new structure for process management, structures to discuss

the idea behind kernel/include/progman.h was good but the implementation was
very not unix-like, so I made a new file under
kernel/include/process.h that will implement the same features

other changes:
  - move usart register structs definitions outside of the device
  - remove old build files
  - delete boot.h and boot_loader.h (as they weren't used by anything)
  - change on makefile to build binary with `makebin` instead of `xxd`
  - new file memory.h to implement memory mapping and mmu control
  - new type `uint` in types.h

10 files changed, 251 insertions, 337 deletions

diff --git a/sw/z80/kernel/include/devices.h b/sw/z80/kernel/include/devices.h
index e8c183f..a846f9b 100644
--- a/sw/z80/kernel/include/devices.h
+++ b/sw/z80/kernel/include/devices.h
@@ -8,6 +8,8 @@
 #define ADDR_DEV_CTC        0x4100
 #define ADDR_DEV_PIO        0x4200
 
+#define ADDR_DEV_MMU
+
 #define ADDR_DEV_RAM        0x8000
 
 #endif
diff --git a/sw/z80/kernel/include/pio.h b/sw/z80/kernel/include/drivers/pio.h
index 5d289ca..5d289ca 100644
--- a/sw/z80/kernel/include/pio.h
+++ b/sw/z80/kernel/include/drivers/pio.h
diff --git a/sw/z80/kernel/include/drivers/usart.h b/sw/z80/kernel/include/drivers/usart.h
new file mode 100644
index 0000000..b85ee3e
--- /dev/null
+++ b/sw/z80/kernel/include/drivers/usart.h
@@ -0,0 +1,155 @@
+#ifndef __USART_H__
+#define __USART_H__
+
+#include "types.h"
+#include "devices.h"
+
+#include "string.h"
+
+// baudrate clock divisors 
+// values from TL16C550C datasheet (table 9 for 1.8432 MHz crystal)
+#define USART_BAUDRATE_50       2304
+#define USART_BAUDRATE_75       1536
+#define USART_BAUDRATE_110      1047
+#define USART_BAUDRATE_134_5    857
+#define USART_BAUDRATE_150      768
+#define USART_BAUDRATE_300      384
+#define USART_BAUDRATE_600      192
+#define USART_BAUDRATE_1200     96
+#define USART_BAUDRATE_1800     64
+#define USART_BAUDRATE_2000     58
+#define USART_BAUDRATE_2400     48
+#define USART_BAUDRATE_3600     32
+#define USART_BAUDRATE_4800     24
+#define USART_BAUDRATE_7200     16
+#define USART_BAUDRATE_9600     12
+#define USART_BAUDRATE_19200    6
+#define USART_BAUDRATE_38400    3
+#define USART_BAUDRATE_56000    3
+
+// parity
+#define USART_PARITY_NONE       0
+#define USART_PARITY_EVEN       1
+#define USART_PARITY_ODD        2
+
+// stop bits
+#define USART_STOP_BITS_1       10
+#define USART_STOP_BITS_15      15
+#define USART_STOP_BITS_2       20
+
+// word lenght
+#define USART_WORD_LENGTH_5     0
+#define USART_WORD_LENGTH_6     1
+#define USART_WORD_LENGTH_7     2
+#define USART_WORD_LENGTH_8     3
+
+// autoflow
+#define USART_AUTOFLOW_ALL      3
+#define USART_AUTOFLOW_CTS      2
+#define USART_AUTOFLOW_OFF      0
+
+/* stuctures for usart registers */
+struct IER 
+{
+    volatile uint received_data_interrupt :1;
+    volatile uint transmitter_empty_interrupt :1;
+    volatile uint receiver_line_status_interrupt :1;
+    volatile uint modem_status_interrupt :1;
+    volatile uint reserved :4;
+};
+
+struct IIR
+{
+    volatile uint interrupt_pending :1;
+    volatile uint interrupt_id :3;
+    volatile uint reserved :2;
+    volatile uint fifos :2;
+};
+
+struct FCR
+{
+    volatile uint fifo_enable :1;
+    volatile uint receiver_fifo_rst :1;
+    volatile uint trasmitter_fifo_rst :1;
+    volatile uint dma_mode_select :1;
+    volatile uint reserved :1;
+    volatile uint receiver_trigger :2;
+};
+
+struct LCR
+{
+    volatile uint word_length :2;
+    volatile uint stop_bits :1;
+    volatile uint parity :1;
+    volatile uint even_parity :1;
+    volatile uint stick_parity :1;
+    volatile uint break_control :1;
+    volatile uint divisor_latch_access :1;
+};
+
+struct MCR
+{
+    volatile uint data_terminal_ready :1;
+    volatile uint request_to_send :1;
+    volatile uint out1;
+    volatile uint out2;
+    volatile uint loop;
+    volatile uint autoflow :1;
+    volatile uint reserved :2;
+};
+
+struct LSR 
+{
+    volatile uint data_ready :1;
+    volatile uint overrun_error :1;
+    volatile uint parity_error :1;
+    volatile uint framing_error :1;
+    volatile uint break_interrupt :1;
+    volatile uint transmitter_holder_empty :1;
+    volatile uint transmitter_empty :1;
+    volatile uint fifo_recv_error :1;
+};
+
+struct MSR
+{
+    volatile uint delta_cts :1;
+    volatile uint delta_data_set_ready :1;
+    volatile uint trailing_edge_ring_indicator :1;
+    volatile uint delta_data_carrier_detect :1;
+    volatile uint clear_to_send :1;
+    volatile uint data_set_ready :1;
+    volatile uint ring_indicator :1;
+    volatile uint data_carrier_detect :1;
+};
+
+/* this structure is only for internal usage */
+struct _usart_device
+{
+    register_t buffer;  // also used as LSB for divisor latch
+    struct IER IER;
+    struct IIR IIR;
+    struct FCR FCR;
+    struct LCR LCR;
+    struct MCR MCR;
+    struct LSR LSR;
+    struct MSR MSR;
+    register_t scratch;
+};
+
+
+// setup functions (wrappers)
+void usart_set_baudrate(uint16_t baudrate);
+void usart_set_parity(int mode);
+void usart_set_stop_bits(int count);
+void usart_set_word_length(int length);
+void usart_set_autoflow(int mode);
+
+inline void usart_init(uint16_t baudrate, int parity, int stop_bits); 
+
+void usart_transmit(uint8_t data);
+uint8_t usart_receive();
+
+int usart_write(uint8_t *data, size_t size);
+int usart_read(uint8_t *buffer, size_t count);
+
+#endif // __USART__H__
diff --git a/sw/z80/kernel/include/login.h b/sw/z80/kernel/include/login.h
deleted file mode 100644
index 5fa4b5e..0000000
--- a/sw/z80/kernel/include/login.h
+++ /dev/null
@@ -1,23 +0,0 @@
-#ifndef LOGIN_H
-#define LOGIN_H
-
-#include "types.h"
-
-#define LOGIN_PC    // TODO find an address in ROM, to perform jumps
-
-#define PWD_ADDR // TODO find an address in ROM, password
-#define PWD_SIZE 8
-
-/*
-*   It returns 1 if succeded, otherwise 0
-*/
-
-int8_t authenticate(const char *pwd);
-
-/*
-*   It sets the password in the ROM space, maximum 8 characters
-*/
-
-void set_pwd(const char *pwd);
-
-#endif
\ No newline at end of file
diff --git a/sw/z80/kernel/include/memory.h b/sw/z80/kernel/include/memory.h
new file mode 100644
index 0000000..5bca5a5
--- /dev/null
+++ b/sw/z80/kernel/include/memory.h
@@ -0,0 +1,48 @@
+#ifndef __MEMORY_H__
+#define __MEMORY_H__
+
+#include "types.h"
+#include "devices.h"
+
+/* maximum number of pages on the system */
+#define PAGES_MAX_COUNT 32
+
+/* in our system there are only 16 pages since only 64KB can be addressed
+ * to optimize the memory management in ROM and RAM only pages from this set
+ * shall be used
+ */
+// ROM
+#define ADDR_PAGE_0  0x0000
+#define ADDR_PAGE_1  0x1000
+#define ADDR_PAGE_2  0x2000
+#define ADDR_PAGE_3  0x3000
+// IOSPACE
+#define ADDR_PAGE_4  0x4000
+#define ADDR_PAGE_5  0x5000
+#define ADDR_PAGE_6  0x6000
+#define ADDR_PAGE_7  0x7000
+// RAM
+#define ADDR_PAGE_8  0x8000
+#define ADDR_PAGE_9  0x9000
+#define ADDR_PAGE_10 0xA000
+#define ADDR_PAGE_11 0xB000
+#define ADDR_PAGE_12 0xC000
+#define ADDR_PAGE_13 0xD000
+#define ADDR_PAGE_14 0xE000
+#define ADDR_PAGE_15 0xF000
+
+struct page
+{
+	uint used :1;
+	uint8_t pid;     // process owner of the page
+    uint16_t addr;   // physical address
+};
+
+extern struct page pages_table[PAGES_MAX_COUNT];
+
+int mmu_write_table(void);
+
+int page_map(int page, int pid, uint16_t addr);
+int page_unmap(int page);
+
+#endif // __MEMORY_H__
\ No newline at end of file
diff --git a/sw/z80/kernel/include/process.h b/sw/z80/kernel/include/process.h
new file mode 100644
index 0000000..ffd39e7
--- /dev/null
+++ b/sw/z80/kernel/include/process.h
@@ -0,0 +1,42 @@
+#ifndef __PROCESS_H__
+#define __PROCESS_H__
+
+#include "types.h"
+
+ /* maximum number of processes (i.e. pages in ram)
+  * since each program can use only one page in ram
+  */
+#define PROC_COUNT 2 
+
+struct executable
+{
+	void *text;
+	size_t text_size;
+	void *bss;
+	size_t bss_size;
+}
+
+struct process
+{
+    uint blocked :1;	// process is waiting for hardware or locked
+    uint running :1;	// pid is used
+    uint pages[4];		// pages used by the process
+    // TODO: implement quick callback?
+};
+
+/* 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];
+
+static pid_t newpid(void);
+
+int fork(void);
+int exec(char *path, char *args);
+int spawn(char *path, char *args);
+
+pid_t getpid(void);
+int kill(pid_t pid);
+
+#endif // __PROCESS_H__
diff --git a/sw/z80/kernel/include/progman.h b/sw/z80/kernel/include/progman.h
deleted file mode 100644
index b59e14a..0000000
--- a/sw/z80/kernel/include/progman.h
+++ /dev/null
@@ -1,109 +0,0 @@
-#ifndef PROGRAM_MAN
-#define PROGRAM_MAN
-
-#include "types.h"
-
-#define PROG_0 0x0
-#define PROG_1 0x1
-
-#define PROG_VSTART 0x1000
-#define PROG_0_PREFIX 0xA000
-#define PROG_1_PREFIX 0xC000
-
-#define PROG_0_INFO     // TODO
-#define PROG_1_INFO     // TODO find a space in the ram
-
-struct prog_status {
-
-    // The program is in execution
-
-    uint8_t running:1;
-
-    // The program is executing its quit callback
-
-    uint8_t exiting:1;
-
-    uint8_t unused:6;  // TODO, find a usage for these bits
-}:
-
-struct prog_data {
-
-    struct prog_status status;
-
-    /*
-    *   The following addresses are needed to map 
-    *   map the usable memory for dynamic allocations
-    */
-
-    // Virtual address of the heap
-
-    uint8_t heap_addr:12;
-
-    // Virtual address of the stack limit
-
-    uint8_t stack_limit:12;
-
-    /*
-    *   Function called when the program exits normally
-    */
-
-    void (*quit_cb)(void);   // 16
-};
-
-/*
-*   Initialize the program manager system
-*/
-
-void progman_init();
-
-/*  
-*   Check if it can start a new program
-*   If it succedes, the program id is returned,
-*   otherwise it is returned an error number
-*
-*   ! Disable virtual addresses when this function is called
-*/
-
-#define PROG_REQ_FULL -1
-
-int8_t prog_req();
-
-/*
-*   It allocates a program in the RAM
-*   To obtain the right id call prog_req() first
-*   Basic informations must be allocated and referenced by a program_base struct
-*
-*   ! Disable virtual addresses when this function is called
-*/
-
-struct prog_space {
-
-    void * inst_set;    // pointer to the instructions set
-    size_t inst_size;   // size of the instructions set
-    void * bss_data;    // pointer to the bss/data space
-    size_t data_size;   // size of the bss/data space
-};
-
-void prog_alloc(int8_t id, struct prog_data *data, const struct prog_space *space);
-
-/*
-*   It jumps the program counter to the given one
-*/
-
-void prog_exec(int8_t id, struct prog_data *data);
-
-/*
-*   It sets a quit callback
-*/
-
-void prog_0_set_qcb(void (*callback)(void));
-void prog_1_set_qcb(void (*callback)(void));
-
-/*
-*   It quits a program, if a callback is set, it will be called
-*/
-
-void prog_0_quit(uint8_t force);
-void prog_1_quit(uint8_t force);
-
-#endif
\ No newline at end of file
diff --git a/sw/z80/kernel/include/sysexe.h b/sw/z80/kernel/include/sysexe.h
deleted file mode 100644
index 9c13c09..0000000
--- a/sw/z80/kernel/include/sysexe.h
+++ /dev/null
@@ -1,55 +0,0 @@
-#ifndef SYS_EXE
-#define SYS_EXE
-
-#define SYS_EXEC_ADDR // TODO find an address in Kernel space
-
-struct sys_progman {
-
-    // program 0 enabled
-
-    uint8_t prog_0_enabled:1;
-
-    // program 1 enabled
-
-    /*
-    *   Obs: A program is enabled when its space is allocated 
-    *        and its virtual program counter is stored in 
-    *        the hardware or in the silent_pc.
-    *        An enabled program is not necessarly running, it 
-    *        could be paused too.
-    */
-
-    uint8_t prog_1_enabled:1;
-
-    // running's program id
-
-    uint8_t prog_running:1;
-};
-
-struct sys_exec {
-
-    /*
-    *   Virtual addresses are activated
-    */
-
-    uint8_t virtual_addr:1;
-
-    struct sys_progman progman;
-
-    /*
-    *   The silent_pc is the place designed to store the 
-    *   program counter of the program that's not running
-    */
-
-    uint8_t silent_pc:12;
-};
-
-/*
-*   Function to access informations
-*/
-
-uint8_t vaddr_enabled();
-
-struct sys_progman * sys_prog_data(struct sys_progman *data);
-
-#endif
\ No newline at end of file
diff --git a/sw/z80/kernel/include/types.h b/sw/z80/kernel/include/types.h
index 552b7e9..44df3eb 100644
--- a/sw/z80/kernel/include/types.h
+++ b/sw/z80/kernel/include/types.h
@@ -3,11 +3,14 @@
 
 #define register_t  volatile unsigned char
 
+#define uint 		unsigned int
+
 #define int8_t      char
 #define uint8_t     unsigned char
 #define int16_t     int
-#define uint16_t    unsigned int
+#define uint16_t    unsigned long int
 
 #define size_t      uint16_t
+#define pid_t 		uint8_t
 
 #endif
diff --git a/sw/z80/kernel/include/usart.h b/sw/z80/kernel/include/usart.h
deleted file mode 100644
index 3e5c070..0000000
--- a/sw/z80/kernel/include/usart.h
+++ /dev/null
@@ -1,149 +0,0 @@
-#ifndef __USART_H__
-#define __USART_H__
-
-#include "types.h"
-#include "devices.h"
-
-#include "string.h"
-
-// baudrate clock divisors 
-// values from TL16C550C datasheet (table 9 for 1.8432 MHz crystal)
-#define USART_BAUDRATE_50       2304
-#define USART_BAUDRATE_75       1536
-#define USART_BAUDRATE_110      1047
-#define USART_BAUDRATE_134_5    857
-#define USART_BAUDRATE_150      768
-#define USART_BAUDRATE_300      384
-#define USART_BAUDRATE_600      192
-#define USART_BAUDRATE_1200     96
-#define USART_BAUDRATE_1800     64
-#define USART_BAUDRATE_2000     58
-#define USART_BAUDRATE_2400     48
-#define USART_BAUDRATE_3600     32
-#define USART_BAUDRATE_4800     24
-#define USART_BAUDRATE_7200     16
-#define USART_BAUDRATE_9600     12
-#define USART_BAUDRATE_19200    6
-#define USART_BAUDRATE_38400    3
-#define USART_BAUDRATE_56000    3
-
-// parity
-#define USART_PARITY_NONE       0
-#define USART_PARITY_EVEN       1
-#define USART_PARITY_ODD        2
-
-// stop bits
-#define USART_STOP_BITS_1       10
-#define USART_STOP_BITS_15      15
-#define USART_STOP_BITS_2       20
-
-// word lenght
-#define USART_WORD_LENGTH_5     0
-#define USART_WORD_LENGTH_6     1
-#define USART_WORD_LENGTH_7     2
-#define USART_WORD_LENGTH_8     3
-
-// autoflow
-#define USART_AUTOFLOW_ALL      3
-#define USART_AUTOFLOW_CTS      2
-#define USART_AUTOFLOW_OFF      0
-
-
-/* this structure is only for internal usage */
-struct _usart_device
-{
-    register_t buffer;  // also used as LSB for divisor latch
-
-    struct IER 
-    {
-        volatile int received_data_interrupt :1;
-        volatile int transmitter_empty_interrupt :1;
-        volatile int receiver_line_status_interrupt :1;
-        volatile int modem_status_interrupt :1;
-        volatile int reserved :4;
-    } IER;
-
-    struct IIR
-    {
-        volatile int interrupt_pending :1;
-        volatile int interrupt_id :3;
-        volatile int reserved :2;
-        volatile int fifos :2;
-    } IIR;
-
-    struct FCR
-    {
-        volatile int fifo_enable :1;
-        volatile int receiver_fifo_rst :1;
-        volatile int trasmitter_fifo_rst :1;
-        volatile int dma_mode_select :1;
-        volatile int reserved :1;
-        volatile int receiver_trigger :2;
-    } FCR;
-
-    struct LCR
-    {
-        volatile int word_length :2;
-        volatile int stop_bits :1;
-        volatile int parity :1;
-        volatile int even_parity :1;
-        volatile int stick_parity :1;
-        volatile int break_control :1;
-        volatile int divisor_latch_access :1;
-    } LCR;
-
-    struct MCR
-    {
-        volatile int data_terminal_ready :1;
-        volatile int request_to_send :1;
-        volatile int out1;
-        volatile int out2;
-        volatile int loop;
-        volatile int autoflow :1;
-        volatile int reserved :2;
-    } MCR;
-
-    struct LSR 
-    {
-        volatile int data_ready :1;
-        volatile int overrun_error :1;
-        volatile int parity_error :1;
-        volatile int framing_error :1;
-        volatile int break_interrupt :1;
-        volatile int transmitter_holder_empty :1;
-        volatile int transmitter_empty :1;
-        volatile int fifo_recv_error :1;
-    } LSR;
-
-    struct MSR
-    {
-        volatile int delta_cts :1;
-        volatile int delta_data_set_ready :1;
-        volatile int trailing_edge_ring_indicator :1;
-        volatile int delta_data_carrier_detect :1;
-        volatile int clear_to_send :1;
-        volatile int data_set_ready :1;
-        volatile int ring_indicator :1;
-        volatile int data_carrier_detect :1;
-    } MSR;
-
-    register_t scratch;
-};
-
-
-// setup functions (wrappers)
-void usart_set_baudrate(uint16_t baudrate);
-void usart_set_parity(int mode);
-void usart_set_stop_bits(int count);
-void usart_set_word_length(int length);
-void usart_set_autoflow(int mode);
-
-inline void usart_init(uint16_t baudrate, int parity, int stop_bits); 
-
-void usart_transmit(uint8_t data);
-uint8_t usart_receive();
-
-int usart_write(uint8_t *data, size_t size);
-int usart_read(uint8_t *buffer, size_t count);
-
-#endif // __USART__H__