1 files changed, 150 insertions, 0 deletions
diff --git a/os/port/devboot.c b/os/port/devboot.c
new file mode 100644
index 00000000..66babe38
--- /dev/null
+++ b/os/port/devboot.c
@@ -0,0 +1,150 @@
+#include	"u.h"
+#include	"../port/lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+#include	"../port/error.h"
+
+enum{
+	Qdir,
+	Qboot,
+	Qmem,
+	Qkexec,
+
+	Maxkexec = 1536*1024,
+};
+
+static 
+Dirtab bootdir[]={
+	".",			{Qdir, 0, QTDIR},	0,	0555,
+	"boot",		{Qboot},	0,	0220,
+	"mem",		{Qmem},		0,	0660,
+	"kexec",		{Qkexec},		0,	0220,
+};
+
+static Chan*
+bootattach(char *spec)
+{
+	return devattach('B', spec);
+}
+
+static Walkqid*
+bootwalk(Chan *c, Chan *nc, char **name, int nname)
+{
+	return devwalk(c, nc, name, nname, bootdir, nelem(bootdir), devgen);
+}
+
+static int
+bootstat(Chan *c, uchar *dp, int n)
+{
+	return devstat(c, dp, n, bootdir, nelem(bootdir), devgen);
+}
+
+static Chan*
+bootopen(Chan *c, int omode)
+{
+	if (c->qid.path == Qkexec) {
+		c->aux = malloc(Maxkexec);
+		print("kexec buffer: %lux\n", c->aux);
+	}
+	return devopen(c, omode, bootdir, nelem(bootdir), devgen);
+}
+
+static void	 
+bootclose(Chan *c)
+{
+	if(c->qid.path == Qkexec && c->aux != nil){
+		print("exec new kernel @%lux\n", (ulong)c->aux);
+		splhi();
+		segflush(c->aux, 64*1024);
+		gotopc((ulong)c->aux);
+	}
+}
+
+static long	 
+bootread(Chan *c, void *buf, long n, vlong offset)
+{
+	switch((ulong)c->qid.path){
+
+	case Qdir:
+		return devdirread(c, buf, n, bootdir, nelem(bootdir), devgen);
+
+	case Qmem:
+		/* kernel memory */
+		if(offset>=KZERO && offset<KZERO+conf.npage*BY2PG){
+			if(offset+n > KZERO+conf.npage*BY2PG)
+				n = KZERO+conf.npage*BY2PG - offset;
+			memmove(buf, (char*)offset, n);
+			return n;
+		}
+		error(Ebadarg);
+	}
+
+	error(Egreg);
+	return 0;	/* not reached */
+}
+
+static long	 
+bootwrite(Chan *c, void *buf, long n, vlong offset)
+{
+	ulong pc;
+	uchar *p;
+
+	switch((ulong)c->qid.path){
+	case Qmem:
+		/* kernel memory */
+		if(offset>=KZERO && offset<KZERO+conf.npage*BY2PG){
+			if(offset+n > KZERO+conf.npage*BY2PG)
+				n = KZERO+conf.npage*BY2PG - offset;
+			memmove((char*)offset, buf, n);
+			segflush((void*)offset, n);
+			return n;
+		}
+		error(Ebadarg);
+
+	case Qboot:
+		p = (uchar*)buf;
+		pc = (((((p[0]<<8)|p[1])<<8)|p[2])<<8)|p[3];
+		if(pc < KZERO || pc >= KZERO+conf.npage*BY2PG)
+			error(Ebadarg);
+		splhi();
+		segflush((void*)pc, 64*1024);
+		gotopc(pc);
+
+	case Qkexec:
+		print(".");
+		if(c->aux != nil && offset <= Maxkexec){
+			if(offset+n > Maxkexec)
+				n = Maxkexec - offset;
+			memmove((char*)c->aux+offset, buf, n);
+			segflush((char*)c->aux+offset, n);
+			return n;
+		}
+		free(c->aux);
+		c->aux = nil;
+		error(Ebadarg);
+	}
+	error(Ebadarg);
+	return 0;	/* not reached */
+}
+
+Dev bootdevtab = {
+	'B',
+	"boot",
+
+	devreset,
+	devinit,
+	devshutdown,
+	bootattach,
+	bootwalk,
+	bootstat,
+	bootopen,
+	devcreate,
+	bootclose,
+	bootread,
+	devbread,
+	bootwrite,
+	devbwrite,
+	devremove,
+	devwstat,
+};