#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"

#include "init.h"
#include "arm.h"
#include <pool.h>

#include "reboot.h"

uintptr kseg0 = KZERO;
Mach* machaddr[MAXMACH];

/*
 * Option arguments from the command line.
 * oargv[0] is the boot file.
 * Optionsinit() is called from multiboot()
 * or some other machine-dependent place
 * to set it all up.
 */
static int oargc;
static char* oargv[20];
static char oargb[128];
static int oargblen;
static char oenv[4096];

static uintptr sp;		/* XXX - must go - user stack of init proc */

int vflag;
char debug[256];

static void
optionsinit(char* s)
{
	char *o;
#ifdef USE_FLASH
	uintptr va;
	char *p;

	va = 0xf0000000;
	if(mmukmap(va, PHYSFLASH, 1*MiB) != 0){
		o = oenv;
		for(p = (char*)(va+256*KiB+4); *p != 0; p += strlen(p)+1)
			o = strecpy(o, oenv+sizeof(oenv), p)+1;
		mmukunmap(va, PHYSFLASH, 1*MiB);
	}
#else
	strcpy(oenv, "ethaddr=00:50:43:01:c4:9e");	// TODO
#endif

	o = strecpy(oargb, oargb+sizeof(oargb), s)+1;
	if(getenv("bootargs", o, o - oargb) != nil)
		*(o-1) = ' ';

	oargblen = strlen(oargb);
	oargc = tokenize(oargb, oargv, nelem(oargv)-1);
	oargv[oargc] = nil;
}

char*
getenv(char* name, char* buf, int n)
{
	char *e, *p, *q;

	p = oenv;
	while(*p != 0){
		if((e = strchr(p, '=')) == nil)
			break;
		for(q = name; p < e; p++){
			if(*p != *q)
				break;
			q++;
		}
		if(p == e && *q == 0){
			strecpy(buf, buf+n, e+1);
			return buf;
		}
		p += strlen(p)+1;
	}

	return nil;
}

#include "io.h"

typedef struct Spiregs Spiregs;
struct Spiregs {
	ulong	ictl;		/* interface ctl */
	ulong	icfg;		/* interface config */
	ulong	out;		/* data out */
	ulong	in;		/* data in */
	ulong	ic;		/* interrupt cause */
	ulong	im;		/* interrupt mask */
	ulong	_pad[2];
	ulong	dwrcfg;		/* direct write config */
	ulong	dwrhdr;		/* direct write header */
};

enum {
	/* ictl bits */
	Csnact	= 1<<0,		/* serial memory activated */

	/* icfg bits */
	Bytelen	= 1<<5,		/* 2^(this_bit) bytes per transfer */
	Dirrdcmd= 1<<10,	/* flag: fast read */
};

static void
dumpbytes(uchar *bp, long max)
{
	iprint("%#p: ", bp);
	for (; max > 0; max--)
		iprint("%02.2ux ", *bp++);
	iprint("...\n");
}

vlong	probeaddr(uintptr);

// linux sez environment is in nand, 128K at offset 0x40000
static void
spiprobe(void)
{
	Spiregs *rp = (Spiregs *)AddrSpi;

	l2cacheon();

	rp->ictl |= Csnact;
	coherence();
	rp->icfg |= Dirrdcmd | 3<<8;	/* fast reads, 4-byte addresses */
	rp->icfg &= ~Bytelen;		/* one-byte reads */
	coherence();

	print("spi flash at %#ux: memory reads enabled\n", PHYSSPIFLASH);
#ifdef AMBITIOUS
	uchar *p, *ep, *np;

	p = (uchar *)PHYSSPIFLASH;
	ep = p + FLASHSIZE - 64;
iprint("scan: ");
	for (; p < ep - 1; p++) {
iprint("%#p of %,ld bytes...", p, ep - p);
		np = memchr(p, 'e', ep - p);
		if (np == nil)
			break;
		p = np;
		if (*p == 'e' && memcmp(p, "ethaddr", 7) == 0)
			break;
	}
	dumpbytes(p, 64);
#endif
}

void	archconsole(void);

/*
 * this low-level printing stuff is ugly,
 * but there appears to be no other way to
 * print until after #t is populated.
 */

#define wave(c) { \
	coherence(); \
	while ((*(ulong *)(PHYSCONS+4*5) & (1<<5)) == 0) /* (x->lsr&LSRthre)==0? */ \
		; \
	*(ulong *)PHYSCONS = (c); \
	coherence(); \
}

/*
 * entered from l.s with mmu enabled.
 *
 * we may have to realign the data segment; apparently 5l -H0 -R4096
 * does not pad the text segment.  on the other hand, we may have been
 * loaded by another kernel.
 *
 * be careful not to touch the data segment until we know it's aligned.
 */
void
main(Mach* mach)
{
	extern char bdata[], edata[], end[], etext[];
	static ulong vfy = 0xcafebabe;

	m = mach;
	if (vfy != 0xcafebabe)
		memmove(bdata, etext, edata - bdata);
	if (vfy != 0xcafebabe) {
		wave('?');
		panic("misaligned data segment");
	}
	memset(edata, 0, end - edata);		/* zero bss */
	vfy = 0;

wave('9');
	machinit();
	archreset();
	mmuinit();

	optionsinit("/boot/boot boot");
	quotefmtinstall();
	archconsole();
wave('\n');

	confinit();
	xinit();
wave('\r');

	/*
	 * Printinit will cause the first malloc call.
	 * (printinit->qopen->malloc) unless any of the
	 * above (like clockintr) do an irqenable, which
	 * will call malloc.
	 * If the system dies here it's probably due
	 * to malloc(->xalloc) not being initialised
	 * correctly, or the data segment is misaligned
	 * (it's amazing how far you can get with
	 * things like that completely broken).
	 *
	 * (Should be) boilerplate from here on.
	 */
	trapinit();
	clockinit();

	printinit();
	/* only now can we print */
	uartkirkwoodconsole();
	archconfinit();
	cpuidprint();
	timersinit();

	procinit0();
	initseg();
	links();
	chandevreset();

	spiprobe();

	pageinit();
	swapinit();
	userinit();
	schedinit();
}

void
cpuidprint(void)
{
	char name[64];

	cputype2name(name, sizeof name);
	print("cpu%d: %lldMHz ARM %s\n", m->machno, m->cpuhz/1000000, name);
}

void
machinit(void)
{
	memset(m, 0, sizeof(Mach));
	m->machno = 0;
	machaddr[m->machno] = m;

	m->ticks = 1;
	m->perf.period = 1;

	conf.nmach = 1;

	active.machs = 1;
	active.exiting = 0;

	up = nil;
}

static void
shutdown(int ispanic)
{
	int ms, once;

	lock(&active);
	if(ispanic)
		active.ispanic = ispanic;
	else if(m->machno == 0 && (active.machs & (1<<m->machno)) == 0)
		active.ispanic = 0;
	once = active.machs & (1<<m->machno);
	active.machs &= ~(1<<m->machno);
	active.exiting = 1;
	unlock(&active);

	if(once)
		iprint("cpu%d: exiting\n", m->machno);
	spllo();
	for(ms = 5*1000; ms > 0; ms -= TK2MS(2)){
		delay(TK2MS(2));
		if(active.machs == 0 && consactive() == 0)
			break;
	}
	delay(1000);
}

/*
 *  exit kernel either on a panic or user request
 */
void
exit(int code)
{
	shutdown(code);
	splhi();
	archreboot();
}

/*
 * the new kernel is already loaded at address `code'
 * of size `size' and entry point `entry'.
 */
void
reboot(void *entry, void *code, ulong size)
{
	void (*f)(ulong, ulong, ulong);

	iprint("starting reboot...");
//	writeconf();
	shutdown(0);

	/*
	 * should be the only processor running now
	 */

	print("shutting down...\n");
	delay(200);

	splhi();

	/* turn off buffered serial console */
	serialoq = nil;

	/* shutdown devices */
	devtabshutdown();

	/* setup reboot trampoline function */
	f = (void*)REBOOTADDR;
	memmove(f, rebootcode, sizeof(rebootcode));
	coherence();
	dcflushall();
	icflushall();

	print("rebooting...");
	iprint("entry %#lux code %#lux size %ld\n",
		PADDR(entry), PADDR(code), size);
	delay(100);		/* wait for uart to quiesce */

	/* off we go - never to return */
	coherence();
	dcflushall();
	icflushall();
	(*f)(PADDR(entry), PADDR(code), size);

	iprint("loaded kernel returned!\n");
	delay(500);
	archreboot();
}

/*
 *  starting place for first process
 */
void
init0(void)
{
	char buf[2*KNAMELEN];

	assert(up != nil);
	up->nerrlab = 0;
	coherence();
	spllo();

	/*
	 * These are o.k. because rootinit is null.
	 * Then early kproc's will have a root and dot.
	 */
	up->slash = namec("#/", Atodir, 0, 0);
	pathclose(up->slash->path);
	up->slash->path = newpath("/");
	up->dot = cclone(up->slash);

	devtabinit();

	if(!waserror()){
		snprint(buf, sizeof(buf), "%s %s", "ARM", conffile);
		ksetenv("terminal", buf, 0);
		ksetenv("cputype", "arm", 0);
		if(cpuserver)
			ksetenv("service", "cpu", 0);
		else
			ksetenv("service", "terminal", 0);

		/* sheevaplug configuration */
		ksetenv("nvram", "/boot/nvram", 0);
		ksetenv("nvroff", "0", 0);
		ksetenv("nvrlen", "512", 0);
		ksetenv("nobootprompt", "tcp", 0);

		poperror();
	}
	kproc("alarm", alarmkproc, 0);

	touser(sp);
}

static void
bootargs(uintptr base)
{
	int i;
	ulong ssize;
	char **av, *p;

	/*
	 * Push the boot args onto the stack.
	 * The initial value of the user stack must be such
	 * that the total used is larger than the maximum size
	 * of the argument list checked in syscall.
	 */
	i = oargblen+1;
	p = UINT2PTR(STACKALIGN(base + PGSIZE - sizeof(up->s.args) - i));
	memmove(p, oargb, i);

	/*
	 * Now push argc and the argv pointers.
	 * This isn't strictly correct as the code jumped to by
	 * touser in init9.s calls startboot (port/initcode.c) which
	 * expects arguments
	 * 	startboot(char *argv0, char **argv)
	 * not the usual (int argc, char* argv[]), but argv0 is
	 * unused so it doesn't matter (at the moment...).
	 */
	av = (char**)(p - (oargc+2)*sizeof(char*));
	ssize = base + PGSIZE - PTR2UINT(av);
	*av++ = (char*)oargc;
	for(i = 0; i < oargc; i++)
		*av++ = (oargv[i] - oargb) + (p - base) + (USTKTOP - BY2PG);
	*av = nil;

	/*
	 * Leave space for the return PC of the
	 * caller of initcode.
	 */
	sp = USTKTOP - ssize - sizeof(void*);
}

/*
 *  create the first process
 */
void
userinit(void)
{
	Proc *p;
	Segment *s;
	KMap *k;
	Page *pg;

	/* no processes yet */
	up = nil;

	p = newproc();
	p->pgrp = newpgrp();
	p->egrp = smalloc(sizeof(Egrp));
	p->egrp->ref = 1;
	p->fgrp = dupfgrp(nil);
	p->rgrp = newrgrp();
	p->procmode = 0640;

	kstrdup(&eve, "");
	kstrdup(&p->text, "*init*");
	kstrdup(&p->user, eve);

	/*
	 * Kernel Stack
	 */
	p->sched.pc = PTR2UINT(init0);
	p->sched.sp = PTR2UINT(p->kstack+KSTACK-sizeof(up->s.args)-sizeof(uintptr));
	p->sched.sp = STACKALIGN(p->sched.sp);

	/*
	 * User Stack
	 *
	 * Technically, newpage can't be called here because it
	 * should only be called when in a user context as it may
	 * try to sleep if there are no pages available, but that
	 * shouldn't be the case here.
	 */
	s = newseg(SG_STACK, USTKTOP-USTKSIZE, USTKSIZE/BY2PG);
	p->seg[SSEG] = s;
	pg = newpage(1, 0, USTKTOP-BY2PG);
	segpage(s, pg);
	k = kmap(pg);
	bootargs(VA(k));
	kunmap(k);

	/*
	 * Text
	 */
	s = newseg(SG_TEXT, UTZERO, 1);
	s->flushme++;
	p->seg[TSEG] = s;
	pg = newpage(1, 0, UTZERO);
	memset(pg->cachectl, PG_TXTFLUSH, sizeof(pg->cachectl));
	segpage(s, pg);
	k = kmap(s->map[0]->pages[0]);
	memmove(UINT2PTR(VA(k)), initcode, sizeof initcode);
	kunmap(k);

	ready(p);
}

Conf conf;			/* XXX - must go - gag */

Confmem sheevamem[] = {
	/*
	 * Memory available to Plan 9:
	 */
	{ .base = 0x00000000, .limit = 512*1024*1024, },
};

void
confinit(void)
{
	int i;
	ulong kpages;
	uintptr pa;

	/*
	 * Copy the physical memory configuration to Conf.mem.
	 * The physical memory configuration will be used later
	 * to check against what the the Pico Array wants.
	 */
	if(nelem(sheevamem) > nelem(conf.mem)){
		iprint("memory configuration botch\n");
		exit(1);
	}
	memmove(conf.mem, sheevamem, sizeof(sheevamem));

	conf.npage = 0;
	pa = PADDR(PGROUND(PTR2UINT(end)));

	/*
	 *  we assume that the kernel is at the beginning of one of the
	 *  contiguous chunks of memory and fits therein.
	 */
	for(i=0; i<nelem(conf.mem); i++){
		/* take kernel out of allocatable space */
		if(pa > conf.mem[i].base && pa < conf.mem[i].limit)
			conf.mem[i].base = pa;

		conf.mem[i].npage = (conf.mem[i].limit - conf.mem[i].base)/BY2PG;
		conf.npage += conf.mem[i].npage;
	}

	conf.upages = (conf.npage*90)/100;
	conf.ialloc = ((conf.npage-conf.upages)/2)*BY2PG;

	/* only one processor */
	conf.nmach = 1;

	/* set up other configuration parameters */
	conf.nproc = 100 + ((conf.npage*BY2PG)/MB)*5;
	if(cpuserver)
		conf.nproc *= 3;
	if(conf.nproc > 2000)
		conf.nproc = 2000;
	conf.nswap = conf.npage*3;
	conf.nswppo = 4096;
	conf.nimage = 200;

	conf.copymode = 0;		/* copy on write */

	/*
	 * Guess how much is taken by the large permanent
	 * datastructures. Mntcache and Mntrpc are not accounted for
	 * (probably ~300KB).
	 */
	kpages = conf.npage - conf.upages;
	kpages *= BY2PG;
	kpages -= conf.upages*sizeof(Page)
		+ conf.nproc*sizeof(Proc)
		+ conf.nimage*sizeof(Image)
		+ conf.nswap
		+ conf.nswppo*sizeof(Page);
	mainmem->maxsize = kpages;
	if(!cpuserver)
		/*
		 * give terminals lots of image memory, too; the dynamic
		 * allocation will balance the load properly, hopefully.
		 * be careful with 32-bit overflow.
		 */
		imagmem->maxsize = kpages;
}

char*
getconf(char *)
{
	return nil;
}

int
cmpswap(long *addr, long old, long new)
{
	return cas32(addr, old, new);
}