diff options
| author | rnordier <rnordier@FreeBSD.org> | 1999-02-25 16:27:41 +0000 |
|---|---|---|
| committer | rnordier <rnordier@FreeBSD.org> | 1999-02-25 16:27:41 +0000 |
| commit | a3fa9785d059a69334c6d4842a24d0e8300c8300 (patch) | |
| tree | 9c9c680c2bcb2c490cfc17f3a9847c61c84a266d /sys/boot/i386/btx | |
| parent | 9bdf1013f1c3598e9e319df65deb303e413a2c03 (diff) | |
| download | FreeBSD-src-a3fa9785d059a69334c6d4842a24d0e8300c8300.zip FreeBSD-src-a3fa9785d059a69334c6d4842a24d0e8300c8300.tar.gz | |
Emulate a V86 "movl %cr0,%eax" instruction.
Feedback and testing: Kurt Hopfensperger <kjhmdjd@ix.netcom.com>
Diffstat (limited to 'sys/boot/i386/btx')
| -rw-r--r-- | sys/boot/i386/btx/btx/btx.S | 38 | ||||
| -rw-r--r-- | sys/boot/i386/btx/btx/btx.s | 38 |
2 files changed, 52 insertions, 24 deletions
diff --git a/sys/boot/i386/btx/btx/btx.S b/sys/boot/i386/btx/btx/btx.S index d02cc87..29b9795 100644 --- a/sys/boot/i386/btx/btx/btx.S +++ b/sys/boot/i386/btx/btx/btx.S @@ -13,7 +13,7 @@ # purpose. # -# $Id: btx.s,v 1.8 1998/11/02 17:53:08 rnordier Exp $ +# $Id: btx.s,v 1.9 1999/01/22 13:07:17 rnordier Exp $ # # Memory layout. @@ -100,7 +100,7 @@ btx_hdr: .byte 0xeb # Machine ID .byte 0xe # Header size .ascii "BTX" # Magic .byte 0x1 # Major version - .byte 0x0 # Minor version + .byte 0x1 # Minor version .byte 0x0 # Flags .word PAG_CNT-MEM_ORG>>0xc # Paging control .word break-start # Text size @@ -459,9 +459,15 @@ v86mon.1: lodsb # Get opcode v86mon.2: cmpb $0xf4,%al # HLT? jne v86mon.3 # No cmpl $inthlt+0x1,%esi # Is inthlt? - jne v86mon.6 # No (ignore) + jne v86mon.7 # No (ignore) jmp intrtn # Return to user mode -v86mon.3: cmpb $0xfa,%al # CLI? +v86mon.3: cmpb $0xf,%al # Is + jne v86mon.4 # this + cmpb $0x20,(%esi) # a + jne v86mon.4 # MOV EAX,CR0 + cmpb $0xc0,0x1(%esi) # instruction? + je v86mov # Yes +v86mon.4: cmpb $0xfa,%al # CLI? je v86cli # Yes cmpb $0xfb,%al # STI? je v86sti # Yes @@ -481,25 +487,33 @@ v86mon.3: cmpb $0xfa,%al # CLI? popl %ebx # Restore popa # Restore jmp except # Handle exception -v86mon.4: movl %edx,0x30(%ebp) # Save V86 flags -v86mon.5: popl %edx # V86 SS adjustment +v86mon.5: movl %edx,0x30(%ebp) # Save V86 flags +v86mon.6: popl %edx # V86 SS adjustment subl %edx,%ebx # Save V86 movl %ebx,0x34(%ebp) # SP -v86mon.6: subl %edi,%esi # From linear +v86mon.7: subl %edi,%esi # From linear movl %esi,0x28(%ebp) # Save V86 IP popa # Restore leal 0x8(%esp,1),%esp # Discard int no, error iret # To V86 mode # +# Emulate MOV EAX,CR0. +# +v86mov: movl %cr0,%eax # CR0 to + movl %eax,0x1c(%ebp) # saved EAX + incl %esi # Adjust + incl %esi # IP + jmp v86mon.7 # Finish up +# # Emulate CLI. # v86cli: andb $~0x2,0x31(%ebp) # Clear IF - jmp v86mon.6 # Finish up + jmp v86mon.7 # Finish up # # Emulate STI. # v86sti: orb $0x2,0x31(%ebp) # Set IF - jmp v86mon.6 # Finish up + jmp v86mon.7 # Finish up # # Emulate PUSHF/PUSHFD. # @@ -508,7 +522,7 @@ v86pushf: subl %ecx,%ebx # Adjust SP je v86pushf.1 # Yes o16 # 16-bit v86pushf.1: movl %edx,(%ebx) # Save flags - jmp v86mon.5 # Finish up + jmp v86mon.6 # Finish up # # Emulate IRET/IRETD. # @@ -529,7 +543,7 @@ v86popf.1: movl (%ebx),%eax # Load flags andl $V86_FLG,%eax # Merge andl $~V86_FLG,%edx # the orl %eax,%edx # flags - jmp v86mon.4 # Finish up + jmp v86mon.5 # Finish up # # Emulate INT imm8. # @@ -546,7 +560,7 @@ v86intn: lodsb # Get int no movl %edi,0x2c(%ebp) # Save CS xorl %edi,%edi # No ESI adjustment andb $~0x3,%dh # Clear IF and TF - jmp v86mon.4 # Finish up + jmp v86mon.5 # Finish up # # Hardware interrupt jump table. # diff --git a/sys/boot/i386/btx/btx/btx.s b/sys/boot/i386/btx/btx/btx.s index d02cc87..29b9795 100644 --- a/sys/boot/i386/btx/btx/btx.s +++ b/sys/boot/i386/btx/btx/btx.s @@ -13,7 +13,7 @@ # purpose. # -# $Id: btx.s,v 1.8 1998/11/02 17:53:08 rnordier Exp $ +# $Id: btx.s,v 1.9 1999/01/22 13:07:17 rnordier Exp $ # # Memory layout. @@ -100,7 +100,7 @@ btx_hdr: .byte 0xeb # Machine ID .byte 0xe # Header size .ascii "BTX" # Magic .byte 0x1 # Major version - .byte 0x0 # Minor version + .byte 0x1 # Minor version .byte 0x0 # Flags .word PAG_CNT-MEM_ORG>>0xc # Paging control .word break-start # Text size @@ -459,9 +459,15 @@ v86mon.1: lodsb # Get opcode v86mon.2: cmpb $0xf4,%al # HLT? jne v86mon.3 # No cmpl $inthlt+0x1,%esi # Is inthlt? - jne v86mon.6 # No (ignore) + jne v86mon.7 # No (ignore) jmp intrtn # Return to user mode -v86mon.3: cmpb $0xfa,%al # CLI? +v86mon.3: cmpb $0xf,%al # Is + jne v86mon.4 # this + cmpb $0x20,(%esi) # a + jne v86mon.4 # MOV EAX,CR0 + cmpb $0xc0,0x1(%esi) # instruction? + je v86mov # Yes +v86mon.4: cmpb $0xfa,%al # CLI? je v86cli # Yes cmpb $0xfb,%al # STI? je v86sti # Yes @@ -481,25 +487,33 @@ v86mon.3: cmpb $0xfa,%al # CLI? popl %ebx # Restore popa # Restore jmp except # Handle exception -v86mon.4: movl %edx,0x30(%ebp) # Save V86 flags -v86mon.5: popl %edx # V86 SS adjustment +v86mon.5: movl %edx,0x30(%ebp) # Save V86 flags +v86mon.6: popl %edx # V86 SS adjustment subl %edx,%ebx # Save V86 movl %ebx,0x34(%ebp) # SP -v86mon.6: subl %edi,%esi # From linear +v86mon.7: subl %edi,%esi # From linear movl %esi,0x28(%ebp) # Save V86 IP popa # Restore leal 0x8(%esp,1),%esp # Discard int no, error iret # To V86 mode # +# Emulate MOV EAX,CR0. +# +v86mov: movl %cr0,%eax # CR0 to + movl %eax,0x1c(%ebp) # saved EAX + incl %esi # Adjust + incl %esi # IP + jmp v86mon.7 # Finish up +# # Emulate CLI. # v86cli: andb $~0x2,0x31(%ebp) # Clear IF - jmp v86mon.6 # Finish up + jmp v86mon.7 # Finish up # # Emulate STI. # v86sti: orb $0x2,0x31(%ebp) # Set IF - jmp v86mon.6 # Finish up + jmp v86mon.7 # Finish up # # Emulate PUSHF/PUSHFD. # @@ -508,7 +522,7 @@ v86pushf: subl %ecx,%ebx # Adjust SP je v86pushf.1 # Yes o16 # 16-bit v86pushf.1: movl %edx,(%ebx) # Save flags - jmp v86mon.5 # Finish up + jmp v86mon.6 # Finish up # # Emulate IRET/IRETD. # @@ -529,7 +543,7 @@ v86popf.1: movl (%ebx),%eax # Load flags andl $V86_FLG,%eax # Merge andl $~V86_FLG,%edx # the orl %eax,%edx # flags - jmp v86mon.4 # Finish up + jmp v86mon.5 # Finish up # # Emulate INT imm8. # @@ -546,7 +560,7 @@ v86intn: lodsb # Get int no movl %edi,0x2c(%ebp) # Save CS xorl %edi,%edi # No ESI adjustment andb $~0x3,%dh # Clear IF and TF - jmp v86mon.4 # Finish up + jmp v86mon.5 # Finish up # # Hardware interrupt jump table. # |
