/**
** @file	kdefs.h
**
** @author	CSCI-452 class of 20245
**
** @brief	Kernel-only declarations.
*/

#ifndef KDEFS_H_
#define KDEFS_H_

// debugging macros
#include <debug.h>

/*
** General (C and/or assembly) definitions
*/

// page sizes
#define	SZ_PAGE          NUM_4KB
#define SZ_BIGPAGE       NUM_4MB

// kernel stack size (bytes)
#define	N_KSTKPAGES      1 
#define SZ_KSTACK        (N_KSTKPAGES * SZ_PAGE)

// user stack size
#define N_USTKPAGES      2
#define SZ_USTACK        (N_USTKPAGES * SZ_PAGE)

// declarations for modulus checking of (e.g.) sizes and addresses

#define MOD4_BITS        0x00000003
#define MOD4_MASK        0xfffffffc
#define MOD4_INC         0x00000004
#define MOD4_SHIFT       2

#define MOD16_BITS       0x0000000f
#define MOD16_MASK       0xfffffff0
#define MOD16_INC        0x00000010
#define MOD16_SHIFT      4

#define	MOD1K_BITS       0x000003ff
#define MOD1K_MASK       0xfffffc00
#define MOD1K_INC        0x00000400
#define MOD1K_SHIFT      10

#define	MOD4K_BITS       0x00000fff
#define MOD4K_MASK       0xfffff000
#define MOD4K_INC        0x00001000
#define MOD4K_SHIFT      12

#define	MOD1M_BITS       0x000fffff
#define MOD1M_MASK       0xfff00000
#define MOD1M_INC        0x00100000
#define MOD1M_SHIFT      20

#define	MOD1G_BITS       0x3fffffff
#define MOD1G_MASK       0xc0000000
#define MOD1G_INC        0x40000000
#define MOD1G_SHIFT      30

#ifndef ASM_SRC

/*
** Start of C-only definitions
*/

// unit conversion macros
#define B_TO_KB(x)      (((uint_t)(x))>>10)
#define B_TO_MB(x)      (((uint_t)(x))>>20)
#define B_TO_GB(x)      (((uint_t)(x))>>30)

#define KB_TO_B(x)      (((uint_t)(x))<<10)
#define KB_TO_MB(x)     (((uint_t)(x))>>10)
#define KB_TO_GB(x)     (((uint_t)(x))>>20)

#define MB_TO_B(x)      (((uint_t)(x))<<20)
#define MB_TO_KB(x)     (((uint_t)(x))<<10)
#define MB_TO_GB(x)     (((uint_t)(x))>>10)

#define GB_TO_B(x)      (((uint_t)(x))<<30)
#define GB_TO_KB(x)     (((uint_t)(x))<<20)
#define GB_TO_MB(x)     (((uint_t)(x))<<10)

// potetially useful compiler attributes
#define ALIGN(x)        __attribute__((__aligned__(x)))
#define PACKED          __attribute__((__packed__))

/*
** Utility macros
*/

//
// macros to clear data structures
//
// these are usable for clearing single-valued data items (e.g.,
// a PCB, etc.)
#define CLEAR(v)        memclr( &v, sizeof(v) )
#define CLEAR_PTR(p)    memclr( p, sizeof(*p) )

//
// macros for access registers and system call arguments
//

// REG(pcb,x) -- access a specific register in a process context
#define REG(pcb,x)  ((pcb)->context->x)

// RET(pcb) -- access return value register in a process context
#define RET(pcb)    ((pcb)->context->eax)

// ARG(pcb,n) -- access argument #n from the indicated process
//
// ARG(pcb,0) --> return address
// ARG(pcb,1) --> first parameter
// ARG(pcb,2) --> second parameter
// etc.
//
// ASSUMES THE STANDARD 32-BIT ABI, WITH PARAMETERS PUSHED ONTO THE
// STACK.  IF THE PARAMETER PASSING MECHANISM CHANGES, SO MUST THIS!
#define ARG(pcb,n)  ( ( (uint32_t *) (((pcb)->context) + 1) ) [(n)] )

/*
** Types
*/

/*
** Globals
*/

// general-purpose character buffer
extern char b256[256];

// buffer for use by PANIC() macro
extern char b512[512];

// kernel stack
extern uint8_t kstack[SZ_KSTACK];

/*
** Prototypes
*/

#endif  /* !ASM_SRC */

#endif