diff options
Diffstat (limited to 'doselks/doselks.c')
| -rw-r--r-- | doselks/doselks.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/doselks/doselks.c b/doselks/doselks.c new file mode 100644 index 0000000..3056e19 --- /dev/null +++ b/doselks/doselks.c @@ -0,0 +1,302 @@ +#include <stdio.h> +#include "doselks.h" + +#define DEBUGGER + +void build_stack(/* char ** argv, char ** envp */); + +long elks_int_orig; +union REGS regs; +int process_running; +int exit_code = 255; + +main(argc, argv, envp) +int argc; +char ** argv; +char ** envp; +{ + int rv; + + current_ds = __get_ds(); + if( argc <= 1 ) + { + printf("Usage: %s <8086_exe> [args]\n", argv[0]); + exit(exit_code); + } + + proc = calloc(sizeof(struct process), 1); + if( proc == 0 ) + printf("Unable to allocate memory for executable\n"); + else if( (rv = loadexe(argv[1])) >= 0 ) + { + proc->pid = 1; + proc->ppid = 1; + proc->pgrp = 1; + proc->umask = 022; + proc->next = proc; + + build_stack(argv+1, envp); + + elks_int_orig = __getvect(ELKSINT); + __setvect(ELKSINT, (long)elks_int); + +#ifndef MAKEME + run_executable(); +#else + dump_core(); +#endif + + __setvect(ELKSINT, elks_int_orig); + } + else + { + if( rv == -ENOMEM ) + printf("Unable to allocate memory for executable\n"); + else + printf("Cannot execute %s\n", argv[1]); + } + return(exit_code); +} + +int loadexe(fname) +char * fname; +{ + char bbuf[1024]; + long size; + unsigned int tsize, dsize; + struct elks_exec_hdr mh; + int i; + int fd = -1; + int err = ENOEXEC; + + proc->text_seg = 0; + proc->data_seg = 0; + + if( ( fd = open(fname, O_RDONLY|O_BINARY) ) < 0 ) + goto no_exec; + + /* Load the elks binary image and set it up in a suitable + * segment. Load CS and DS/SS according to image type. + */ + + if( read(fd, &mh,sizeof(mh))!=sizeof(mh) + || mh.hlen!=EXEC_HEADER_SIZE + || (mh.type!=ELKS_COMBID&&mh.type!=ELKS_SPLITID) + ) + goto no_exec; + + if(mh.type==ELKS_COMBID) + { + tsize = 0; + dsize = ((mh.tseg+mh.chmem + 0xF)>>4); + } + else + { + tsize = ((mh.tseg+0xF) >> 4); + dsize = ((mh.chmem+0xF) >> 4); + } + if(tsize) + { + if( (proc->text_seg = seg_allocate(tsize)) == 0) + goto no_mem; + + proc->cs = proc->text_seg->seg; + } + + if( (proc->data_seg = seg_allocate(dsize)) == 0 ) + goto no_mem; + + proc->ds = proc->data_seg->seg; + if(proc->text_seg == 0) proc->cs = proc->ds; + +#ifdef DEBUGGER + fprintf(stderr,"Executable - %s. tseg=0x%04lx dseg=0x%04lx bss=0x%04lx chmem=0x%04lx\n", + mh.type==ELKS_COMBID?"(impure)":"Sep I/D", + mh.tseg,mh.dseg,mh.bseg,mh.chmem); +#endif + + if(proc->text_seg) + { + for(size=0; size<mh.tseg; ) + { + i = sizeof(bbuf); if( i>mh.tseg-size ) i=mh.tseg-size; + + if(read(fd,bbuf,i)!=i) + goto no_exec; + + __movedata(current_ds, (unsigned)bbuf, proc->cs, (int)size, i); + size += i; + } + } + else + mh.dseg += mh.tseg; + + for(size=0; size<mh.dseg; ) + { + i = sizeof(bbuf); if( i>mh.dseg-size ) i=mh.dseg-size; + + if(read(fd,bbuf,i)!=i) + goto no_exec; + + __movedata(current_ds, (unsigned)bbuf, proc->ds, (int)size, i); + size += i; + } + + close(fd); + + /* Zap the bss */ + memset(bbuf, '\0', 1024); + mh.dseg += mh.bseg; + for(; size<mh.dseg; ) + { + i = sizeof(bbuf); if( i>mh.dseg-size ) i=mh.dseg-size; + + __movedata(current_ds, (unsigned)bbuf, proc->ds, (int)size, i); + size += i; + } + + /* + * Load the VM86 registers + */ + + proc->ss=proc->ds; + proc->es=0; /* This will be preserved */ + proc->sp=mh.chmem; /* Args stacked later */ + proc->pc=0; /* Run from 0 */ + + /* + * Loaded + */ + + return 0; +no_mem:; + err = ENOMEM; +no_exec:; + seg_free(proc->text_seg); + seg_free(proc->data_seg); + if( fd > 0 ) close(fd); + return -err; +} + +void +build_stack(argv, envp) +char ** argv; char ** envp; +{ + char buffer[1024]; + + char **p; + int argv_len=0, argv_count=0; + int envp_len=0, envp_count=0; + int stack_bytes; + unsigned short * pip; + char * pcp; + + /* How much space for argv */ + if(argv) for(p=argv; *p; p++) + { + argv_count++; argv_len += strlen(*p)+1; + } + + /* How much space for envp */ + if(envp) for(p=envp; *p; p++) + { + envp_count++; envp_len += strlen(*p)+1; + } + + /* tot it all up */ + stack_bytes = 2 /* argc */ + + argv_count * 2 + 2 /* argv */ + + argv_len + + envp_count * 2 + 2 /* envp */ + + envp_len; + + if( stack_bytes > sizeof(buffer)-2 ) + { + printf("Environment too large\n"); + exit(exit_code); + } + /* Allocate it */ + proc->sp -= stack_bytes; + +#ifdef DEBUGGER + printf("Argv = (%d,%d), Envp=(%d,%d), stack=%d\n", + argv_count, argv_len, envp_count, envp_len, stack_bytes); +#endif + + /* Now build the data */ + pip=(unsigned short *) buffer; + pcp=buffer+sizeof(unsigned short *)*(1+argv_count+1+envp_count+1); + + *pip++ = argv_count; + for(p=argv; *p; p++) + { + *pip++ = (pcp-buffer)+proc->sp; + strcpy(pcp, *p); + pcp += strlen(*p)+1; + } + *pip++ = 0; + + for(p=envp; *p; p++) + { + *pip++ = (pcp-buffer)+proc->sp; + strcpy(pcp, *p); + pcp += strlen(*p)+1; + } + *pip++ = 0; + __movedata(current_ds, (unsigned)buffer, + proc->ds, proc->sp, stack_bytes); +} + +/***************************************************************************/ + +dump_core() +{ + char bbuf[1024]; + int i, fd; + unsigned destseg; + printf("Not dumping core\n"); + +/* + if( ( fd = open("core", O_WRONLY|O_BINARY|O_CREAT|O_TRUNC) ) < 0 ) + { + return -1; + } + + destseg = proc->memory; + + for(i=0; i<(proc->memsize+63)/64; i++) + { + __movedata( destseg+i*64, 0, current_ds, (unsigned)bbuf, 1024); + if( write(fd, bbuf, 1024) < 0 ) + printf("FAIL 7\n"); + } + + close(fd); +*/ +} + +/***************************************************************************/ + +seg_allocate(size) +{ + struct segment *nptr = calloc(sizeof(struct segment),1); + + if( nptr == 0 ) return 0; + + nptr->ref_count = 1; + nptr->size = size; + nptr->seg = __segalloc(size); + if( nptr->seg == 0 ) { free(nptr); return 0; } + + return nptr; +} + +seg_free(ptr) +struct segment * ptr; +{ + if(ptr == 0) return; + if( --ptr->ref_count > 0 ) + return; + __segfree(ptr->seg); + free(ptr); +} |