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#include	"u.h"
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#include	"../port/lib.h"
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#include	"mem.h"
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#include	"dat.h"
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#include	"fns.h"
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#include	"../port/error.h"
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#include	<a.out.h>
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#include 	"/sys/src/libmach/elf.h"
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enum {
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	Ehdr32sz	= 52,
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	Phdr32sz	= 32,
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	Shdr32sz	= 40,
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	Ehdr64sz	= 64,
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	Phdr64sz	= 56,
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	Shdr64sz	= 64,
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};
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static uchar elfident[] = {
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	'\177', 'E', 'L', 'F',
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};
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void
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readn(Chan *c, void *vp, long n)
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{
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	char *p = vp;
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	long nn;
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	while(n > 0) {
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		nn = devtab[c->type]->read(c, p, n, c->offset);
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		if(nn == 0)
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			error(Eshort);
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		c->offset += nn;
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		p += nn;
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		n -= nn;
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	}
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}
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/* assume the elf header is in the byte order of this machine */
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int
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readelfhdr(Chan *c, ulong, Execvals *evp)
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{
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	Ehdr ehdr;
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	Phdr phdrs[3];
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	c->offset = 0;			/* back up */
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	readn(c, &ehdr, sizeof ehdr);
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	if(memcmp(&ehdr.ident[MAG0], elfident, sizeof elfident) != 0 ||
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	    ehdr.ident[CLASS] != ELFCLASS32)
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		return -1;
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	/* get textsize and datasize from Phdrs */
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	readn(c, phdrs, sizeof phdrs);
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	evp->entry = ehdr.elfentry;
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	evp->textsize = phdrs[0].filesz;
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	evp->datasize = phdrs[1].filesz;
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	c->offset = ROUNDUP(Ehdr32sz + 3*Phdr32sz, 16);	/* position for text */
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	return 0;
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}
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static int
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readelf64hdr(Chan *c, ulong, Execvals *evp)
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{
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	E64hdr ehdr;
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	P64hdr phdrs[3];
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	c->offset = 0;			/* back up */
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	readn(c, &ehdr, sizeof ehdr);
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	if(memcmp(&ehdr.ident[MAG0], elfident, sizeof elfident) != 0 ||
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	    ehdr.ident[CLASS] != ELFCLASS64)
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		return -1;
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	/* get textsize and datasize from Phdrs */
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	readn(c, phdrs, sizeof phdrs);
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	evp->entry = ehdr.elfentry;
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	evp->textsize = phdrs[0].filesz;
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	evp->datasize = phdrs[1].filesz;
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	c->offset = ROUNDUP(Ehdr64sz + 3*Phdr64sz, 16);	/* position for text */
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	return 0;
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}
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static void
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setbootcmd(int argc, char *argv[])
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{
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	char *buf, *p, *ep;
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	int i;
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	buf = malloc(1024);
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	if(buf == nil)
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		error(Enomem);
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	p = buf;
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	ep = buf + 1024;
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	for(i=0; i<argc; i++)
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		p = seprint(p, ep, "%q ", argv[i]);
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	*p = 0;
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	ksetenv("bootcmd", buf, 1);
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	free(buf);
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}
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void
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rebootcmd(int argc, char *argv[])
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{
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	Chan *c;
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	Exec exec;
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	Execvals ev;
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	ulong magic, text, rtext, entry, data, size;
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	uchar *p;
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110 
	if(argc == 0)
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		exit(0);
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	c = namec(argv[0], Aopen, OEXEC, 0);
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	if(waserror()){
115 
		cclose(c);
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		nexterror();
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	}
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119 
	readn(c, &exec, sizeof(Exec));
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	magic = l2be(exec.magic);
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	/*
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	 * AOUT_MAGIC is sometimes defined like this:
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	 * #define AOUT_MAGIC	V_MAGIC || magic==M_MAGIC
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	 * so we can only use it in a fairly stylized manner.
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	 */
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	if(magic == AOUT_MAGIC) {
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		entry = l2be(exec.entry);
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		text = l2be(exec.text);
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		data = l2be(exec.data);
130 
	} else if(parseboothdr && (*parseboothdr)(c, magic, &ev) >= 0 ||
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	    readelfhdr(c, magic, &ev) >= 0 ||
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	    readelf64hdr(c, magic, &ev) >= 0){
133 
		entry = ev.entry;
134 
		text = ev.textsize;
135 
		data = ev.datasize;
136 
	} else {
137 
		error(Ebadexec);
138 
		return;				/* for the compiler */
139 
	}
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141 
	/* round text out to page boundary */
142 
	rtext = ROUNDUP(entry+text, BY2PG) - entry;
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	size = rtext + data;
144 
	p = malloc(size);
145 
	if(p == nil)
146 
		error(Enomem);
147 
 
148 
	if(waserror()){
149 
		free(p);
150 
		nexterror();
151 
	}
152 
 
153 
	memset(p, 0, size);
154 
	readn(c, p, text);
155 
	readn(c, p + rtext, data);
156 
 
157 
	ksetenv("bootfile", argv[0], 1);
158 
	setbootcmd(argc-1, argv+1);
159 
 
160 
	reboot((void*)entry, p, size);
161 
 
162 
	panic("return from reboot!");
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}