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Retire the support for using paging in BTX. It hasn't been used since

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before 4.0.

Submitted by:	kib
This commit is contained in:
jhb 2008-02-27 23:35:39 +00:00
parent 8ee71003bd
commit ac298b1543
2 changed files with 2 additions and 57 deletions
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4
sys/boot/i386/btx/btx/Makefile
View File

@ -5,10 +5,6 @@ INTERNALPROG=
NO_MAN=
SRCS= btx.S
.if defined(PAGING)
CFLAGS+=-DPAGING
.endif
.if defined(BOOT_BTX_NOHANG)
BOOT_BTX_FLAGS=0x1
.else

55
sys/boot/i386/btx/btx/btx.S
View File

@ -25,8 +25,7 @@
.set MEM_IDT,0x1e00 # IDT
.set MEM_TSS,0x1f98 # TSS
.set MEM_MAP,0x2000 # I/O bit map
.set MEM_DIR,0x4000 # Page directory
.set MEM_TBL,0x5000 # Page tables
.set MEM_TSS_END,0x3fff # Page directory
.set MEM_ORG,0x9000 # BTX code
.set MEM_USR,0xa000 # Start of user memory
/*
@ -88,7 +87,7 @@
.set _ESP0H,MEM_ESP0>>0x8 # Byte 1 of ESP0
.set _ESP1H,MEM_ESP1>>0x8 # Byte 1 of ESP1
.set _TSSIO,MEM_MAP-MEM_TSS # TSS I/O base
.set _TSSLM,MEM_DIR-MEM_TSS-1 # TSS limit
.set _TSSLM,MEM_TSS_END-MEM_TSS # TSS limit
.set _IDTLM,MEM_TSS-MEM_IDT-1 # IDT limit
/*
* Code segment.
@ -158,58 +157,15 @@ init.4: movb $_ESP0H,TSS_ESP0+1(%di) # Set ESP0
movb $SEL_SDATA,TSS_SS0(%di) # Set SS0
movb $_ESP1H,TSS_ESP1+1(%di) # Set ESP1
movb $_TSSIO,TSS_MAP(%di) # Set I/O bit map base
#ifdef PAGING
/*
* Create page directory.
*/
xor %edx,%edx # Page
mov $PAG_SIZ>>0x8,%dh # size
xor %eax,%eax # Zero
mov $MEM_DIR,%di # Page directory
mov $PAG_CNT>>0xa,%cl # Entries
mov $MEM_TBL|0x7,%ax # First entry
init.5: stosl # Write entry
add %dx,%ax # To next
loop init.5 # Till done
/*
* Create page tables.
*/
mov $MEM_TBL,%di # Page table
mov $PAG_CNT>>0x8,%ch # Entries
xor %ax,%ax # Start address
init.6: mov $0x7,%al # Set U:W:P flags
cmp btx_hdr+0x8,%cx # Standard user page?
jb init.7 # Yes
cmp $PAG_CNT-MEM_BTX>>0xc,%cx # BTX memory?
jae init.7 # No or first page
and $~0x2,%al # Clear W flag
cmp $PAG_CNT-MEM_USR>>0xc,%cx # User page zero?
jne init.7 # No
testb $0x80,btx_hdr+0x7 # Unmap it?
jz init.7 # No
and $~0x1,%al # Clear P flag
init.7: stosl # Set entry
add %edx,%eax # Next address
loop init.6 # Till done
#endif
/*
* Bring up the system.
*/
mov $0x2820,%bx # Set protected mode
callw setpic # IRQ offsets
lidt idtdesc # Set IDT
#ifdef PAGING
xor %eax,%eax # Set base
mov $MEM_DIR>>0x8,%ah # of page
mov %eax,%cr3 # directory
#endif
lgdt gdtdesc # Set GDT
mov %cr0,%eax # Switch to protected
#ifdef PAGING
or $0x80000001,%eax # mode and enable paging
#else
inc %ax # mode
#endif
mov %eax,%cr0 #
ljmp $SEL_SCODE,$init.8 # To 32-bit code
.code32
@ -854,13 +810,6 @@ intx30: cmpl $SYS_EXEC,%eax # Exec system call?
movl $MEM_USR,%eax # User base address
addl 0xc(%esp,1),%eax # Change to user
leal 0x4(%eax),%esp # stack
#ifdef PAGING
movl %cr0,%eax # Turn
andl $~0x80000000,%eax # off
movl %eax,%cr0 # paging
xorl %eax,%eax # Flush
movl %eax,%cr3 # TLB
#endif
popl %eax # Call
call *%eax # program
intx30.1: orb $0x1,%ss:btx_hdr+0x7 # Flag reboot