4 files changed, 189 insertions(+), 5 deletions(-)

A pc/mem.h
M pc/mmu.c
A pc/trap.c
M port/devroot.c

@@ 0,0 1,99 @@
+#define SELGDT	(0<<3)	/* selector is in gdt */
+#define	SELLDT	(1<<3)	/* selector is in ldt */
+
+#define SELECTOR(i, t, p)	(((i)<<4) | (t) | (p))
+
+/*
+ *  segment descriptor/gate
+ */
+typedef struct Segdesc	Segdesc;
+struct Segdesc
+{
+	ulong	d0;
+	ulong	d1;
+};
+#define SEGDATA	(0x10<<8)	/* data/stack segment */
+#define SEGEXEC	(0x18<<8)	/* executable segment */
+#define SEGCG	(0x0C<<8)	/* call gate */
+#define	SEGIG	(0x0E<<8)	/* interrupt gate */
+#define SEGTG	(0x0F<<8)	/* task gate */
+
+#define SEGP	(1<<15)		/* segment present */
+#define SEGPL(x) ((x)<<13)	/* priority level */
+#define SEGB	(1<<22)		/* granularity 1==4k (for expand-down) */
+#define SEGG	(1<<23)		/* granularity 1==4k (for other) */
+#define SEGE	(1<<10)		/* expand down */
+#define SEGW	(1<<9)		/* writable (for data/stack) */
+#define	SEGR	(1<<9)		/* readable (for code) */
+#define SEGD	(1<<22)		/* default 1==32bit (for code) */
+
+/*
+ *  gate initializers
+ */
+#define TRAPGATE(s,o,p)	{ (o)&0xFFFF0000|SEGP|SEGPL(p)|SEGTG, (o)&0xFFFF|((s)<<16) }
+#define INTRGATE(s,o,p)	{ (o)&0xFFFF0000|SEGP|SEGPL(p)|SEGIG, (o)&0xFFFF|((s)<<16) }
+#define CALLGATE(s,o,p)	{ (o)&0xFFFF0000|SEGP|SEGPL(p)|SEGCG, (o)&0xFFFF|((s)<<16) }
+
+/*
+ *  segment descriptor initializers
+ */
+#define	DATASEG(p) 	{ SEGG|(0xF<<16)|SEGP|SEGPL(p)|SEGDATA|SEGW, 0xFFFF }
+#define	EXECSEG(p) 	{ SEGG|SEGD|(0xF<<16)|SEGP|SEGPL(p)|SEGEXEC|SEGR, 0xFFFF }
+
+/*
+ *  known segments (in GDT) and their selectors
+ */
+enum
+{
+	NULLSEG=0,	/* null segment */
+	KESEG=	1,	/* kernel executable */	
+	KDSEG=	2,	/* kernel data/stack */
+	UESEG=	3,	/* user executable */
+	UDSEG=	4,	/* user data/stack */
+	SYSGATE=5,	/* system call gate */
+};
+#define NULLSEL	SELECTOR(NULLSEG, SELGDT, 0)
+#define KESEL	SELECTOR(KESEG, SELGDT, 0)
+#define KDSEL	SELECTOR(KDSEG, SELGDT, 0)
+#define KSSEL	SELECTOR(KDSEG, SELGDT, 0)
+#define UESEL	SELECTOR(UESEG, SELGDT, 3)
+#define UDSEL	SELECTOR(UDSEG, SELGDT, 3)
+#define USSEL	SELECTOR(UDSEG, SELGDT, 3)
+
+/*
+ *  task state segment.  Plan 9 ignores all the task switching goo and just
+ *  uses the tss for esp0 and ss0 on gate's into the kernel, interrupts,
+ *  and exceptions.  The rest is completely ignored.
+ *
+ *  This means that we only need one tss in the whole system.
+ */
+typedef struct Tss	Tss;
+struct Tss
+{
+	ulong	backlink;	/* unused */
+	ulong	esp0;		/* pl0 stack pointer */
+	ulong	ss0;		/* pl0 stack selector */
+	ulong	esp1;		/* pl1 stack pointer */
+	ulong	ss1;		/* pl1 stack selector */
+	ulong	esp2;		/* pl2 stack pointer */
+	ulong	ss2;		/* pl2 stack selector */
+	ulong	cr3;		/* page table descriptor */
+	ulong	eip;		/* instruction pointer */
+	ulong	eflags;		/* processor flags */
+	ulong	eax;		/* general (hah?) registers */
+	ulong 	ecx;
+	ulong	edx;
+	ulong	ebx;
+	ulong	esp;
+	ulong	ebp;
+	ulong	esi;
+	ulong	edi;
+	ulong	es;		/* segment selectors */
+	ulong	cs;
+	ulong	ss;
+	ulong	ds;
+	ulong	fs;
+	ulong	gs;
+	ulong	ldt;		/* local descriptor table */
+	ulong	iomap;		/* io map base */
+};

@@ 5,9 5,16 @@
 #include	"fns.h"
 #include	"io.h"
 
-
-
-void
-mapstack(Proc *p)
+/*
+ *  global descriptor table describing all segments
+ */
+Segdesc gdt[1024] =
 {
-}
+[NULLSEG]	{ 0, 0},		/* null descriptor */
+[KESEG]		EXECSEG(0),		/* kernel code */
+[KDSEG]		DATASEG(0),		/* kernel data/stack */
+[UESEG]		EXECSEG(3),		/* user code */
+[UDSEG]		DATASEG(3),		/* user data/stack */
+[SYSGATE]	CALLGATE(KESEG, syscall, 3),	/* call gate for system calls */
+		{ 0, 0},		/* the rest */
+};

@@ 0,0 1,65 @@
+#include	"u.h"
+#include	"lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+#include	"io.h"
+
+void	ediv(void);
+void	edebug(void);
+void	enmi(void);
+void	ebp(void);
+void	eover(void);
+void	ebound(void);
+void	ebadop(void);
+void	enoco(void);
+void	edfault(void);
+void	enoway(void);
+void	etss(void);
+void	enoseg(void);
+void	estack(void);
+void	eprot(void);
+void	efault(void);
+
+/*
+ *  exception types
+ */
+enum {
+	Ediv=	0,	/* divide error */
+	Edebug=	1,	/* debug exceptions */
+	Enmi=	2,	/* non-maskable interrupt */
+	Ebp=	3,	/* INT 3 */
+	Eover=	4,	/* overflow */
+	Ebound=	5,	/* bounds check */
+	Ebadop=	6,	/* invalid opcode */
+	Enoco=	7,	/* coprocessor not available */
+	Edfault=8,	/* double fault */
+	Etss=	10,	/* invalid tss */
+	Enoseg=	11,	/* segment not present */
+	Estack=	12,	/* stack exception */
+	Eprot=	13,	/* general protection */
+	Efault=	14,	/* page fault */
+	Eco=	16,	/* coprocessor error */
+};
+
+/*
+ *  exception/trap gates
+ */
+Segdesc ilt[256] =
+{
+[Ediv]		TRAPGATE(KESEL, ediv, 3),
+[Edebug]	TRAPGATE(KESEL, edebug, 3),
+[Enmi]		INTRGATE(KESEL, enmi, 3),
+[Ebp]		TRAPGATE(KESEL, ebp, 3),
+[Eover]		TRAPGATE(KESEL, eover, 3),
+[Ebound]	TRAPGATE(KESEL, ebound, 3),
+[Ebadop]	TRAPGATE(KESEL, ebadop, 3),
+[Enoco]		TRAPGATE(KESEL, enoco, 3),
+[Edfault]	TRAPGATE(KESEL, edfault, 3),
+[Etss]		TRAPGATE(KESEL, etss, 3),
+[Enoseg]	TRAPGATE(KESEL, enoseg, 3),
+[Estack]	TRAPGATE(KESEL, estack, 3),
+[Eprot]		TRAPGATE(KESEL, eprot, 3),
+[Efault]	TRAPGATE(KESEL, efault, 3),
+[Eco]		TRAPGATE(KESEL, eco, 3),
+};

@@ 11,6 11,7 @@ enum{
 	Qbin,
 	Qboot,
 	Qcfs,
+	Qcryptfs,
 	Qdev,
 	Qenv,
 	Qproc,


@@ 19,6 20,9 @@ enum{
 extern long	cfslen;
 extern ulong	cfscode[];
 
+extern long	cryptfslen;
+extern ulong	cryptfscode[];
+
 
 Dirtab rootdir[]={
 	"bin",		{Qbin|CHDIR},	0,			0700,


@@ 26,6 30,7 @@ Dirtab rootdir[]={
 	"dev",		{Qdev|CHDIR},	0,			0700,
 	"env",		{Qenv|CHDIR},	0,			0700,
 	"proc",		{Qproc|CHDIR},	0,			0700,
+	"cryptfs",	{Qcryptfs},	0,			0700,
 	"cfs",		{Qcfs},		0,			0700,
 };
 


@@ 113,6 118,14 @@ rootread(Chan *c, void *buf, long n, ulong offset)
 		memmove(buf, ((char*)cfscode)+offset, n);
 		return n;
 
+	case Qcryptfs:		/* cryptfs */
+		if(offset >= cryptfslen)
+			return 0;
+		if(offset+n > cryptfslen)
+			n = cryptfslen - offset;
+		memmove(buf, ((char*)cryptfscode)+offset, n);
+		return n;
+
 	case Qdev:
 		return 0;
 	}