--- /dev/null
+;
+; Generic handling for single process in memory Z80 systems.
+;
+; This code could really do with some optimizing.
+;
+ .module tricks
+
+ .globl _ptab_alloc
+ .globl _newproc
+ .globl _chksigs
+ .globl _getproc
+ .globl _platform_monitor
+ .globl trap_illegal
+ .globl _platform_switchout
+ .globl _switchin
+ .globl _doexec
+ .globl _dofork
+ .globl _runticks
+ .globl unix_syscall_entry
+ .globl interrupt_handler
+ .globl _swapper
+ .globl _swapout
+
+ ; imported debug symbols
+ .globl outstring, outde, outhl, outbc, outnewline, outchar, outcharhex
+
+ .include "kernel.def"
+ .include "../kernel.def"
+
+ .area _COMMONMEM
+
+; Switchout switches out the current process, finds another that is READY,
+; possibly the same process, and switches it in. When a process is
+; restarted after calling switchout, it thinks it has just returned
+; from switchout().
+;
+; This function can have no arguments or auto variables.
+_platform_switchout:
+ di
+ ; save machine state
+
+ ld hl, #0 ; return code set here is ignored, but _switchin can
+ ; return from either _switchout OR _dofork, so they must both write
+ ; U_DATA__U_SP with the following on the stack:
+ push hl ; return code
+ push ix
+ push iy
+ ld (U_DATA__U_SP), sp ; this is where the SP is restored in _switchin
+
+ ; find another process to run (may select this one again)
+ call _getproc
+
+ push hl
+ call _switchin
+
+ ; we should never get here
+ call _platform_monitor
+
+badswitchmsg: .ascii "_switchin: FAIL"
+ .db 13, 10, 0
+swapped: .ascii "_switchin: SWAPPED"
+ .db 13, 10, 0
+
+_switchin:
+ di
+ pop bc ; return address
+ pop de ; new process pointer
+;
+; FIXME: do we actually *need* to restore the stack !
+;
+ push de ; restore stack
+ push bc ; restore stack
+
+ push de
+ ld hl, #P_TAB__P_PAGE_OFFSET
+ add hl, de ; process ptr
+ pop de
+
+ ld a, (hl)
+
+ or a
+ jr nz, not_swapped
+ ;
+ ; We are still on the departing processes stack, which is
+ ; fine for now.
+ ;
+ ld sp, #_swapstack
+ ;
+ ; The process we are switching from is not resident. In
+ ; practice that means it exited. We don't need to write
+ ; it back out as it's dead.
+ ;
+ ld ix,(U_DATA__U_PTAB)
+ ld a,P_TAB__P_PAGE_OFFSET(ix)
+
+ or a
+ jr z, not_resident
+ ;
+ ; DE = process we are switching to
+ ;
+ push de ; save process
+ ; We will always swap out the current process
+ ld hl, (U_DATA__U_PTAB)
+ push hl
+ call _swapout
+ pop hl
+ pop de ; process to swap to
+not_resident:
+ push de ; called function may modify on stack arg so make
+ push de ; two copies
+ call _swapper
+ pop de
+ pop de
+
+not_swapped:
+ ; check u_data->u_ptab matches what we wanted
+ ld hl, (U_DATA__U_PTAB) ; u_data->u_ptab
+ or a ; clear carry flag
+ sbc hl, de ; subtract, result will be zero if DE==IX
+ jr nz, switchinfail
+
+ ; wants optimising up a bit
+ ld ix, (U_DATA__U_PTAB)
+ ; next_process->p_status = P_RUNNING
+ ld P_TAB__P_STATUS_OFFSET(ix), #P_RUNNING
+
+ ; Fix the moved page pointers
+ ; Just do one byte as that is all we use on this platform
+ ld a, P_TAB__P_PAGE_OFFSET(ix)
+ ld (U_DATA__U_PAGE), a
+ ; runticks = 0
+ ld hl, #0
+ ld (_runticks), hl
+
+ ; restore machine state -- note we may be returning from either
+ ; _switchout or _dofork
+ ld sp, (U_DATA__U_SP)
+
+ pop iy
+ pop ix
+ pop hl ; return code
+
+ ; enable interrupts, if the ISR isn't already running
+ ld a, (U_DATA__U_ININTERRUPT)
+ or a
+ ret nz ; in ISR, leave interrupts off
+ ei
+ ret ; return with interrupts on
+
+switchinfail:
+ call outhl
+ ld hl, #badswitchmsg
+ call outstring
+ ; something went wrong and we didn't switch in what we asked for
+ jp _platform_monitor
+
+fork_proc_ptr: .dw 0 ; (C type is struct p_tab *) -- address of child process p_tab entry
+
+;
+; Called from _fork. We are in a syscall, the uarea is live as the
+; parent uarea. The kernel is the mapped object.
+;
+_dofork:
+ ; always disconnect the vehicle battery before performing maintenance
+ di ; should already be the case ... belt and braces.
+
+ pop de ; return address
+ pop hl ; new process p_tab*
+ push hl
+ push de
+
+ ld (fork_proc_ptr), hl
+
+ ; prepare return value in parent process -- HL = p->p_pid;
+ ld de, #P_TAB__P_PID_OFFSET
+ add hl, de
+ ld a, (hl)
+ inc hl
+ ld h, (hl)
+ ld l, a
+
+ ; Save the stack pointer and critical registers.
+ ; When this process (the parent) is switched back in, it will be as if
+ ; it returns with the value of the child's pid.
+ push hl ; HL still has p->p_pid from above, the return value in the parent
+ push ix
+ push iy
+
+ ; save kernel stack pointer -- when it comes back in the parent we'll be in
+ ; _switchin which will immediately return (appearing to be _dofork()
+ ; returning) and with HL (ie return code) containing the child PID.
+ ; Hurray.
+ ld (U_DATA__U_SP), sp
+
+ ; now we're in a safe state for _switchin to return in the parent
+ ; process.
+
+ ld hl, (U_DATA__U_PTAB)
+ push hl
+ call _swapout
+ pop hl
+
+ ; now the copy operation is complete we can get rid of the stuff
+ ; _switchin will be expecting from our copy of the stack.
+ pop bc
+ pop bc
+ pop bc
+
+ ; Make a new process table entry, etc.
+ ld hl, (fork_proc_ptr)
+ push hl
+ call _newproc
+ pop bc
+
+ ; runticks = 0;
+ ld hl, #0
+ ld (_runticks), hl
+ ; in the child process, fork() returns zero.
+ ;
+ ; And we exit, with the kernel mapped, the child now being deemed
+ ; to be the live uarea. The parent is frozen in time and space as
+ ; if it had done a switchout().
+ ret
+;
+; We can keep a stack in common because we will complete our
+; use of it before we switch common block. In this case we have
+; a true common so it's even easier.
+;
+ .ds 128
+_swapstack:
/* Profil syscall support (not yet complete) */
#undef CONFIG_PROFIL
/* Multiple processes in memory at once */
-#define CONFIG_MULTI
+#undef CONFIG_MULTI
/* Single tasking */
#undef CONFIG_SINGLETASK
/* Video terminal, not a serial tty */
- .module tricks
-
- .globl _ptab_alloc
- .globl _newproc
- .globl _chksigs
- .globl _getproc
- .globl _platform_monitor
- .globl trap_illegal
- .globl _platform_switchout
- .globl _switchin
- .globl _doexec
- .globl _dofork
- .globl _runticks
- .globl unix_syscall_entry
- .globl interrupt_handler
- .globl _swapper
- .globl _swapout
-
- ; imported debug symbols
- .globl outstring, outde, outhl, outbc, outnewline, outchar, outcharhex
-
.include "kernel.def"
.include "../kernel.def"
- .area _COMMONMEM
-
-; Switchout switches out the current process, finds another that is READY,
-; possibly the same process, and switches it in. When a process is
-; restarted after calling switchout, it thinks it has just returned
-; from switchout().
-;
-; This function can have no arguments or auto variables.
-_platform_switchout:
- di
- ; save machine state
-
- ld hl, #0 ; return code set here is ignored, but _switchin can
- ; return from either _switchout OR _dofork, so they must both write
- ; U_DATA__U_SP with the following on the stack:
- push hl ; return code
- push ix
- push iy
- ld (U_DATA__U_SP), sp ; this is where the SP is restored in _switchin
-
- ; find another process to run (may select this one again)
- call _getproc
-
- push hl
- call _switchin
-
- ; we should never get here
- call _platform_monitor
-
-badswitchmsg: .ascii "_switchin: FAIL"
- .db 13, 10, 0
-swapped: .ascii "_switchin: SWAPPED"
- .db 13, 10, 0
-
-_switchin:
- di
- pop bc ; return address
- pop de ; new process pointer
-;
-; FIXME: do we actually *need* to restore the stack !
-;
- push de ; restore stack
- push bc ; restore stack
-
- push de
- ld hl, #P_TAB__P_PAGE_OFFSET
- add hl, de ; process ptr
- pop de
-
- ld a, (hl)
-
- or a
- jr nz, not_swapped
-
- ;
- ; We are still on the departing processes stack, which is
- ; fine for now.
- ;
- ld sp, #_swapstack
- push hl
- ; We will always swap out the current process
- ld hl, (U_DATA__U_PTAB)
- push hl
- call _swapout
- pop hl
- pop hl
- push de
- call _swapper
- pop de
- pop hl
- ld a, (hl)
-
-not_swapped:
- ; check u_data->u_ptab matches what we wanted
- ld hl, (U_DATA__U_PTAB) ; u_data->u_ptab
- or a ; clear carry flag
- sbc hl, de ; subtract, result will be zero if DE==IX
- jr nz, switchinfail
-
- ; wants optimising up a bit
- ld ix, (U_DATA__U_PTAB)
- ; next_process->p_status = P_RUNNING
- ld P_TAB__P_STATUS_OFFSET(ix), #P_RUNNING
-
- ; Fix the moved page pointers
- ; Just do one byte as that is all we use on this platform
- ld a, P_TAB__P_PAGE_OFFSET(ix)
- ld (U_DATA__U_PAGE), a
- ; runticks = 0
- ld hl, #0
- ld (_runticks), hl
-
- ; restore machine state -- note we may be returning from either
- ; _switchout or _dofork
- ld sp, (U_DATA__U_SP)
-
- pop iy
- pop ix
- pop hl ; return code
-
- ; enable interrupts, if the ISR isn't already running
- ld a, (U_DATA__U_ININTERRUPT)
- or a
- ret nz ; in ISR, leave interrupts off
- ei
- ret ; return with interrupts on
-
-switchinfail:
- call outhl
- ld hl, #badswitchmsg
- call outstring
- ; something went wrong and we didn't switch in what we asked for
- jp _platform_monitor
-
-fork_proc_ptr: .dw 0 ; (C type is struct p_tab *) -- address of child process p_tab entry
-
-;
-; Called from _fork. We are in a syscall, the uarea is live as the
-; parent uarea. The kernel is the mapped object.
-;
-_dofork:
- ; always disconnect the vehicle battery before performing maintenance
- di ; should already be the case ... belt and braces.
-
- pop de ; return address
- pop hl ; new process p_tab*
- push hl
- push de
-
- ld (fork_proc_ptr), hl
-
- ; prepare return value in parent process -- HL = p->p_pid;
- ld de, #P_TAB__P_PID_OFFSET
- add hl, de
- ld a, (hl)
- inc hl
- ld h, (hl)
- ld l, a
-
- ; Save the stack pointer and critical registers.
- ; When this process (the parent) is switched back in, it will be as if
- ; it returns with the value of the child's pid.
- push hl ; HL still has p->p_pid from above, the return value in the parent
- push ix
- push iy
-
- ; save kernel stack pointer -- when it comes back in the parent we'll be in
- ; _switchin which will immediately return (appearing to be _dofork()
- ; returning) and with HL (ie return code) containing the child PID.
- ; Hurray.
- ld (U_DATA__U_SP), sp
-
- ; now we're in a safe state for _switchin to return in the parent
- ; process.
-
- ld hl, (U_DATA__U_PTAB)
- push hl
- call _swapout
- pop hl
-
- ; now the copy operation is complete we can get rid of the stuff
- ; _switchin will be expecting from our copy of the stack.
- pop bc
- pop bc
- pop bc
-
- ; Make a new process table entry, etc.
- ld hl, (fork_proc_ptr)
- push hl
- call _newproc
- pop bc
+ .include "../lib/z80single.s"
- ; runticks = 0;
- ld hl, #0
- ld (_runticks), hl
- ; in the child process, fork() returns zero.
- ;
- ; And we exit, with the kernel mapped, the child now being deemed
- ; to be the live uarea. The parent is frozen in time and space as
- ; if it had done a switchout().
- ret
-;
-; We can keep a stack in common because we will complete our
-; use of it before we switch common block. In this case we have
-; a true common so it's even easier.
-;
- .ds 128
-_swapstack:
-; 2013-12-21 William R Sowerbutts
-
- .module tricks
-
- .globl _ptab_alloc
- .globl _newproc
- .globl _chksigs
- .globl _getproc
- .globl _platform_monitor
- .globl trap_illegal
- .globl _platform_switchout
- .globl _switchin
- .globl _doexec
- .globl _dofork
- .globl _runticks
- .globl unix_syscall_entry
- .globl interrupt_handler
- .globl _swapper
- .globl _swapout
- .globl _curbank
- .globl bank_switch_a
-
- ; imported debug symbols
- .globl outstring, outde, outhl, outbc, outnewline, outchar, outcharhex
-
.include "kernel.def"
.include "../kernel.def"
- .area _COMMONMEM
-
-; Switchout switches out the current process, finds another that is READY,
-; possibly the same process, and switches it in. When a process is
-; restarted after calling switchout, it thinks it has just returned
-; from switchout().
-;
-; This function can have no arguments or auto variables.
-_platform_switchout:
- di
- ; save machine state
-
- ld hl, #0 ; return code set here is ignored, but _switchin can
- ; return from either _switchout OR _dofork, so they must both write
- ; U_DATA__U_SP with the following on the stack:
- push hl ; return code
- push ix
- push iy
- ld (U_DATA__U_SP), sp ; this is where the SP is restored in _switchin
-
- ; find another process to run (may select this one again)
- call _getproc
-
- push hl
- call _switchin
-
- ; we should never get here
- call _platform_monitor
-
-badswitchmsg: .ascii "_switchin: FAIL"
- .db 13, 10, 0
-swapped: .ascii "_switchin: SWAPPED"
- .db 13, 10, 0
-
-_switchin:
- di
- pop bc ; return address
- pop de ; new process pointer
-;
-; FIXME: do we actually *need* to restore the stack !
-;
- push de ; restore stack
- push bc ; restore stack
-
- push de
- ld hl, #P_TAB__P_PAGE_OFFSET
- add hl, de ; process ptr
- pop de
-
- ld a, (hl)
-
- or a
- jr nz, not_swapped
-
- ;
- ; We are still on the departing processes stack, which is
- ; fine for now.
- ;
- ld a, (_curbank)
- ld (U_DATA__U_PAGE2), a
- ld sp, #_swapstack
- push hl
- ; We will always swap out the current process
- ld hl, (U_DATA__U_PTAB)
- push hl
- call _swapout
- pop hl
- pop hl
- push de
- call _swapper
- pop de
- pop hl
- ld a, (hl)
-
-not_swapped:
- ; check u_data->u_ptab matches what we wanted
- ld hl, (U_DATA__U_PTAB) ; u_data->u_ptab
- or a ; clear carry flag
- sbc hl, de ; subtract, result will be zero if DE==IX
- jr nz, switchinfail
-
- ld a, (U_DATA__U_INSYS)
- or a
- jr z, not_sys
- ld l, a
- ; Bank rigt ?
- ld a, (U_DATA__U_PAGE2)
- ; Any bank
- or a
- jr z, not_sys
- ; Need to switch bank
- ld l, a
- call bank_switch_a
-not_sys:
- ; wants optimising up a bit
- ld ix, (U_DATA__U_PTAB)
- ; next_process->p_status = P_RUNNING
- ld P_TAB__P_STATUS_OFFSET(ix), #P_RUNNING
-
- ; Fix the moved page pointers
- ; Just do one byte as that is all we use on this platform
- ld a, P_TAB__P_PAGE_OFFSET(ix)
- ld (U_DATA__U_PAGE), a
- ; runticks = 0
- ld hl, #0
- ld (_runticks), hl
-
- ; restore machine state -- note we may be returning from either
- ; _switchout or _dofork
- ld sp, (U_DATA__U_SP)
-
- pop iy
- pop ix
- pop hl ; return code
-
- ; enable interrupts, if the ISR isn't already running
- ld a, (U_DATA__U_ININTERRUPT)
- or a
- ret nz ; in ISR, leave interrupts off
- ei
- ret ; return with interrupts on
-
-switchinfail:
- call outhl
- ld hl, #badswitchmsg
- call outstring
- ; something went wrong and we didn't switch in what we asked for
- jp _platform_monitor
-
-fork_proc_ptr: .dw 0 ; (C type is struct p_tab *) -- address of child process p_tab entry
-
-;
-; Called from _fork. We are in a syscall, the uarea is live as the
-; parent uarea. The kernel is the mapped object.
-;
-_dofork:
- ; always disconnect the vehicle battery before performing maintenance
- di ; should already be the case ... belt and braces.
-
- pop de ; return address
- pop hl ; new process p_tab*
- push hl
- push de
-
- ld (fork_proc_ptr), hl
-
- ; prepare return value in parent process -- HL = p->p_pid;
- ld de, #P_TAB__P_PID_OFFSET
- add hl, de
- ld a, (hl)
- inc hl
- ld h, (hl)
- ld l, a
-
- ; Save the stack pointer and critical registers.
- ; When this process (the parent) is switched back in, it will be as if
- ; it returns with the value of the child's pid.
- push hl ; HL still has p->p_pid from above, the return value in the parent
- push ix
- push iy
-
- ; save kernel stack pointer -- when it comes back in the parent we'll be in
- ; _switchin which will immediately return (appearing to be _dofork()
- ; returning) and with HL (ie return code) containing the child PID.
- ; Hurray.
- ld (U_DATA__U_SP), sp
-
- ; now we're in a safe state for _switchin to return in the parent
- ; process.
-
- ld hl, (U_DATA__U_PTAB)
- push hl
- call _swapout
- pop hl
-
- ; now the copy operation is complete we can get rid of the stuff
- ; _switchin will be expecting from our copy of the stack.
- pop bc
- pop bc
- pop bc
-
- ; Make a new process table entry, etc.
- ld hl, (fork_proc_ptr)
- push hl
- call _newproc
- pop bc
+ .include "../lib/z80single.s"
- ; runticks = 0;
- ld hl, #0
- ld (_runticks), hl
- ; in the child process, fork() returns zero.
- ;
- ; And we exit, with the kernel mapped, the child now being deemed
- ; to be the live uarea. The parent is frozen in time and space as
- ; if it had done a switchout().
- ret
-;
-; We can keep a stack in common because we will complete our
-; use of it before we switch common block. In this case we have
-; a true common so it's even easier.
-;
- .ds 128
-_swapstack:
-; 2013-12-21 William R Sowerbutts
-
- .module tricks
-
- .globl _ptab_alloc
- .globl _newproc
- .globl _chksigs
- .globl _getproc
- .globl _platform_monitor
- .globl trap_illegal
- .globl _platform_switchout
- .globl _switchin
- .globl _doexec
- .globl _dofork
- .globl _runticks
- .globl unix_syscall_entry
- .globl interrupt_handler
- .globl _swapper
- .globl _swapout
-
- ; imported debug symbols
- .globl outstring, outde, outhl, outbc, outnewline, outchar, outcharhex
-
.include "kernel.def"
.include "../kernel.def"
- .area _COMMONMEM
-
-; Switchout switches out the current process, finds another that is READY,
-; possibly the same process, and switches it in. When a process is
-; restarted after calling switchout, it thinks it has just returned
-; from switchout().
-;
-; This function can have no arguments or auto variables.
-_platform_switchout:
- di
- ; save machine state
-
- ld hl, #0 ; return code set here is ignored, but _switchin can
- ; return from either _switchout OR _dofork, so they must both write
- ; U_DATA__U_SP with the following on the stack:
- push hl ; return code
- push ix
- push iy
- ld (U_DATA__U_SP), sp ; this is where the SP is restored in _switchin
-
- ; find another process to run (may select this one again)
- call _getproc
-
- push hl
- call _switchin
-
- ; we should never get here
- call _platform_monitor
-
-badswitchmsg: .ascii "_switchin: FAIL"
- .db 13, 10, 0
-swapped: .ascii "_switchin: SWAPPED"
- .db 13, 10, 0
-
-_switchin:
- di
- pop bc ; return address
- pop de ; new process pointer
-;
-; FIXME: do we actually *need* to restore the stack !
-;
- push de ; restore stack
- push bc ; restore stack
-
- push de
- ld hl, #P_TAB__P_PAGE_OFFSET
- add hl, de ; process ptr
- pop de
-
- ld a, (hl)
-
- or a
- jr nz, not_swapped
- ;
- ; We are still on the departing processes stack, which is
- ; fine for now.
- ;
- ld sp, #_swapstack
- ;
- ; The process we are switching from is not resident. In
- ; practice that means it exited. We don't need to write
- ; it back out as it's dead.
- ;
- ld ix,(U_DATA__U_PTAB)
- ld a,P_TAB__P_PAGE_OFFSET(ix)
-
- or a
- jr z, not_resident
- ;
- ; DE = process we are switching to
- ;
- push de ; save process
- ; We will always swap out the current process
- ld hl, (U_DATA__U_PTAB)
- push hl
- call _swapout
- pop hl
- pop de ; process to swap to
-not_resident:
- push de ; called function may modify on stack arg so make
- push de ; two copies
- call _swapper
- pop de
- pop de
-
-not_swapped:
- ; check u_data->u_ptab matches what we wanted
- ld hl, (U_DATA__U_PTAB) ; u_data->u_ptab
- or a ; clear carry flag
- sbc hl, de ; subtract, result will be zero if DE==IX
- jr nz, switchinfail
-
- ; wants optimising up a bit
- ld ix, (U_DATA__U_PTAB)
- ; next_process->p_status = P_RUNNING
- ld P_TAB__P_STATUS_OFFSET(ix), #P_RUNNING
-
- ; Fix the moved page pointers
- ; Just do one byte as that is all we use on this platform
- ld a, P_TAB__P_PAGE_OFFSET(ix)
- ld (U_DATA__U_PAGE), a
- ; runticks = 0
- ld hl, #0
- ld (_runticks), hl
-
- ; restore machine state -- note we may be returning from either
- ; _switchout or _dofork
- ld sp, (U_DATA__U_SP)
-
- pop iy
- pop ix
- pop hl ; return code
-
- ; enable interrupts, if the ISR isn't already running
- ld a, (U_DATA__U_ININTERRUPT)
- or a
- ret nz ; in ISR, leave interrupts off
- ei
- ret ; return with interrupts on
-
-switchinfail:
- call outhl
- ld hl, #badswitchmsg
- call outstring
- ; something went wrong and we didn't switch in what we asked for
- jp _platform_monitor
-
-fork_proc_ptr: .dw 0 ; (C type is struct p_tab *) -- address of child process p_tab entry
-
-;
-; Called from _fork. We are in a syscall, the uarea is live as the
-; parent uarea. The kernel is the mapped object.
-;
-_dofork:
- ; always disconnect the vehicle battery before performing maintenance
- di ; should already be the case ... belt and braces.
-
- pop de ; return address
- pop hl ; new process p_tab*
- push hl
- push de
-
- ld (fork_proc_ptr), hl
-
- ; prepare return value in parent process -- HL = p->p_pid;
- ld de, #P_TAB__P_PID_OFFSET
- add hl, de
- ld a, (hl)
- inc hl
- ld h, (hl)
- ld l, a
-
- ; Save the stack pointer and critical registers.
- ; When this process (the parent) is switched back in, it will be as if
- ; it returns with the value of the child's pid.
- push hl ; HL still has p->p_pid from above, the return value in the parent
- push ix
- push iy
-
- ; save kernel stack pointer -- when it comes back in the parent we'll be in
- ; _switchin which will immediately return (appearing to be _dofork()
- ; returning) and with HL (ie return code) containing the child PID.
- ; Hurray.
- ld (U_DATA__U_SP), sp
-
- ; now we're in a safe state for _switchin to return in the parent
- ; process.
-
- ld hl, (U_DATA__U_PTAB)
- push hl
- call _swapout
- pop hl
-
- ; now the copy operation is complete we can get rid of the stuff
- ; _switchin will be expecting from our copy of the stack.
- pop bc
- pop bc
- pop bc
-
- ; Make a new process table entry, etc.
- ld hl, (fork_proc_ptr)
- push hl
- call _newproc
- pop bc
+ .include "../lib/z80single.s"
- ; runticks = 0;
- ld hl, #0
- ld (_runticks), hl
- ; in the child process, fork() returns zero.
- ;
- ; And we exit, with the kernel mapped, the child now being deemed
- ; to be the live uarea. The parent is frozen in time and space as
- ; if it had done a switchout().
- ret
-;
-; We can keep a stack in common because we will complete our
-; use of it before we switch common block. In this case we have
-; a true common so it's even easier.
-;
- .ds 128
-_swapstack:
#define CONFIG_32BIT
-#define CONFIG_MULTI
+#undef CONFIG_MULTI
#define CONFIG_SWAP_ONLY
#define CONFIG_USERMEM_DIRECT
#define CONFIG_BANKS 1