source: buchla-68k/rom/booter.c@ 4b63bf3

/*
   ============================================================================
        booter.c -- load an absolute format Alcyon object file
        Version 18 -- 1987-11-06 -- D.N. Lynx Crowe
   ============================================================================
*/

#define PRINTIT 1       /* define non-zero to get printf output from booter */

#include "rom.h"

static FILE     *B_file;                /* boot file pointer */

struct  EXFILE B_fhdr;  /* executable file header */

int32_t B_txt_o,        /* test origin from file header */
        B_dat_o,        /* data origin from file header */
        B_bss_o,        /* bss origin from file header */
        B_txt_l,        /* text length from file header */
        B_dat_l,        /* data length from file header */
        B_bss_l,        /* bss length from file header */
        B_lod_l,        /* total data length loaded */
        B_end,          /* end address */
        B_chk;          /* checksum */

int32_t B_buf_a;        /* boot load address */

int16_t B_log_s;        /* boot log switch */
int16_t B_dbg_s;        /* boot debug switch */

/*
   ============================================================================
        booter(fn, textadr) -- load file named by string 'fn' at 'textadr'.
        If 'textadr' is 0, the text origin from the file will be used.
        Returns 0 if load was OK, non-zero error code otherwise.
   ============================================================================
*/

int16_t booter(int8_t *fn, int32_t textadr)
{
        register int32_t i, bgnbss, endbss;
        register int8_t *cp;
#if     PRINTIT
        register struct fcb *fcp;
#endif

        /* initialize the origins and lengths to 0 */

        B_txt_o = 0L;
        B_dat_o = 0L;
        B_bss_o = 0L;
        B_txt_l = 0L;
        B_dat_l = 0L;
        B_bss_l = 0L;
        B_lod_l = 0L;

        /* open the file */

        if (NULL EQ (B_file = fopenb(fn, "r"))) {

#if     PRINTIT
                if (B_log_s)
                        printf("booter:  Unable to open \042%s\042\n", fn);
#endif
                return(1);
        }

#if     PRINTIT
        if (B_dbg_s) {          /* if we're debugging, print the FCB stuff */

                fcp = (struct fcb *)(chantab[B_file->_unit].c_arg);

                SnapFCB(fcp);
                ClusMap(fcp);
                waitcr2();
        }
#endif

        /* read in the file header */

        if (1 NE fread(&B_fhdr, sizeof B_fhdr, 1, B_file)) {

#if     PRINTIT
                if (B_log_s)
                        printf("booter:  Unable to read header for \042%s\042\n", fn);
#endif
                fclose(B_file);
                return(2);
        }

        /* check the magic */

        if ((B_fhdr.F_Magic NE F_R_C) AND (B_fhdr.F_Magic NE F_R_D)) {

#if     PRINTIT
                if (B_log_s)
                        printf("booter:  Bad magic [0x%04x] in file \042%s\042",
                                B_fhdr.F_Magic, fn);
#endif
                fclose(B_file);
                return(3);
        }

        /* if it's a discontinuous file, read the origins */

        if (B_fhdr.F_Magic EQ F_R_D) {

                B_dat_o = getl(B_file);
                B_bss_o  = getl(B_file);
        }

        B_txt_o = B_fhdr.F_Res2;

        B_buf_a = textadr ? textadr : B_txt_o;
        B_lod_l = B_fhdr.F_Text + B_fhdr.F_Data;

        if (0 NE flread((void *)B_buf_a, B_lod_l, B_file)) {
        
#if     PRINTIT
                if (B_log_s)
                        printf("booter:  Unable to read \042%s\042\n", fn);
#endif
                fclose(B_file);
                return(4);
        }

        B_end = B_buf_a + B_lod_l - 1L;

        B_txt_l = B_fhdr.F_Text;
        B_dat_l = B_fhdr.F_Data;
        B_bss_l = B_fhdr.F_BSS;

        cp    = (int8_t *)B_buf_a;      /* calculate checksum */
        B_chk = 0L;

        for (i = 0; i < B_lod_l; i++)
                B_chk += *cp++ & 0x000000FFL;

        if (B_bss_o)
                bgnbss = B_bss_o;
        else
                bgnbss = B_end + 1L;

        endbss = bgnbss + B_bss_l - 1L;

#if     PRINTIT
        if (B_log_s) {

                printf("File \042%s\042 loaded from $%08lX to $%08lX\r\n",
                        fn, B_buf_a, B_end);
                printf("   BSS $%08lX to $%08lX\r\n", bgnbss, endbss);
                printf("Checksum   = $%08lX, Load length = %ld ($%08lX)\r\n",
                        B_chk, B_lod_l, B_lod_l);
                printf("   B_txt_o = $%08lX, B_dat_o = $%08lX, B_bss_o = $%08lX\r\n",
                        B_txt_o, B_dat_o, B_bss_o);
                printf("   B_txt_l = $%08lX, B_dat_l = $%08lX, B_bss_l = $%08lX\r\n",
                        B_txt_l, B_dat_l, B_bss_l);
        }
#endif

        fclose(B_file);
        return(0);
}