8080: further fixes for the banking code

diff --git a/Kernel/lib/8080fixedbank-core.s b/Kernel/lib/8080fixedbank-core.s
index 52db9f0..549e1ff 100644 (file)
--- a/Kernel/lib/8080fixedbank-core.s
+++ b/Kernel/lib/8080fixedbank-core.s
@@ -19,22 +19,33 @@
 !      Switch a process out and run the next one
 !
 _platform_switchout:
+       push b
        lxi h,0
        push h                  ! Save a 0 argment
-       push b
+       lhld .retadr
+       push h
+       lhld .bcreg
+       push h
+       lhld .tmp1
+       push h
+       lhld .areg
+       push h
        dad sp
        shld U_DATA__U_SP       ! Save the sp for a switch in
        call map_process_always_di
        !
        !       Save the udata into process state
        !
+       !       FIXME: can we skip this if the process is defunct or would
+       !       it even make sense to defer it (with magic in swapout) ?
+       !
        lxi h,U_DATA
        lxi d,U_DATA_STASH
        call copy512            ! No ldir 8(
        ! Back to kernel
        call map_kernel_di
        call _getproc           ! Who goes next
-       push h
+       push d
        call _switchin          ! Run it
        ! Should never hit this
        call _platform_monitor
@@ -63,7 +74,7 @@ _switchin:
        dad d
 
        lxi sp,_swapstack
-       mov a,m
+       mov a,m                 ! A is now our bank
        ora a
        jnz not_swapped
        !
@@ -92,7 +103,10 @@ _switchin:
        !
 not_swapped:
        mov c,a
+       ! DE is the process to run, get the udata process into HL
        lhld U_DATA__U_PTAB
+       ! See if our udata is live - this is common, if we sleep and we are
+       ! the next to run for example.
        mov a,h
        cmp d
        jnz copyback
@@ -105,10 +119,12 @@ not_swapped:
 copyback:
        mov a,c
        call map_process_a
-       
+
+       push d
        lxi h,U_DATA_STASH
        lxi d,U_DATA
        call copy512
+       pop d
 
        lhld U_DATA__U_SP       ! A valid stack to map on
        sphl
@@ -136,7 +152,7 @@ skip_copyback:
        lxi d,P_TAB__P_PAGE_OFFSET
        dad d
        mov a,m
-       sta U_DATA__U_PTAB
+       sta U_DATA__U_PAGE
        lxi h,0
        shld _runticks
        lhld U_DATA__U_SP
@@ -144,8 +160,21 @@ skip_copyback:
        !
        !       Recover our parent frame pointer and return code
        !
-       pop b
+       !       FIXME: do we need to handle .fra .trapproc or .retadr1 ?
+       !       Q: .fra and longs ?
+       !       probably we do need to save block1-block3 (12 bytes)
+       !
+       pop h
+       shld .areg
+       pop h
+       mov l,a
+       sta .tmp1
        pop h
+       shld .bcreg
+       pop h
+       shld .retadr
+       pop d
+       pop b
        lda U_DATA__U_ININTERRUPT
        sta _int_disabled
        ora a
@@ -186,9 +215,18 @@ _dofork:
        mov l,a
        !
        ! We don't have any state to save but the pid and framepointer 
+       ! and (alas) a pile of compiler non-reentrant crap
        !
        push b
        push h
+       lhld .retadr
+       push h
+       lhld .bcreg
+       push h
+       lhld .tmp1
+       push h
+       lhld .areg
+       push h
        lxi h,0
        dad sp
        shld U_DATA__U_SP
@@ -205,7 +243,8 @@ _dofork:
 
        call map_process_always
        !
-       !       Clone the parent udata and stack into the child stash
+       !       Copy the parent udata and stack into the parent stash
+       !       The live udata becomes that of the child
        !
        lxi h,U_DATA
        lxi d,U_DATA_STASH
@@ -214,6 +253,10 @@ _dofork:
        call map_kernel
 
        pop h           ! Get rid of saved pid
+       pop h           ! and C runtime state
+       pop h
+       pop h
+       pop h
 
        !
        !       Manufacture the child udata state

diff --git a/Kernel/lib/8080fixedbank.s b/Kernel/lib/8080fixedbank.s
index 63832f4..a49ba8c 100644 (file)
--- a/Kernel/lib/8080fixedbank.s
+++ b/Kernel/lib/8080fixedbank.s
@@ -6,6 +6,17 @@
 !      Fast copy 512 bytes from H to D
 !
 copy512:
+       in 21
+       adi 48
+       out 1
+       mvi a,":"
+       out 1
+       call outhl
+       xchg
+       mvi a,"-"
+       out 1
+       call outhl
+       xchg
        mvi b,64
 copy8:
        mov a,m
@@ -42,4 +53,8 @@ copy8:
        inx d
        dcr b
        jnz copy8
+       mvi a,'='
+       out 1
+       lhld 0xe800
+       call outhl
        ret