump to 32-bit code segment
+ data32
+ ljmp $GSEL(GCODE_SEL,SEL_KPL),$x32+MYBASE
+x32:
+ #back in 32-bit mode/protected mode (but not paging yet).
+ # Reload the segment registers & IDT
+
+ movw $GSEL(GDATA_SEL,SEL_KPL),%bx
+ movw %bx,%ds
+ movw %bx,%ss
+ movw %bx,%es
+
+ # reload PDBR
+ movl CR3_ADDR,%eax
+ movl %eax,%cr3
+ movl %cr0,%eax
+ orl $CR0_PG,%eax
+ movl %eax,%cr0
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