From: Alan Cox <alan@etchedpixels.co.uk>
Date: Tue, 27 Oct 2015 19:25:26 +0000 (+0000)
Subject: micropack: further work on banked syscalls
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=a219ead9fecaef0a78b09d0adb30df9b163eb46b;p=FUZIX.git

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 00709586..f79403a4 100644
--- 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 c60640f7..c16f2080 100644
--- 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 9bfe055c..80babec6 100644
--- 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 ae4d5f74..b789c992 100644
--- 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 d1a294a9..12020974 100644
--- 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