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Convert the short stub of real-mode code into 16-bit assembly.

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This commit is contained in:
John Baldwin 2000-05-24 02:20:34 +00:00
parent 8312b3f4f7
commit e1efa49a84
2 changed files with 22 additions and 22 deletions
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22
sys/boot/i386/btx/btxldr/btxldr.S
View File

@ -234,24 +234,24 @@ ifdef(`BTXLDR_VERBOSE',`
')
movl $start.8,%esi # Real mode stub
movl $MEM_STUB,%edi # Destination
movl $SIZ_STUB,%ecx # Size
movl $start.9-start.8,%ecx # Size
rep # Relocate
movsb # it
ljmp $SEL_RCODE,$MEM_STUB # To 16-bit code
start.8: xorl %eax,%eax # Data
.code16
start.8: xorw %ax,%ax # Data
movb $SEL_RDATA,%al # selector
movl %eax,%ss # Reload SS
movl %eax,%ds # Reset
movl %eax,%es # other
movl %eax,%fs # segment
movl %eax,%gs # limits
movw %ax,%ss # Reload SS
movw %ax,%ds # Reset
movw %ax,%es # other
movw %ax,%fs # segment
movw %ax,%gs # limits
movl %cr0,%eax # Switch to
decl %eax # real
decw %ax # real
movl %eax,%cr0 # mode
.byte 0xea # Jump to
.word MEM_ENTRY # BTX entry
.word 0x0 # point
ljmp $0,$MEM_ENTRY # Jump to BTX entry point
start.9:
.code32
#
# Output message [ESI] followed by EAX in hex.
#

22
sys/boot/i386/btx/btxldr/btxldr.s
View File

@ -234,24 +234,24 @@ ifdef(`BTXLDR_VERBOSE',`
')
movl $start.8,%esi # Real mode stub
movl $MEM_STUB,%edi # Destination
movl $SIZ_STUB,%ecx # Size
movl $start.9-start.8,%ecx # Size
rep # Relocate
movsb # it
ljmp $SEL_RCODE,$MEM_STUB # To 16-bit code
start.8: xorl %eax,%eax # Data
.code16
start.8: xorw %ax,%ax # Data
movb $SEL_RDATA,%al # selector
movl %eax,%ss # Reload SS
movl %eax,%ds # Reset
movl %eax,%es # other
movl %eax,%fs # segment
movl %eax,%gs # limits
movw %ax,%ss # Reload SS
movw %ax,%ds # Reset
movw %ax,%es # other
movw %ax,%fs # segment
movw %ax,%gs # limits
movl %cr0,%eax # Switch to
decl %eax # real
decw %ax # real
movl %eax,%cr0 # mode
.byte 0xea # Jump to
.word MEM_ENTRY # BTX entry
.word 0x0 # point
ljmp $0,$MEM_ENTRY # Jump to BTX entry point
start.9:
.code32
#
# Output message [ESI] followed by EAX in hex.
#