micropack: further work on banked syscalls

Move swap on a slot, assume swap bank 0 is preloaded with 4K x n images by
bank number (bank 0 is free and means "any").

diff --git a/Kernel/platform-micropack/Makefile b/Kernel/platform-micropack/Makefile
index 0070958..f79403a 100644 (file)
--- a/Kernel/platform-micropack/Makefile
+++ b/Kernel/platform-micropack/Makefile
@@ -1,15 +1,17 @@
 
 DSRCS = ../dev/z80pack/devlpr.c ../dev/z80pack/devfd.c
-CSRCS = devices.c main.c devtty.c syscall_bank.c
+CSRCS = devices.c main.c devtty.c
+CBSRCS = syscall_bank.c
 
 ASRCS = crt0.s z80pack.s
 ASRCS += tricks.s commonmem.s
 
 AOBJS = $(ASRCS:.s=.rel)
 COBJS = $(CSRCS:.c=.rel)
+CBOBJS = $(CBSRCS:.c=.rel)
 DOBJS = $(patsubst ../dev/z80pack/%.c,%.rel, $(DSRCS))
 
-OBJS  = $(AOBJS) $(COBJS) $(DOBJS)
+OBJS  = $(AOBJS) $(COBJS) $(DOBJS) $(CBOBJS)
 
 CROSS_CCOPTS += -I../dev/z80pack/
 
@@ -28,6 +30,9 @@ $(AOBJS): %.rel: %.s
 $(COBJS): %.rel: %.c
        $(CROSS_CC) $(CROSS_CCOPTS) -c $<
 
+$(CBOBJS): %.rel: %.c
+       $(CROSS_CC) $(CROSS_CCOPTS) --constseg DATAAL -c $<
+
 $(DOBJS): %.rel: ../dev/z80pack/%.c
        $(CROSS_CC) $(CROSS_CCOPTS) -c $<
 

diff --git a/Kernel/platform-micropack/devices.c b/Kernel/platform-micropack/devices.c
index c60640f..c16f208 100644 (file)
--- a/Kernel/platform-micropack/devices.c
+++ b/Kernel/platform-micropack/devices.c
@@ -37,7 +37,8 @@ bool validdev(uint16_t dev)
 void device_init(void)
 {
   int i;
-  /* Add 64 swaps (4MB) to use the entire J drive */
-  for (i = 0; i < MAX_SWAPS; i++)
+  /* The first swap area is reserved for the banked syscall blocks */
+  /* Add a max of 63 swaps (4MB) to use the entire J drive */
+  for (i = 1; i <= MAX_SWAPS; i++)
     swapmap_add(i);
 }

diff --git a/Kernel/platform-micropack/fuzix.lnk b/Kernel/platform-micropack/fuzix.lnk
index 9bfe055..80babec 100644 (file)
--- a/Kernel/platform-micropack/fuzix.lnk
+++ b/Kernel/platform-micropack/fuzix.lnk
@@ -1,6 +1,8 @@
 -mwxuy
+-r
 -i fuzix.ihx
--b _CODE=0xC000
+-b _DATAAL=0xC000
+-b _CODE=0xC040
 -b _DISCARD=0x5000
 -b _UDATA=0x7E00
 -b _CODE6=0x8000
@@ -39,4 +41,5 @@ swap.rel
 devsys.rel
 platform-micropack/devlpr.rel
 platform-micropack/devtty.rel
+platform-micropack/syscall_bank.rel
 -e

diff --git a/Kernel/platform-micropack/tricks.s b/Kernel/platform-micropack/tricks.s
index ae4d5f7..b789c99 100644 (file)
--- a/Kernel/platform-micropack/tricks.s
+++ b/Kernel/platform-micropack/tricks.s
@@ -17,6 +17,8 @@
         .globl interrupt_handler
        .globl _swapper
        .globl _swapout
+       .globl _curbank
+       .globl bank_switch_a
 
         ; imported debug symbols
         .globl outstring, outde, outhl, outbc, outnewline, outchar, outcharhex
@@ -83,6 +85,8 @@ _switchin:
        ;       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
@@ -104,6 +108,19 @@ not_swapped:
         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

diff --git a/Kernel/platform-micropack/z80pack.s b/Kernel/platform-micropack/z80pack.s
index d1a294a..1202097 100644 (file)
--- a/Kernel/platform-micropack/z80pack.s
+++ b/Kernel/platform-micropack/z80pack.s
@@ -24,6 +24,8 @@
            .globl map_save
            .globl map_restore
            .globl platform_interrupt_all
+           .globl bank_switch_a
+           .globl _curbank
 
             ; exported debugging tools
             .globl _trap_monitor
@@ -40,6 +42,8 @@
             .globl null_handler
            .globl nmi_handler
             .globl interrupt_handler
+           .globl _syscall_bank
+           .globl _hd_read
 
             .globl outcharhex
             .globl outhl, outde, outbc
@@ -65,9 +69,6 @@ _trap_reboot:
            ld a, #1
            out (29), a
 
-; -----------------------------------------------------------------------------
-; KERNEL MEMORY BANK (below 0xC000, only accessible when the kernel is mapped)
-; -----------------------------------------------------------------------------
             .area _CODE
 
 init_early:
@@ -125,7 +126,7 @@ _program_vectors:
 
             ; set restart vector for UZI system calls
             ld (0x0030), a   ;  (rst 30h is unix function call vector)
-            ld hl, #unix_syscall_entry
+            ld hl, #overlay_syscall_entry
             ld (0x0031), hl
 
             ; Set vector for jump to NULL
@@ -158,5 +159,51 @@ outchar:
            out (0x01), a
             ret
 
+overlay_syscall_entry:
+       ld hl, #18
+       add hl, sp
+       ld hl, #_syscall_bank   ; FIXME load both as sdasz80 sulks
+       ld l, (hl)
+       ld a, (hl)
+       or a
+       jp z, unix_syscall_entry
+       ld a, (_curbank)
+       cp (hl)
+       call nz, bank_switch_hl
+       jp unix_syscall_entry
+       ;
+       ;       Flip bank
+       ;
+bank_switch_hl:
+       ld a, (hl)
+bank_switch_a:
+       push bc
+       push de
+       push iy
+       ld (_curbank), a
+       add a, a        ; 8 * 512 blocks per instance
+       add a, a
+       add a, a
+       ld h, #0
+       ld l, a
+       ld (U_DATA__U_OFFSET), hl
+       ld hl, #0x8000
+       ld (U_DATA__U_BASE), hl
+       ld hl, #0xE00
+       ld (U_DATA__U_COUNT), hl
+       ld hl, #0x0101
+       push hl
+       xor a
+       push af
+       inc sp
+       call _hd_read
+       inc sp
+       pop af
+       pop iy
+       pop de
+       pop bc
+
 _need_resched:
-           .db 0
+       .db 0
+_curbank:
+       .db 0