ref: faa625a1d5ab47ac0438b2cea5b2bde1ea747b8b
dir: /sys/src/cmd/aux/txt2uimage.c/
#include <u.h> #include <libc.h> #include <flate.h> int infd, outfd; ulong dcrc; ulong *tab; uchar buf[65536]; enum { IH_TYPE_SCRIPT = 6, }; void put(uchar *p, u32int v) { *p++ = v >> 24; *p++ = v >> 16; *p++ = v >> 8; *p = v; } void usage(void) { fprint(2, "usage: %s a.out\n", argv0); exits("usage"); } void block(int n) { int rc; rc = readn(infd, buf, n); if(rc < 0) sysfatal("read: %r"); if(rc < n) sysfatal("input file truncated"); if(write(outfd, buf, n) < 0) sysfatal("write: %r"); dcrc = blockcrc(tab, dcrc, buf, n); } void copy(int n) { int i; for(i = sizeof(buf) - 1; i < n; i += sizeof(buf)) block(sizeof(buf)); i = n & sizeof(buf) - 1; if(i > 0) block(i); } void main(int argc, char **argv) { uchar header[64]; char *ofile; Dir *dir; ofile = nil; ARGBEGIN { case 'o': ofile = strdup(EARGF(usage())); break; default: usage(); } ARGEND; if(argc == 0) infd = 0; else { if(argc != 1) usage(); infd = open(argv[0], OREAD); if(infd < 0) sysfatal("infd: %r"); } dir = dirfstat(infd); if(dir == nil) sysfatal("stat: %r"); if(dir->length > 0xFFFFFFFF-8) sysfatal("file too big"); if(ofile == nil) ofile = smprint("%s.u", dir->name); outfd = create(ofile, OWRITE|OTRUNC, 0666); if(outfd < 0) sysfatal("create: %r"); tab = mkcrctab(0xEDB88320); seek(outfd, sizeof(header), 0); put(buf+0, dir->length); put(buf+4, 0); dcrc = blockcrc(tab, 0, buf, 8); if(write(outfd, buf, 8) != 8) sysfatal("write: %r"); copy(dir->length); memset(header, 0, sizeof(header)); put(&header[0], 0x27051956); /* magic */ put(&header[8], time(0)); /* time */ put(&header[12], 8+dir->length); /* image size */ put(&header[16], 0); /* load address */ put(&header[20], 0); /* entry point */ put(&header[24], dcrc); /* data crc */ header[28] = 0; header[29] = 0; header[30] = IH_TYPE_SCRIPT; header[31] = 0; /* compressed = no */ strncpy((char*)&header[32], dir->name, sizeof(header)-32); put(&header[4], blockcrc(tab, 0, header, sizeof(header))); seek(outfd, 0, 0); if(write(outfd, header, sizeof(header)) < sizeof(header)) sysfatal("write: %r"); exits(nil); }