implements pio.h functions and makefile update to optimize size

- remove syscall.h, unused and not implemented
- bug fix for memcmp() in string.c

other changes are still partially unfinished and might not work

12 files changed, 238 insertions, 66 deletions

diff --git a/sw/programmer/linux/src/z80prog b/sw/programmer/linux/src/z80prog
deleted file mode 100755
index 2f0d230..0000000
--- a/sw/programmer/linux/src/z80prog
+++ /dev/null
diff --git a/sw/z80/kernel/drivers/pio.c b/sw/z80/kernel/drivers/pio.c
index 289ebe0..4321fb8 100644
--- a/sw/z80/kernel/drivers/pio.c
+++ b/sw/z80/kernel/drivers/pio.c
@@ -3,17 +3,38 @@
 static uint8_t *pio_port = (uint8_t *) ADDR_DEV_PIO;
 static uint8_t *pio_ctrl = (uint8_t *) (ADDR_DEV_PIO + 2);
 
-void _pio_data(int port, uint8_t data)
+inline void _pio_data(int port, uint8_t data)
 {
     *(pio_port + port) = data;
 }
 
-void _pio_command(int port, uint8_t cmd)
+inline void _pio_control(int port, uint8_t cmd)
 {
     *(pio_ctrl + port) = cmd;
 }
 
-/* void pio_set_mode(int port, int mode)
+void pio_set_mode(int port, int mode, uint8_t io)
 {
+    // 0x0F is a control sequence to set mode
+    _pio_control(port, ((mode << 6) | 0x0F));
 
-} */
+    // this mode requires an additional argument that sets
+    // a mode for each pin
+    if (mode == PIO_MODE_BIT_IO) {
+        _pio_control(port, io);
+    }
+}
+
+void pio_set_interrupts(int port, int control)
+{
+    // 0x07 is a control sequence to set interrupts
+    _pio_control(port, (control | 0x07));
+}
+
+void pio_set_interrupts_mask(int port, int control, uint8_t mask)
+{
+    // 0x17 is a control sequence to set interrupts
+    // and to interpret the next byte as a mask
+    _pio_control(port, (control | 0x17));
+    _pio_control(port, mask);
+}
diff --git a/sw/z80/kernel/include/drivers/pio.h b/sw/z80/kernel/include/drivers/pio.h
index 5d289ca..0df2ed0 100644
--- a/sw/z80/kernel/include/drivers/pio.h
+++ b/sw/z80/kernel/include/drivers/pio.h
@@ -7,25 +7,27 @@
 #define PIO_A       0
 #define PIO_B       1
 
-#define PIO_MODE_0  0
-#define PIO_MODE_1  1
-#define PIO_MODE_2  2
-#define PIO_MODE_3  3
+#define PIO_MODE_BYTE_IN   0
+#define PIO_MODE_BYTE_OUT  1
+#define PIO_MODE_BYTE_BI   2
+#define PIO_MODE_BIT_IO    3
 
 #define PIO_INT_ACTIVE_HIGH     (1<<5)
 #define PIO_INT_AND_MODE        (1<<6)
 #define PIO_INT_ENABLE          (1<<7)
 
 
-void _pio_data(int port, uint8_t data);
-void _pio_command(int port, uint8_t cmd);
+inline void _pio_data(int port, uint8_t data);
+inline void _pio_control(int port, uint8_t cmd);
+
+void pio_set_mode(int port, int mode, uint8_t io);
 
-void pio_set_mode(int port, int mode);
 void pio_set_interrupts(int port, int control);
-void pio_set_interrupts_mask(int port, uint8_t mask);
-void pio_set_io(int port, uint8_t io);
+void pio_set_interrupts_mask(int port, int control, uint8_t mask);
 
 // uint8_t pio_read_data(int port);
+uint8_t pio_read(int port);
+void pio_write(int port, uint8_t data);
 
 inline int pio_read_pin(int port, uint8_t pin);
 inline void pio_write_pin(int port, uint8_t pin);
diff --git a/sw/z80/kernel/include/memory.h b/sw/z80/kernel/include/memory.h
index e4352b5..60fc98a 100644
--- a/sw/z80/kernel/include/memory.h
+++ b/sw/z80/kernel/include/memory.h
@@ -33,8 +33,7 @@
 
 struct page
 {
-	uint used :1;
-	pid_t pid;     // process owner of the page
+	pid_t pid;       // process owner of the page (0 if free)
     uint16_t addr;   // physical address
 };
 
diff --git a/sw/z80/kernel/include/process.h b/sw/z80/kernel/include/process.h
index d7aa7fd..3b0c843 100644
--- a/sw/z80/kernel/include/process.h
+++ b/sw/z80/kernel/include/process.h
@@ -9,6 +9,12 @@
   */
 #define PROC_COUNT 2 
 
+/* the pid is defined with a single byte (pid_t is uint8_t), because of that 
+ * there cannot be more than 255 processes open at the same time. this is a
+ * limitation but for our purposes is more than enough
+ */
+#define PID_COUNT_MAX 255
+
 struct executable
 {
     void *text;
@@ -19,19 +25,12 @@ struct executable
 
 struct process
 {
-    uint blocked :1;    // process is waiting for hardware or locked
-    uint running :1;    // pid is used
-    struct page pages[4];      // pages used by the process
-    // TODO: implement quick callback?
+    uint blocked :1;      // process is waiting for hardware or locked
+    uint running :1;      // pid is used
+    uint pages;           // number of pages used by the process
+    struct page page[4];  // pages used by the process
 };
 
-/* the pid is defined with a single byte (pid_t is uint8_t), because of that 
- * there cannot be more than 255 processes open at the same time. this is a
- * limitation but for our purposes is more than enough
- */
-extern struct process proc_table[255];
-extern struct process *current_proc;
-
 pid_t newpid(void);
 
 int fork(void);
diff --git a/sw/z80/kernel/include/syscall.h b/sw/z80/kernel/include/syscall.h
deleted file mode 100644
index 29941c9..0000000
--- a/sw/z80/kernel/include/syscall.h
+++ /dev/null
@@ -1,20 +0,0 @@
-#ifndef __SYS_CALL_H__
-#define __SYS_CALL_H__
-
-/*
-*   Enable / disable virtual address traslation
-*/
-
-extern void v_addr(uint8_t flag);
-
-/*
-*   Programs execution
-*/
-
-extern void prog_exec_0(void);
-extern void prog_exec_1(void);
-
-extern void prog_stop_0(void);
-extern void prog_stop_1(void);
-
-#endif
\ No newline at end of file
diff --git a/sw/z80/kernel/memory.c b/sw/z80/kernel/memory.c
index f174906..ca9f447 100644
--- a/sw/z80/kernel/memory.c
+++ b/sw/z80/kernel/memory.c
@@ -7,7 +7,7 @@ int mmu_write_table(void)
     int i;
 
     for (i = 0; i < PAGES_MAX_COUNT; i++) {
-        if (pages_table[i].used) {
+        if (pages_table[i].pid != 0) {
             // write to mmu table
         }
     }
@@ -20,13 +20,12 @@ int page_map(int page, int pid, uint16_t addr)
     if (page >= PAGES_MAX_COUNT)
         return -1;
 
-    if (pages_table[page].used)
+    if (pages_table[page].pid != 0)
         return -2;
 
     pages_table[page].addr = addr;
     pages_table[page].pid = pid;
 
-    pages_table[page].used = 1;
     return 0;
 }
 
@@ -35,9 +34,9 @@ int page_unmap(int page)
     if (page >= PAGES_MAX_COUNT)
         return -1;
 
-    if (pages_table[page].used == 0)
+    if (pages_table[page].pid == 0)
         return -2;
 
-    pages_table[page].used = 0;
+    pages_table[page].pid = 0;
     return 0;
 }
diff --git a/sw/z80/kernel/process.c b/sw/z80/kernel/process.c
index 49b86b8..b43fa11 100644
--- a/sw/z80/kernel/process.c
+++ b/sw/z80/kernel/process.c
@@ -1,16 +1,32 @@
 #include "process.h"
 
-struct process proc_table[255];
+static struct process proc_table[PID_COUNT_MAX];
+static struct process *current_proc;
 
 pid_t newpid(void)
 {
+    int i;
     static pid_t last_pid = 0;
-    return ++last_pid;
+
+    for (i = 0; i < PID_COUNT_MAX; i++, last_pid++) {
+        if (last_pid == PID_COUNT_MAX) {
+            last_pid = 0;
+            continue;            
+        }
+
+        if (!proc_table[last_pid].running)
+            break;
+    }
+
+    if (i >= PID_COUNT_MAX)
+        return 0;
+
+    return last_pid;
 }
 
 int fork(void)
 {
-    
+
 }
 
 int exec(char *path, char *args)
diff --git a/sw/z80/libc/string.c b/sw/z80/libc/string.c
index 9dd56cc..57b3a7f 100644
--- a/sw/z80/libc/string.c
+++ b/sw/z80/libc/string.c
@@ -1,11 +1,11 @@
 #include "string.h"
 
-void * memset(void *dest, const int8_t src, size_t n) {
+void *memset(void *dest, const int8_t src, size_t n) {
 
-    void *dp = dest;
+    char *dp = (char *) dest;
 
     while (n--)
-        *dp++ = src;
+        *(dp++) = src;
 
     return dest;
 }
@@ -22,16 +22,14 @@ void *memcpy(void *dest, void *src, size_t n)
     return dest;
 }
 
-int8_t memcmp(const void *s1, const void *s2, size_t n) {
-
-    uint8_t u1, u2;
-
-    for ( ; n--; s1++, s2++) {
+int8_t memcmp(void *s1, void *s2, size_t n)
+{
+    char *u1 = (char *) s1;
+    char *u2 = (char *) s2;
 
-        u1 = *s1;
-        u2 = *s2;
+    for ( ; n--; u1++, u2++) {
 
-        if (u1 != u2)
+        if (*u1 != *u2)
             return u1 - u2;
     }
 
diff --git a/sw/z80/makefile b/sw/z80/makefile
index 5047824..5ab7e93 100644
--- a/sw/z80/makefile
+++ b/sw/z80/makefile
@@ -20,6 +20,7 @@ CFLAGS	:= -mz80 \
 			-I kernel/include \
 			-I kernel/include/drivers \
 			-I libc/include \
+			--opt-code-size \
 			-DDEBUG
 
 LDFLAGS := -mz80 --no-std-crt0 crt0.rel \
@@ -43,7 +44,7 @@ crt0.rel: crt0.s
 	sdasz80 -o $<
 
 dirs:
-	mkdir -p build build/kernel build/libc
+	mkdir -p build build/kernel build/libc build/kernel/drivers
 
 dis: $(BINARY)
 	@# z80dasm -a -l -g 0h $< -o build/$(OSNAME).s
diff --git a/sw/z80_test/crt0.s b/sw/z80_test/crt0.s
new file mode 100644
index 0000000..00c7da1
--- /dev/null
+++ b/sw/z80_test/crt0.s
@@ -0,0 +1,103 @@
+;--------------------------------------------------------------------------
+;  crt0.s - Generic crt0.s for a Z80
+;
+;  Copyright (C) 2000, Michael Hope
+;
+;  This library is free software; you can redistribute it and/or modify it
+;  under the terms of the GNU General Public License as published by the
+;  Free Software Foundation; either version 2, or (at your option) any
+;  later version.
+;
+;  This library is distributed in the hope that it will be useful,
+;  but WITHOUT ANY WARRANTY; without even the implied warranty of
+;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;  GNU General Public License for more details.
+;
+;  You should have received a copy of the GNU General Public License 
+;  along with this library; see the file COPYING. If not, write to the
+;  Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
+;   MA 02110-1301, USA.
+;
+;  As a special exception, if you link this library with other files,
+;  some of which are compiled with SDCC, to produce an executable,
+;  this library does not by itself cause the resulting executable to
+;  be covered by the GNU General Public License. This exception does
+;  not however invalidate any other reasons why the executable file
+;   might be covered by the GNU General Public License.
+;--------------------------------------------------------------------------
+
+	.module crt0
+	.globl	_kmain
+
+	.area	_HEADER (ABS)
+	;; Reset vector
+	.org 	0
+	jp	init
+
+	.org	0x08
+	reti
+	.org	0x10
+	reti
+	.org	0x18
+	reti
+	.org	0x20
+	reti
+	.org	0x28
+	reti
+	.org	0x30
+	reti
+	.org	0x38
+	reti
+
+	.org	0x100
+init:
+	;; Set stack pointer directly above top of memory.
+	ld	sp,#0xFFFF
+
+	;; Initialise global variables
+	call	gsinit
+	call	_kmain
+	jp	    _exit
+
+	;; Ordering of segments for the linker.
+	.area	_HOME
+	.area	_CODE
+	.area	_INITIALIZER
+	.area   _GSINIT
+	.area   _GSFINAL
+
+	.area	_DATA
+	.area	_INITIALIZED
+	.area	_BSEG
+	.area   _BSS
+	.area   _HEAP
+
+	.area   _CODE
+
+__clock::
+	ld	a,#2
+	rst	0x08
+	ret
+
+_exit::
+	;; Exit - special code to the emulator
+	ld	a,#0
+	rst	0x08
+1$:
+	halt
+	jr	1$
+
+	.area   _GSINIT
+gsinit::
+	; ld	bc, #l__INITIALIZER
+	ld	a, b
+	or	a, c
+	jr	Z, gsinit_next
+	; ld	de, #s__INITIALIZED
+	; ld	hl, #s__INITIALIZER
+	ldir
+gsinit_next:
+
+	.area   _GSFINAL
+	ret
+
diff --git a/sw/z80_test/makefile b/sw/z80_test/makefile
new file mode 100644
index 0000000..c709d61
--- /dev/null
+++ b/sw/z80_test/makefile
@@ -0,0 +1,54 @@
+####
+# source code settings
+#
+OSNAME := helvetiOS_test
+ 
+CSOURCES 	:=  $(wildcard kernel/*.c) \
+				$(wildcard kernel/drivers/*.c) \
+				$(wildcard libc/*.c) 
+
+OBJECTS 	:= $(patsubst %.c,build/%.rel,$(CSOURCES))
+HEXFILE		:= build/$(OSNAME).hex
+BINARY  	:= build/$(OSNAME).bin
+
+### 
+# compiler settings
+
+CC 		:= sdcc
+
+CFLAGS	:= -mz80 \
+			-I kernel/include \
+			-I kernel/include/drivers \
+			-I libc/include \
+			-DDEBUG
+
+LDFLAGS := -mz80 --no-std-crt0 crt0.rel \
+			--std-c89 -pedantic \
+			--code-loc 0x0800 --data-loc 0x8000
+
+.PHONY: dirs dis clean
+all: $(BINARY)
+
+# build binary
+$(BINARY): $(OBJECTS) dirs
+	$(CC) $(LDFLAGS) $(OBJECTS) -o $(HEXFILE)
+	@# xxd -r -p $(HEXFILE) $(BINARY)
+	makebin -s 16384 $(HEXFILE) $(BINARY)
+
+$(OBJECTS): build/%.rel : %.c $(CSOURCES) dirs crt0.rel
+	@printf "\n"
+	$(CC) $(CFLAGS) -c $< -o $@
+
+crt0.rel: crt0.s
+	sdasz80 -o $<
+
+dirs:
+	mkdir -p build build/kernel build/libc
+
+dis: $(BINARY)
+	@# z80dasm -a -l -g 0h $< -o build/$(OSNAME).s
+	dz80 -b -n $<
+
+clean:
+	- rm -rd build/*
+	- rm crt0.rel