source: soft/giet_vm/libs/stdio.c @ 252

//////////////////////////////////////////////////////////////////////////////////
// File     : stdio.c         
// Date     : 01/04/2010
// Author   : alain greiner & Joel Porquet
// Copyright (c) UPMC-LIP6
///////////////////////////////////////////////////////////////////////////////////
// The stdio.c and stdio.h files are part of the GIET_VM nano-kernel.
// This library contains all user-level functions that contain a system call
// to access protected or shared ressources.
///////////////////////////////////////////////////////////////////////////////////

#include <stdarg.h>
#include <stdio.h>

#define SYSCALL_PROCID          0x00
#define SYSCALL_PROCTIME        0x01
#define SYSCALL_TTY_WRITE       0x02
#define SYSCALL_TTY_READ        0x03
#define SYSCALL_TIMER_START     0x04
#define SYSCALL_TIMER_STOP      0x05
#define SYSCALL_GCD_WRITE       0x06
#define SYSCALL_GCD_READ        0x07
#define SYSCALL_HEAP_INFO       0x08
#define SYSCALL_PROC_TASK_ID    0x09
#define SYSCALL_GLOBAL_TASK_ID  0x0A
#define SYSCALL_CTX_SWITCH      0x0D
#define SYSCALL_EXIT            0x0E
#define SYSCALL_PROC_NUMBER     0x0F
#define SYSCALL_FB_SYNC_WRITE   0x10
#define SYSCALL_FB_SYNC_READ    0x11
#define SYSCALL_FB_WRITE        0x12
#define SYSCALL_FB_READ         0x13
#define SYSCALL_FB_COMPLETED    0x14
#define SYSCALL_IOC_WRITE       0x15
#define SYSCALL_IOC_READ        0x16
#define SYSCALL_IOC_COMPLETED   0x17
#define SYSCALL_IOC_BLOCK_SIZE  0x18
#define SYSCALL_VOBJ_GET_VBASE  0x1A
#define SYSCALL_NIC_WRITE       0x1B
#define SYSCALL_NIC_READ        0x1C
#define SYSCALL_NIC_COMPLETED   0x1D

//////////////////////////////////////////////////////////////////////////////////
// sys_call()
// This generic C function is used to implement all system calls.
// It writes the system call arguments in the proper registers,
// and tells GCC what has been modified by system call execution.
//////////////////////////////////////////////////////////////////////////////////
static inline unsigned int sys_call(unsigned int call_no,
        unsigned int arg_0, 
        unsigned int arg_1, 
        unsigned int arg_2, 
        unsigned int arg_3) {
    register unsigned int reg_no_and_output asm("v0") = call_no;
    register unsigned int reg_a0 asm("a0") = arg_0;
    register unsigned int reg_a1 asm("a1") = arg_1;
    register unsigned int reg_a2 asm("a2") = arg_2;
    register unsigned int reg_a3 asm("a3") = arg_3;

    asm volatile(
            "syscall"
            : "=r" (reg_no_and_output)  /* output argument */
            : "r" (reg_a0),             /* input arguments */
            "r" (reg_a1),
            "r" (reg_a2),
            "r" (reg_a3),
            "r" (reg_no_and_output)
            : "memory",
            /* These persistant registers will be saved on the stack by the
             * compiler only if they contain relevant data. */
            "at",
            "v1",
            "ra",
            "t0",
            "t1",
            "t2",
            "t3",
            "t4",
            "t5",
            "t6",
            "t7",
            "t8",
            "t9"
               );
    return reg_no_and_output;
}

/////      MIPS32 related system calls  /////

////////////////////////////////////////////////////////////////////////////////////
// giet_procid()
////////////////////////////////////////////////////////////////////////////////////
// This function returns the processor identifier.
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_procid() {
    return sys_call(SYSCALL_PROCID, 0, 0, 0, 0);
}


////////////////////////////////////////////////////////////////////////////////////
// giet_proctime()
////////////////////////////////////////////////////////////////////////////////////
// This function returns the local processor time (clock cycles since boot)
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_proctime() 
{
    return sys_call(SYSCALL_PROCTIME, 0, 0, 0, 0);
}


//////     TTY device related system calls /////

////////////////////////////////////////////////////////////////////////////////////
// giet_tty_putc()
////////////////////////////////////////////////////////////////////////////////////
// This function displays a single ascii character on a terminal.
// The terminal index must be defined in the task context in the boot phase.
// It doesn't use the TTY_PUT_IRQ interrupt, and the associated kernel buffer.
// - Returns 1 if the character has been written, 0 otherwise.
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_tty_putc(char byte) 
{
    return sys_call(SYSCALL_TTY_WRITE, (unsigned int) (&byte), 1, 0, 0);
}


////////////////////////////////////////////////////////////////////////////////////
// giet_tty_puts()
////////////////////////////////////////////////////////////////////////////////////
// This function displays a string on a terminal.
// The terminal index must be defined in the task context in the boot phase.
// The string must be terminated by a NUL character.
// It doesn't use the TTY_PUT_IRQ interrupt, and the associated kernel buffer.
// - Returns the number of written characters.
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_tty_puts(char * buf) 
{
    unsigned int length = 0;
    while (buf[length] != 0) { length++; }
    return sys_call(SYSCALL_TTY_WRITE, (unsigned int) buf, length, 0, 0);
}


////////////////////////////////////////////////////////////////////////////////////
// giet_tty_putw()
////////////////////////////////////////////////////////////////////////////////////
// This function displays the value of a 32-bit word with decimal characters.
// The terminal index must be defined in the task context in the boot phase.
// It doesn't use the TTY_PUT_IRQ interrupt, and the associated kernel buffer.
// Returns the number of written characters (should be equal to ten).
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_tty_putw(unsigned int val) 
{
    char buf[10];
    unsigned int i;
    for (i = 0; i < 10; i++) 
    {
        buf[9 - i] = (val % 10) + 0x30;
        val = val / 10;
    }
    return sys_call(SYSCALL_TTY_WRITE, (unsigned int) buf, 10, 0, 0);
}


////////////////////////////////////////////////////////////////////////////////////
// giet_tty_getc()
////////////////////////////////////////////////////////////////////////////////////
// This blocking function fetches a single ascii character from a terminal.
// The terminal index must be defined in the task context in the boot phase.
// It uses the IRQ_GET interrupt, and the associated kernel buffer.
// - Returns 0 when completed.
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_tty_getc(char * byte) 
{
    unsigned int ret = 0;
    while (ret == 0) 
    {
        ret = sys_call(SYSCALL_TTY_READ, (unsigned int)byte, 1, 0, 0);
    }
    return 0;
}


////////////////////////////////////////////////////////////////////////////////////
// giet_tty_gets()
////////////////////////////////////////////////////////////////////////////////////
// This blocking function fetches a string from a terminal to a fixed length buffer.
// The terminal index must be defined in the task context in the boot phase.
// It uses the TTY_GET_IRQ interrupt, anf the associated kernel buffer.
// - Returns 0 when completed.
// - Up to (bufsize - 1) characters (including the non printable characters)
//   will be copied into buffer, and the string is always completed by a NUL
//   character.
// - The <LF> character is interpreted, and the function close the string with a
//   NUL character if <LF> is read.
// - The <DEL> character is interpreted, and the corresponding character(s) are
//   removed from the target buffer.
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_tty_gets( char*        buf, 
                            unsigned int bufsize) 
{
    unsigned int ret;
    unsigned char byte;
    unsigned int index = 0;

    while (index < (bufsize - 1)) 
    {
        do { ret = sys_call(SYSCALL_TTY_READ, (unsigned int) (&byte), 1, 0, 0); } 
        while (ret != 1);

        if (byte == 0x0A)  /* LF */
        {
            break; 
        }
        else if ((byte == 0x7F) && (index > 0))  /* DEL */
        {
            index--; 
        }
        else 
        {
            buf[index] = byte;
            index++;
        }
    }
    buf[index] = 0;
    return 0;
}


////////////////////////////////////////////////////////////////////////////////////
// giet_tty_getw()
////////////////////////////////////////////////////////////////////////////////////
// This blocking function fetches a string of decimal characters (most
// significant digit first) to build a 32-bit unsigned integer.
// The terminal index must be defined in the task context in the boot phase.
// It uses the TTY_GET_IRQ interrupt, anf the associated kernel buffer.
// - Returns necessarily 0 when completed.
//
// - The non-blocking system function _tty_read_irq is called several times,
//   and the decimal characters are written in a 32 characters buffer until a
//   <LF> character is read.
// - The <DEL> character is interpreted, and previous characters can be
//   cancelled. All others characters are ignored.
// - When the <LF> character is received, the string is converted to an
//   unsigned int value. If the number of decimal digit is too large for the 32
//   bits range, the zero value is returned.
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_tty_getw(unsigned int * val) 
{
    unsigned char buf[32];
    unsigned char byte;
    unsigned int save = 0;
    unsigned int dec = 0;
    unsigned int done = 0;
    unsigned int overflow = 0;
    unsigned int max = 0;
    unsigned int i;
    unsigned int ret;

    while (done == 0) 
    {
        do { ret = sys_call(SYSCALL_TTY_READ, (unsigned int) (&byte), 1, 0, 0); } 
        while (ret != 1);

        if ((byte > 0x2F) && (byte < 0x3A))  /* decimal character */
        {
            buf[max] = byte;
            max++;
            giet_tty_putc(byte);
        }
        else if ((byte == 0x0A))   /* LF */
        {
            done = 1;
        }
        else if (byte == 0x7F)   /* DEL */
        {
            if (max > 0) 
            {
                max--;      /* cancel the character */
                giet_tty_putc(0x08);
                giet_tty_putc(0x20);
                giet_tty_putc(0x08);
            }
        }
        if (max == 32)  /* decimal string overflow */
        {
            for (i = 0; i < max; i++) 
            {
                /* cancel the string */
                giet_tty_putc(0x08);
                giet_tty_putc(0x20);
                giet_tty_putc(0x08);
            }
            giet_tty_putc(0x30);
            *val = 0;      /* return 0 value */
            return 0;
        }
    }

    /* string conversion */
    for (i = 0; i < max; i++) 
    {
        dec = dec * 10 + (buf[i] - 0x30);
        if (dec < save)  overflow = 1; 
        save = dec;
    }

    /* check overflow */
    if (overflow == 0) 
    {
        *val = dec; /* return decimal value */
    }
    else 
    {
        for (i = 0; i < max; i++) 
        {
            /* cancel the string */
            giet_tty_putc(0x08);
            giet_tty_putc(0x20);
            giet_tty_putc(0x08);
        }
        giet_tty_putc(0x30);
        *val = 0;         /* return 0 value */
    }
    return 0;
}


////////////////////////////////////////////////////////////////////////////////////
// giet_tty_printf()
////////////////////////////////////////////////////////////////////////////////////
// This function is a simplified version of the mutek_printf() function.
// The terminal index must be defined in the calling task context.
// It doesn't use the IRQ_PUT interrupt, and the associated kernel buffer.
// Only a limited number of formats are supported:
//   - %d : signed decimal
//   - %u : unsigned decimal
//   - %x : hexadecimal
//   - %c : char
//   - %s : string
// - Returns 0 if success, > 0 if error.
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_tty_printf(char * format, ...) 
{
    va_list ap;
    va_start(ap, format);
    unsigned int ret;

printf_text:

    while (*format) 
    {
        unsigned int i;
        for (i = 0; format[i] && format[i] != '%'; i++);
        if (i) 
        {
            ret = sys_call(SYSCALL_TTY_WRITE, (unsigned int) format, i, 0, 0);
            if (ret != i)  return 1; /* return error */ 
            format += i;
        }
        if (*format == '%') 
        {
            format++;
            goto printf_arguments;
        }
    }

    va_end(ap);
    return 0;

printf_arguments:

    {
        int val = va_arg(ap, long);
        char buf[20];
        char * pbuf;
        unsigned int len = 0;
        static const char HexaTab[] = "0123456789ABCDEF";
        unsigned int i;

        switch (*format++) {
            case ('c'):             /* char conversion */
                len = 1;
                buf[0] = val;
                pbuf = buf;
                break;
            case ('d'):             /* decimal signed integer */
                if (val < 0) {
                    val = -val;
                    ret = sys_call(SYSCALL_TTY_WRITE, (unsigned int)"-", 1, 0, 0);
                    if (ret != 1) {
                        return 1; /* return error */
                    }
                }
            case ('u'):             /* decimal unsigned integer */
                for(i = 0; i < 10; i++) {
                    buf[9 - i] = HexaTab[val % 10];
                    if (!(val /= 10)) {
                        break;
                    }
                }
                len =  i + 1;
                pbuf = &buf[9 - i];
                break;
            case ('x'):             /* hexadecimal integer */
                ret = sys_call(SYSCALL_TTY_WRITE, (unsigned int) "0x", 2, 0, 0);
                if (ret != 2) {
                    return 1; /* return error */
                }
                for(i = 0; i < 8; i++) {
                    buf[7 - i] = HexaTab[val % 16U];
                    if (!(val /= 16U)) {
                        break;
                    }
                }
                len =  i + 1;
                pbuf = &buf[7 - i];
                break;
            case ('s'):             /* string */
                {
                    char * str = (char *) val;
                    while (str[len]) {
                        len++;
                    }
                    pbuf = (char *) val;
                }
                break;
            default:
                goto printf_text;
        }

        ret = sys_call(SYSCALL_TTY_WRITE, (unsigned int) pbuf, len, 0, 0);
        if (ret != len) {
            return 1;
        }
        goto printf_text;
    }
}


/////  TIMER related system calls ////// 

//////////////////////////////////////////////////////////////////////////////////
// giet_timer_start()
//////////////////////////////////////////////////////////////////////////////////
// This function activates the private user timer allocated to the calling task
// in the boot phase.
// - Returns 0 if success, > 0 if error.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_timer_start() {
    return sys_call(SYSCALL_TIMER_START, 0, 0, 0, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_timer_stop()
//////////////////////////////////////////////////////////////////////////////////
// This function activates the user timer allocated to the calling task.
// - Returns 0 if success, > 0 if error.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_timer_stop() {
    return sys_call(SYSCALL_TIMER_STOP, 0, 0, 0, 0);
}


/////  GCD (Greatest Common Divider) related system calls

#define GCD_OPA     0
#define GCD_OPB     1
#define GCD_START   2
#define GCD_STATUS  3

//////////////////////////////////////////////////////////////////////////////////
// giet_gcd_set_opa()
//////////////////////////////////////////////////////////////////////////////////
// This function sets the operand A in the GCD coprocessor.
// - Returns 0 if success, > 0 if error.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_gcd_set_opa(unsigned int val) {
    return sys_call(SYSCALL_GCD_WRITE, GCD_OPA, val, 0, 0);
}


//////////////////////////////////////////////////////////////////////////////////
//     giet_gcd_set_opb()
//////////////////////////////////////////////////////////////////////////////////
// This function sets operand B in the GCD coprocessor.
// - Returns 0 if success, > 0 if error.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_gcd_set_opb(unsigned int val) {
    return sys_call(SYSCALL_GCD_WRITE, GCD_OPB, val, 0, 0);
}


//////////////////////////////////////////////////////////////////////////////////
//     giet_gcd_start()
//////////////////////////////////////////////////////////////////////////////////
// This function starts the computation in the GCD coprocessor.
// - Returns 0 if success, > 0 if error.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_gcd_start() {
    return sys_call(SYSCALL_GCD_WRITE, GCD_START, 0, 0, 0);
}


//////////////////////////////////////////////////////////////////////////////////
//     giet_gcd_get_status()
//////////////////////////////////////////////////////////////////////////////////
// This function gets the status fromn the GCD coprocessor.
// - The value is 0 when the coprocessor is idle (computation completed).
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_gcd_get_status(unsigned int * val) {
    return sys_call(SYSCALL_GCD_READ, GCD_STATUS, (unsigned int) val, 0, 0);
}


//////////////////////////////////////////////////////////////////////////////////
//     giet_gcd_get_result()
//////////////////////////////////////////////////////////////////////////////////
// This function gets the result of the computation from the GCD coprocessor.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_gcd_get_result(unsigned int * val) {
    return sys_call(SYSCALL_GCD_READ, GCD_OPA, (unsigned int) val, 0, 0);
}


///// Block device related system calls  /////

//////////////////////////////////////////////////////////////////////////////////
//     giet_ioc_write()
//////////////////////////////////////////////////////////////////////////////////
// Transfer data from a memory buffer to a file on the block_device.
//     lba    : Logical Block Address (first block index)
//     buffer : base address of the memory buffer
//     count  : number of blocks to be transfered
// - Returns 0 if success, > 0 if error (e.g. memory buffer not in user space).
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_ioc_write( unsigned int lba, void * buffer, unsigned int count) {
    return sys_call(SYSCALL_IOC_WRITE, lba, (unsigned int) buffer, count, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_ioc_read()
//////////////////////////////////////////////////////////////////////////////////
// Transfer data from a file on the block_device to a memory buffer.
//     lba    : Logical Block Address (first block index)
//     buffer : base address of the memory buffer
//     count  : number of blocks to be transfered
// - Returns 0 if success, > 0 if error (e.g. memory buffer not in user space).
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_ioc_read(unsigned int lba, void * buffer, unsigned int count) {
    return sys_call(SYSCALL_IOC_READ, lba, (unsigned int) buffer, count, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_ioc_completed()
//////////////////////////////////////////////////////////////////////////////////
// This blocking function returns 0 when the I/O transfer is
// successfully completed, and returns 1 if an address error has been detected.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_ioc_completed() {
    return sys_call(SYSCALL_IOC_COMPLETED, 0, 0, 0, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_ioc_block_size()
//////////////////////////////////////////////////////////////////////////////////
// This blocking function returns the block_size (in bytes) of the block device
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_ioc_block_size() {
    return sys_call(SYSCALL_IOC_BLOCK_SIZE, 0, 0, 0, 0);
}


/////  Frame buffer device related system calls  /////

//////////////////////////////////////////////////////////////////////////////////
// giet_fb_sync_write()
//////////////////////////////////////////////////////////////////////////////////
// This blocking function use a memory copy strategy to transfer data from a
// user buffer to the frame buffer device in kernel space.
//     offset : offset (in bytes) in the frame buffer
//     buffer : base address of the memory buffer
//     length : number of bytes to be transfered
// - Returns 0 if success, > 0 if error (e.g. memory buffer not in user space).
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_fb_sync_write(unsigned int offset, void * buffer, unsigned int length) {
    return sys_call(SYSCALL_FB_SYNC_WRITE, offset, (unsigned int) buffer, length, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_fb_sync_read()
//////////////////////////////////////////////////////////////////////////////////
// This blocking function use a memory copy strategy to transfer data from the
// frame buffer device in kernel space to an user buffer.
//     offset : offset (in bytes) in the frame buffer
//     buffer : base address of the user buffer
//     length : number of bytes to be transfered
// - Returns 0 if success, > 0 if error (e.g. memory buffer not in user space).
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_fb_sync_read(unsigned int offset, void * buffer, unsigned int length) {
    return sys_call(SYSCALL_FB_SYNC_READ, offset, (unsigned int) buffer, length, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_fb_write()
//////////////////////////////////////////////////////////////////////////////////
// This non-blocking function use the DMA coprocessor to transfer data from a
// user buffer to the frame buffer device in kernel space.
// - offset : offset (in bytes) in the frame buffer
// - buffer : base address of the user buffer
// - length : number of bytes to be transfered
// The transfer completion is signaled by an IRQ, and must be tested by the
// fb_completed() function.
// - Returns 0 if success, > 0 if error (e.g. memory buffer not in user space).
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_fb_write(unsigned int offset, void * buffer, unsigned int length) {
    return sys_call(SYSCALL_FB_WRITE, offset, (unsigned int) buffer, length, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_fb_read()
//////////////////////////////////////////////////////////////////////////////////
// This non-blocking function use the DMA coprocessor to transfer data from the
// frame buffer device in kernel space to an user buffer.
// - offset : offset (in bytes) in the frame buffer
// - buffer : base address of the memory buffer
// - length : number of bytes to be transfered
// The transfer completion is signaled by an IRQ, and must be tested by the
// fb_completed() function.
// - Returns 0 if success, > 0 if error (e.g. memory buffer not in user space).
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_fb_read(unsigned int offset, void * buffer, unsigned int length) {
    return sys_call(SYSCALL_FB_READ, offset, (unsigned int) buffer, length, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_fb_completed()
//////////////////////////////////////////////////////////////////////////////////
// This blocking function returns when the transfer is completed.
// - Returns 0 if success, > 0 if error.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_fb_completed() {
    return sys_call(SYSCALL_FB_COMPLETED, 0, 0, 0, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_nic_write()
//////////////////////////////////////////////////////////////////////////////////
// This non-blocking function use the DMA coprocessor to transfer data from the
// NIC device to an user buffer.
// - offset : offset (in bytes) in the NIC
// - buffer : base address of the memory buffer
// - length : number of bytes to be transfered
// The transfer completion is signaled by an IRQ, and must be tested by the
// nic_completed() function.
// - Returns 0 if success, > 0 if error (e.g. memory buffer not in user space).
//////////////////////////////////////////////////////////////////////////////////

unsigned int giet_nic_write(unsigned int offset, void * buffer, unsigned int length) {
    return sys_call(SYSCALL_NIC_WRITE, offset, (unsigned int) buffer, length, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_nic_read()
//////////////////////////////////////////////////////////////////////////////////
// This non-blocking function use the DMA coprocessor to transfer data from the
// NIC device to an user buffer.
// - offset : offset (in bytes) in the NIC
// - buffer : base address of the memory buffer
// - length : number of bytes to be transfered
// The transfer completion is signaled by an IRQ, and must be tested by the
// nic_completed() function.
// - Returns 0 if success, > 0 if error (e.g. memory buffer not in user space).
//////////////////////////////////////////////////////////////////////////////////

unsigned int giet_nic_read(unsigned int offset, void * buffer, unsigned int length) {
    return sys_call(SYSCALL_NIC_READ, offset, (unsigned int) buffer, length, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_nic_completed()
//////////////////////////////////////////////////////////////////////////////////
// This blocking function returns when the transfer is completed.
// - Returns 0 if success, > 0 if error.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_nic_completed() {
    return sys_call(SYSCALL_NIC_COMPLETED, 0, 0, 0, 0);
}


///// Miscellaneous related system calls /////

//////////////////////////////////////////////////////////////////////////////////
// giet_vobj_get_vbase()
//////////////////////////////////////////////////////////////////////////////////
// This function writes in argument (vobj_vaddr) the virtual base address 
// of a vobj (defined in the mapping_info data structure), identified by 
// the two arguments (vspace_name and vobj_name).
// The (vobj_type) argument is redundant, and used for coherence checking.
// - Returns the address if success,  0 if error ( not defined or wrong type )
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_vobj_get_vbase(char * vspace_name, char * vobj_name, unsigned int vobj_type, unsigned int * vobj_vaddr) {
    return sys_call(SYSCALL_VOBJ_GET_VBASE, 
            (unsigned int) vspace_name,
            (unsigned int) vobj_name,
            (unsigned int) vobj_type,
            (unsigned int) vobj_vaddr);
}


////////////////////////////////////////////////////////////////////////////////////
// giet_proc_number()
////////////////////////////////////////////////////////////////////////////////////
// This function returns in the buffer argument the number of processors 
// in the cluster specified by the cluster_id argument.
// - Returns 0 if success, > 0 if error ( cluster index too large )
////////////////////////////////////////////////////////////////////////////////////
unsigned int giet_proc_number(unsigned int cluster_id, unsigned int * buffer) {
    return sys_call(SYSCALL_PROC_NUMBER, cluster_id, (unsigned int) buffer, 0, 0);
}


/////  Miscellaneous system calls /////

//////////////////////////////////////////////////////////////////////////////////
// giet_task_exit()
//////////////////////////////////////////////////////////////////////////////////
// This function stops execution of the calling task with a TTY message, 
// and enter an infinite loop.
// The task is blocked, but it still consume processor cycles ...
//////////////////////////////////////////////////////////////////////////////////
void giet_exit() {
    sys_call(SYSCALL_EXIT, 0, 0, 0, 0);
}


///////////////////////////////////////////////////////////////////////////////////
// giet_rand()
// This function returns a pseudo-random value derived from the processor cycle
// count. This value is comprised between 0 & 65535.
///////////////////////////////////////////////////////////////////////////////////
unsigned int giet_rand() {
    unsigned int x = sys_call(SYSCALL_PROCTIME, 0, 0, 0, 0);
    if ((x & 0xF) > 7) {
        return (x*x & 0xFFFF);
    }
    else {
        return (x*x*x & 0xFFFF);
    }
}


//////////////////////////////////////////////////////////////////////////////////
// giet_context_switch()
// The user task calling this function is descheduled and
// the processor is allocated to another task.
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_context_switch() {
    return sys_call(SYSCALL_CTX_SWITCH, 0, 0, 0, 0);
}

//////////////////////////////////////////////////////////////////////////////////
// giet_proc_task_id()
// This functions returns the local task id, i.e. the processor task id (ranging
// from 0 to n-1(p) for each processor if p has n tasks)
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_proc_task_id() {
    return sys_call(SYSCALL_PROC_TASK_ID, 0, 0, 0, 0);
}

//////////////////////////////////////////////////////////////////////////////////
// giet_heap_info()
// This function returns the base address and size of the current task's heap
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_heap_info(unsigned int * vaddr, unsigned int * length) {
    return sys_call(SYSCALL_HEAP_INFO, (unsigned int) vaddr, (unsigned int) length, 0, 0);
}


//////////////////////////////////////////////////////////////////////////////////
// giet_global_task_id()
// This functions returns the global task id, which is unique in all the giet
//////////////////////////////////////////////////////////////////////////////////
unsigned int giet_global_task_id() {
    return sys_call(SYSCALL_GLOBAL_TASK_ID, 0, 0, 0, 0);
}

// Local Variables:
// tab-width: 4
// c-basic-offset: 4
// c-file-offsets:((innamespace . 0)(inline-open . 0))
// indent-tabs-mode: nil
// End:
// vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4