/* LOADHIGH.H - contains macros, structures, prototypes and 
   global variables for LOADHIGH.C */

/* Macro to convert bytes to paragraphs */
#define topara(x) (((x) + 0xf) >> 4)

/* Make sure the FP_SEG macro is a valid lvalue */
#ifdef FP_SEG
#  undef FP_SEG
#endif

#define FP_SEG(x)  (*(((unsigned short *)&(x))+1))

/* typedefs for common DOS data types */
typedef unsigned char BYTE;
typedef unsigned short WORD;
typedef unsigned long DWORD;

/* memory control block */
struct MCB
{
   BYTE sig;
   WORD owner;
   WORD size;
   BYTE res[3];
   BYTE name[8];
};

/* Prototypes for the assembler functions */
WORD    DosAlloc(WORD paragraphs);              /* DOS func. 48h */
WORD    DosSetStrategy(WORD strat);             /* DOS func. 5801h */
int     DosSetUMBLink(int value);               /* DOS func. 5803h */
int     DosResize(WORD block, WORD newSize);    /* DOS func. 4ah */
void    DosFree(WORD block);                    /* DOS func. 49h */
WORD    GetFirstMCB(void);

/* far memory version of memcmp() */
int     farmemcmp(void far *s1, void far *s2, size_t nbytes);

/* These variables are used to save the DOS malloc strategy
   and UMB link state, to restore them when the program terminates */
WORD    old_link, old_strat;
int     umbLink; /* This variable holds the current state of the UMB link */

char   *newcmdline;      /* New command line */

/* characters that delimit the file name */
char   *filename_delimitors = " \t\r\n/;,+=<>|[]\"";

/* This array will contain the memory blocks that the new program can't use */
int     allocatedBlocks = 0;
WORD   *block;

char    *filename;

int     swShrink;       /* Flag: was the 'S' switch present? */
int     swLoad;         /* Flag: was the 'L' switch present? */
int     loadfix_flag;   /* Flag: are we processing LOADFIX or LOADHIGH? */
int     upper_flag;     /* Flag: should the program be loaded high? */

/* UMB region info */
int     umbRegions = 0; /* How many UMB regions are there? */

struct UMBREGION {
  WORD start;      /* start of the region */
  WORD end;        /* end of the region */
  WORD minSize;    /* minimum free size, given by the L switch */
  int  access;     /* does the program have access to this region? */
} *umbRegion;


/* functions... */
int     loadhigh(char *first, char *rest);
int     loadfix(char *first, char *rest);
int     findUMBRegions(void);
int     parseArgs(char *cmdline);
void    lh_error(int errcode);
int     lh_lf(char *c);
int     loadhigh_prepare(void);
int     loadfix_prepare(void);
int     initialise(void);
void    cleanup(void);

enum error_codes {
  err_help = -1, OK, 
  
  /* These error codes are more or less DOS-compatible */
  err_file_not_found = 2, err_mcb_chain = 7,
  err_out_of_memory = 8, err_invalid_parms = 87
};

/* error message strings */
#define REGION_WARNING  "LOADHIGH: Illegal memory region %d - ignored\n"
#define FILENOTFOUND    "file not found"
#define OUTOFMEMORY     "out of memory"
#define BADUSAGE        "invalid command line"
#define BADMCBCHAIN     "MCB chain corrupt, or MS-DOS incompatible system"

/* usage strings */
char    loadhigh_usage[] =
  "LOADHIGH loads a program into the upper memory.\n\n"
  "Usage: LOADHIGH [options] filename [arguments to <filename>]\n\n"
  " /L:m[,n][;m[,n]]...  Specify which UMB regions the program can use\n"
  " /S                   Shrink the regions to minimal size"
;

char    loadfix_usage[] =
  "LOADFIX loads a program above the first 64 kb.\n\n"
  "Usage: LOADFIX filename [arguments to <filename>]"
;