From: John Hodge <tpg@mutabah.net>
Date: Sat, 15 Oct 2011 00:19:45 +0000 (+0800)
Subject: Kernel/armv7 - Bugfixing, can get to user relocation now
X-Git-Tag: rel0.13~68
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=f4ea8dd4c261e7a3a10d768c01cd3a121b42a045;p=tpg%2Facess2.git

Kernel/armv7 - Bugfixing, can get to user relocation now
---

diff --git a/Kernel/arch/armv7/include/mm_virt.h b/Kernel/arch/armv7/include/mm_virt.h
index dc1ed3cf..c1f10deb 100644
--- a/Kernel/arch/armv7/include/mm_virt.h
+++ b/Kernel/arch/armv7/include/mm_virt.h
@@ -7,13 +7,17 @@
 
 #include "options.h"
 
+#define USER_STACK_COMM    0x04000	// Pages to allocate up front
+#define USER_STACK_SIZE	   0x10000	// Stack space
+#define USER_STACK_TOP	0x78000000
+
 #define MM_USER_MIN	0x00001000
 #define USER_LIB_MAX	0x70000000
-#define MM_KSTACK_BASE	0x70000000
-#define MM_KSTACK_END	0x7F000000
 #define MM_PPD_HANDLES	0x7F800000
 #define MM_TABLE1USER	0x7FC00000	// 2 GiB - 4 MiB
 #define MM_TABLE0USER	0x7FE00000	// 2 GiB - 2 MiB
+#define MM_KSTACK_BASE	0x7FE00000
+#define MM_KSTACK_END	0x80000000
 
 // Page Blocks are 12-bits wide (12 address bits used)
 // Hence, the table is 16KiB large (and must be so aligned)
diff --git a/Kernel/arch/armv7/include/proc.h b/Kernel/arch/armv7/include/proc.h
index 4d48f544..d6ef3d55 100644
--- a/Kernel/arch/armv7/include/proc.h
+++ b/Kernel/arch/armv7/include/proc.h
@@ -37,10 +37,6 @@ typedef struct {
 	Uint32	Arg4;
 	Uint32	Arg5;
 	Uint32	Arg6;	// R6
-	Uint32	Unused[13-6];
-	Uint32	StackPointer;	// R13
-	Uint32	_lr;
-	Uint32	_ip;
 } tSyscallRegs;
 
 // === MACROS ===
diff --git a/Kernel/arch/armv7/mm_virt.c b/Kernel/arch/armv7/mm_virt.c
index 1f10cd5c..2555b8a1 100644
--- a/Kernel/arch/armv7/mm_virt.c
+++ b/Kernel/arch/armv7/mm_virt.c
@@ -9,10 +9,11 @@
 #include <mm_virt.h>
 #include <hal_proc.h>
 
-#define AP_KRW_ONLY	0x1
-#define AP_KRO_ONLY	0x5
-#define AP_RW_BOTH	0x3
-#define AP_RO_BOTH	0x6
+#define AP_KRW_ONLY	1	// Kernel page
+#define AP_KRO_ONLY	5	// Kernel RO page
+#define AP_RW_BOTH	3	// Standard RW
+#define AP_RO_BOTH	6	// COW Page
+#define AP_RO_USER	2	// User RO Page
 #define PADDR_MASK_LVL1	0xFFFFFC00
 
 // === IMPORTS ===
@@ -41,6 +42,8 @@ void	MM_int_GetTables(tVAddr VAddr, Uint32 **Table0, Uint32 **Table1);
  int	MM_int_AllocateCoarse(tVAddr VAddr, int Domain);
  int	MM_int_SetPageInfo(tVAddr VAddr, tMM_PageInfo *pi);
  int	MM_int_GetPageInfo(tVAddr VAddr, tMM_PageInfo *pi);
+tVAddr	MM_NewUserStack(void);
+tPAddr	MM_AllocateZero(tVAddr VAddr);
 tPAddr	MM_AllocateRootTable(void);
 void	MM_int_CloneTable(Uint32 *DestEnt, int Table);
 tPAddr	MM_Clone(void);
@@ -49,6 +52,7 @@ void	MM_int_DumpTableEnt(tVAddr Start, size_t Len, tMM_PageInfo *Info);
 //void	MM_DumpTables(tVAddr Start, tVAddr End);
 
 // === GLOBALS ===
+tPAddr	giMM_ZeroPage;
 
 // === CODE ===
 int MM_InitialiseVirtual(void)
@@ -325,6 +329,8 @@ Uint MM_GetFlags(tVAddr VAddr)
 	
 	switch(pi.AP)
 	{
+	case 0:
+		break;
 	case AP_KRW_ONLY:
 		ret |= MM_PFLAG_KERNEL;
 		break;
@@ -334,6 +340,9 @@ Uint MM_GetFlags(tVAddr VAddr)
 	case AP_RW_BOTH:
 		break;
 	case AP_RO_BOTH:
+		ret |= MM_PFLAG_COW;
+		break;
+	case AP_RO_USER:
 		ret |= MM_PFLAG_RO;
 		break;
 	}
@@ -345,8 +354,37 @@ Uint MM_GetFlags(tVAddr VAddr)
 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 {
 	tMM_PageInfo	pi;
+	Uint	curFlags;
+	
 	if( MM_int_GetPageInfo(VAddr, &pi) )
-		return;
+		return ;
+	
+	curFlags = MM_GetPhysAddr(VAddr);
+	if( (curFlags & Mask) == Flags )
+		return ;
+	curFlags &= ~Mask;
+	curFlags |= Flags;
+
+	if( curFlags & MM_PFLAG_COW )
+		pi.AP = AP_RO_BOTH;
+	else
+	{
+		switch(curFlags & (MM_PFLAG_KERNEL|MM_PFLAG_RO) )
+		{
+		case 0:
+			pi.AP = AP_RW_BOTH;	break;
+		case MM_PFLAG_KERNEL:
+			pi.AP = AP_KRW_ONLY;	break;
+		case MM_PFLAG_RO:
+			pi.AP = AP_RO_USER;	break;
+		case MM_PFLAG_KERNEL|MM_PFLAG_RO:
+			pi.AP = AP_KRO_ONLY;	break;
+		}
+	}
+	
+	pi.bExecutable = !!(curFlags & MM_PFLAG_EXEC);
+
+	MM_int_SetPageInfo(VAddr, &pi);
 }
 
 int MM_Map(tVAddr VAddr, tPAddr PAddr)
@@ -356,7 +394,10 @@ int MM_Map(tVAddr VAddr, tPAddr PAddr)
 	
 	pi.PhysAddr = PAddr;
 	pi.Size = 12;
-	pi.AP = AP_KRW_ONLY;	// Kernel Read/Write
+	if(VAddr < USER_STACK_TOP)
+		pi.AP = AP_RW_BOTH;
+	else
+		pi.AP = AP_KRW_ONLY;	// Kernel Read/Write
 	pi.bExecutable = 1;
 	if( MM_int_SetPageInfo(VAddr, &pi) ) {
 		MM_DerefPhys(pi.PhysAddr);
@@ -374,7 +415,10 @@ tPAddr MM_Allocate(tVAddr VAddr)
 	pi.PhysAddr = MM_AllocPhys();
 	if( pi.PhysAddr == 0 )	LEAVE_RET('i', 0);
 	pi.Size = 12;
-	pi.AP = AP_KRW_ONLY;	// Kernel Read/Write
+	if(VAddr < USER_STACK_TOP)
+		pi.AP = AP_RW_BOTH;
+	else
+		pi.AP = AP_KRW_ONLY;
 	pi.bExecutable = 1;
 	if( MM_int_SetPageInfo(VAddr, &pi) ) {
 		MM_DerefPhys(pi.PhysAddr);
@@ -385,6 +429,21 @@ tPAddr MM_Allocate(tVAddr VAddr)
 	return pi.PhysAddr;
 }
 
+tPAddr MM_AllocateZero(tVAddr VAddr)
+{
+	if( !giMM_ZeroPage ) {
+		giMM_ZeroPage = MM_Allocate(VAddr);
+		MM_RefPhys(giMM_ZeroPage);
+		memset((void*)VAddr, 0, PAGE_SIZE);
+	}
+	else {
+		MM_RefPhys(giMM_ZeroPage);
+		MM_Map(VAddr, giMM_ZeroPage);
+	}
+	MM_SetFlags(VAddr, MM_PFLAG_COW, MM_PFLAG_COW);
+	return giMM_ZeroPage;
+}
+
 void MM_Deallocate(tVAddr VAddr)
 {
 	tMM_PageInfo	pi;
@@ -687,13 +746,59 @@ tVAddr MM_NewKStack(int bShared)
 	return addr + ofs;
 }
 
+tVAddr MM_NewUserStack(void)
+{
+	tVAddr	addr, ofs;
+
+	addr = USER_STACK_TOP - USER_STACK_SIZE;
+	if( MM_GetPhysAddr(addr + PAGE_SIZE) ) {
+		Log_Error("MMVirt", "Unable to create initial user stack, addr %p taken",
+			addr + PAGE_SIZE
+			);
+		return 0;
+	}
+
+	// 1 guard page
+	for( ofs = PAGE_SIZE; ofs < USER_STACK_SIZE; ofs += PAGE_SIZE )
+	{
+		tPAddr	rv;
+		if(ofs >= USER_STACK_SIZE - USER_STACK_COMM)
+			rv = MM_Allocate(addr + ofs);
+		else
+			rv = MM_AllocateZero(addr + ofs);
+		if(rv == 0)
+		{
+			while(ofs)
+			{
+				ofs -= PAGE_SIZE;
+				MM_Deallocate(addr + ofs);
+			}
+			Log_Warning("MMVirt", "MM_NewUserStack: Unable to allocate");
+			return 0;
+		}
+		MM_SetFlags(addr+ofs, 0, MM_PFLAG_KERNEL);
+	}
+	Log("Return %p", addr + ofs);
+	MM_DumpTables(0, 0x80000000);
+	return addr + ofs;
+}
+
 void MM_int_DumpTableEnt(tVAddr Start, size_t Len, tMM_PageInfo *Info)
 {
-	Log("%p => %8x - 0x%7x %i %x",
-		Start, Info->PhysAddr-Len, Len,
-		Info->Domain,
-		Info->AP
-		);
+	if( giMM_ZeroPage && Info->PhysAddr == giMM_ZeroPage )
+	{
+		Log("%p => %8s - 0x%7x %i %x",
+			Start, "ZERO", Len,
+			Info->Domain, Info->AP
+			);
+	}
+	else
+	{
+		Log("%p => %8x - 0x%7x %i %x",
+			Start, Info->PhysAddr-Len, Len,
+			Info->Domain, Info->AP
+			);
+	}
 }
 
 void MM_DumpTables(tVAddr Start, tVAddr End)
@@ -724,7 +829,9 @@ void MM_DumpTables(tVAddr Start, tVAddr End)
 		}
 		
 		pi_old = pi;
-		pi_old.PhysAddr += 1 << pi_old.Size;
+		// Handle the zero page
+		if( !giMM_ZeroPage || pi_old.Size != 12 || pi_old.PhysAddr != giMM_ZeroPage )
+			pi_old.PhysAddr += 1 << pi_old.Size;
 		addr += 1 << pi_old.Size;
 		inRange = (rv == 0);
 	}
diff --git a/Kernel/arch/armv7/proc.S b/Kernel/arch/armv7/proc.S
index d1bb091f..801909c9 100644
--- a/Kernel/arch/armv7/proc.S
+++ b/Kernel/arch/armv7/proc.S
@@ -35,6 +35,14 @@ KernelThreadHeader:
 	bl Threads_Exit
 	b .
 
+.globl Proc_int_DropToUser
+@ R0: User IP
+@ R1: User SP
+Proc_int_DropToUser:
+	cps #16
+	mov sp, r1
+	mov pc, r0
+
 .globl SwitchTask
 @ R0: New stack
 @ R1: Pointer to where to save old stack
@@ -61,7 +69,7 @@ SwitchTask:
 	bx r2
 
 .return:
-	push {r4-r12,pc}
+	pop {r4-r12,pc}
 
 .extern MM_Clone
 .extern MM_DumpTables
diff --git a/Kernel/arch/armv7/proc.c b/Kernel/arch/armv7/proc.c
index ffc4b570..d61160f0 100644
--- a/Kernel/arch/armv7/proc.c
+++ b/Kernel/arch/armv7/proc.c
@@ -13,8 +13,11 @@
 extern tThread	gThreadZero;
 extern void	SwitchTask(Uint32 NewSP, Uint32 *OldSP, Uint32 NewIP, Uint32 *OldIP, Uint32 MemPtr);
 extern void	KernelThreadHeader(void);	// Actually takes args on stack
+extern void	Proc_int_DropToUser(Uint32 IP, Uint32 SP) NORETURN;
 extern Uint32	Proc_CloneInt(Uint32 *SP, Uint32 *MemPtr);
 extern tVAddr	MM_NewKStack(int bGlobal);	// TODO: Move out into a header
+extern tVAddr	MM_NewUserStack(void);
+extern char	kernel_table0[];
 
 // === PROTOTYPES ===
 void	Proc_IdleThread(void *unused);
@@ -27,6 +30,7 @@ tThread *gpIdleThread = NULL;
 // === CODE ===
 void ArchThreads_Init(void)
 {
+	gThreadZero.MemState.Base = (tPAddr)&kernel_table0 - KERNEL_BASE;
 }
 
 void Proc_IdleThread(void *unused)
@@ -57,11 +61,39 @@ tThread *Proc_GetCurThread(void)
 	return gpCurrentThread;
 }
 
-void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
+void Proc_StartUser(Uint Entrypoint, Uint Base, int ArgC, char **ArgV, int DataSize)
 {
-	Log_Debug("Proc", "Proc_StartUser: (Entrypoint=%p, Bases=%p, ArgC=%i, ...)",
-		Entrypoint, Bases, ArgC);
-	Log_Error("Proc", "TODO: Implement Proc_StartUser");
+	Uint32	*usr_sp;
+	 int	i;
+	char	**envp;
+	tVAddr	delta;
+
+	Log_Debug("Proc", "Proc_StartUser: (Entrypoint=%p, Base=%p, ArgC=%i, ArgV=%p, DataSize=0x%x)",
+		Entrypoint, Base, ArgC, ArgV, DataSize);
+
+	// Write data to the user's stack
+	usr_sp = (void*)MM_NewUserStack();
+	usr_sp -= (DataSize+3)/4;
+	memcpy(usr_sp, ArgV, DataSize);
+	free(ArgV);
+
+	// Adjust user's copy of the arguments
+	delta = (tVAddr)usr_sp -  (tVAddr)ArgV;
+	Log("delta = %x", delta);
+	ArgV = (void*)usr_sp;
+	for(i = 0; ArgV[i]; i ++)	ArgV[i] += delta;
+	envp = &ArgV[i+1];
+	for(i = 0; envp[i]; i ++)	envp[i] += delta;
+	Log("envp = %p", envp);
+	
+	*--usr_sp = (Uint32)envp;
+	*--usr_sp = (Uint32)ArgV;
+	*--usr_sp = (Uint32)ArgC;
+	*--usr_sp = Base;
+	
+	// Drop to user code
+	Log_Debug("Proc", "Proc_int_DropToUser(%p, %p)", Entrypoint, usr_sp);
+	Proc_int_DropToUser(Entrypoint, (Uint32)usr_sp);
 }
 
 tTID Proc_Clone(Uint Flags)
diff --git a/Kernel/arch/armv7/start.S b/Kernel/arch/armv7/start.S
index 089ead5d..ef6ac76a 100644
--- a/Kernel/arch/armv7/start.S
+++ b/Kernel/arch/armv7/start.S
@@ -9,7 +9,7 @@
 interrupt_vector_table:
 ivt_reset:	b _start @ Reset
 ivt_undef:	b .	@ #UD
-ivt_svc:	b SyscallHandler @ SVC (SWI assume)
+ivt_svc:	b SVC_Handler @ SVC (used to be called SWI)
 ivt_prefetch:	b PrefetchAbort	@ Prefetch abort
 ivt_data:	b DataAbort	@ Data abort
 ivt_unused:	b .	@ Not Used
@@ -65,8 +65,29 @@ _ptr_kmain:
 .comm irqstack, 0x1000	@ ; 4KiB Stack
 .comm abortstack, 0x1000	@ ; 4KiB Stack
 
-SyscallHandler:
-	b .
+.extern SyscallHandler
+SVC_Handler:
+@	sub lr, #4
+	srsdb sp!, #19	@ Switch to supervisor mode (DDI0406B D1.6.5) (actually SRSFD)
+	cpsid ifa, #19
+	push {r0-r12}
+
+	ldr r4, [lr,#-4]
+	mvn r5, #0xFF000000
+	and r4, r5
+
+	push {r4}
+
+	mov r0, sp
+	ldr r4, =SyscallHandler
+	blx r4
+	
+	pop {r2}	@ errno
+	pop {r0,r1}	@ Ret/RetHi
+	add sp, #2*4	@ Saved r2/r3
+	
+	pop {r4-r12}
+	rfeia sp!	@ Pop state (actually RFEFD)
 
 .globl gpIRQHandler
 gpIRQHandler:	.long	0