kernel/eka/klib/arm/ckdes8.cia
changeset 0 a41df078684a
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-1:000000000000 0:a41df078684a
       
     1 // Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).
       
     2 // All rights reserved.
       
     3 // This component and the accompanying materials are made available
       
     4 // under the terms of the License "Eclipse Public License v1.0"
       
     5 // which accompanies this distribution, and is available
       
     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
       
     7 //
       
     8 // Initial Contributors:
       
     9 // Nokia Corporation - initial contribution.
       
    10 //
       
    11 // Contributors:
       
    12 //
       
    13 // Description:
       
    14 // e32\klib\arm\ckdes8.cia
       
    15 // 
       
    16 //
       
    17 
       
    18 #include <e32cia.h>
       
    19 #include <arm.h>
       
    20 #include <kernel/kernel.h>
       
    21 
       
    22 #ifdef __DES8_MACHINE_CODED__
       
    23 
       
    24 GLREF_C void KUDesInfoPanicBadDesType();
       
    25 GLREF_C void KUDesSetLengthPanicBadDesType();
       
    26 GLREF_C void KUDesSetLengthPanicOverflow();
       
    27 GLREF_C void Des8PanicBadDesType();
       
    28 
       
    29 /**
       
    30 Gets information about the specified descriptor.
       
    31 
       
    32 If the current thread is a user thread, i.e. if the mode in spsr_svc is 'User',
       
    33 then the descriptor is read using user mode privileges.
       
    34 
       
    35 @param aSrc The descriptor for which information is to be fetched.
       
    36 @param aLength On return, set to the length of the descriptor.
       
    37 @param aMaxLength On return, set to the maximum length of the descriptor,
       
    38                   or 1 if the descriptor is not writable.
       
    39 
       
    40 @return Address of first byte in descriptor.
       
    41 
       
    42 @panic KERN-EXEC 33, if aSrc is not a valid descriptor type.
       
    43 
       
    44 @pre  Do not call from User thread if in a critical section.
       
    45 @pre  Interrupts must be enabled.
       
    46 @pre  Kernel must be unlocked.
       
    47 @pre  No fast mutex can be held.
       
    48 @pre  Call in a thread context.
       
    49 @pre  Can be used in a device driver.
       
    50 */
       
    51 EXPORT_C __NAKED__ const TUint8* Kern::KUDesInfo(const TDesC8& /*aSrc*/, TInt& /*aLength*/, TInt& /*aMaxLength*/)
       
    52 //
       
    53 // Get information about a user descriptor
       
    54 //
       
    55 	{
       
    56 	ASM_CHECK_PRECONDITIONS(MASK_NO_CRITICAL_IF_USER|MASK_INTERRUPTS_ENABLED|MASK_KERNEL_UNLOCKED|MASK_NOT_ISR|MASK_NOT_IDFC|MASK_NO_FAST_MUTEX);
       
    57 	ASM_ASSERT_DATA_PAGING_SAFE		// todo: should this be ASM_ASSERT_PAGING_SAFE?
       
    58 
       
    59 	asm("mrs ip, spsr ");
       
    60 	asm("tst ip, #0x0f ");			// test for user or supervisor
       
    61 	USER_MEMORY_GUARD_OFF(eq,r12,r12);
       
    62 	asm("ldreqt r3, [r0], #4 ");	// if user r3=type/len
       
    63 	USER_MEMORY_GUARD_ON(eq,r12,r12);
       
    64 	asm("bne 1f ");					// branch if supervisor
       
    65 	asm("bic ip, r3, #0xf0000000 ");	// ip=length
       
    66 	asm("str ip, [r1] ");			// store length
       
    67 	asm("mvn ip, #0 ");				// ip=max length=-1 if not writeable
       
    68 	asm("cmp r3, #0x50000000 ");
       
    69 	asm("bcs  " CSM_Z24KUDesInfoPanicBadDesTypev);
       
    70 	asm("eor r3, r3, r3, lsr #1 ");
       
    71 	asm("msr cpsr_flg, r3 ");
       
    72 	USER_MEMORY_GUARD_OFF(,r1,r1);
       
    73 	asm("ldrcst ip, [r0], #4 ");	// if writeable ip=max length and r0+=4
       
    74 	asm("mov r1, r0 ");				// NB can't use ldrlet r0, [r0] - see ARM ARM
       
    75 	asm("ldrlet r0, [r1] ");		// if pointer, r0=pointer field
       
    76 	USER_MEMORY_GUARD_ON(,r1,r1);
       
    77 
       
    78 	asm("2: ");
       
    79 	asm("str ip, [r2] ");			// store max length
       
    80 	asm("addeq r0, r0, #4 ");		// if BufCPtr, step r0 past TBufC length
       
    81 	__JUMP(,lr);
       
    82 
       
    83 	asm("1: ");
       
    84 	asm("ldr r3, [r0], #4 ");		// r3=type/len
       
    85 	asm("bic ip, r3, #0xf0000000 ");	// ip=length
       
    86 	asm("str ip, [r1] ");			// store length
       
    87 	asm("mvn ip, #0 ");				// ip=max length=-1 if not writeable
       
    88 	asm("cmp r3, #0x50000000 ");
       
    89 	asm("bcs  " CSM_Z24KUDesInfoPanicBadDesTypev);
       
    90 	asm("eor r3, r3, r3, lsr #1 ");
       
    91 	asm("msr cpsr_flg, r3 ");
       
    92 	asm("ldrcs ip, [r0], #4 ");		// if writeable ip=max length and r0+=4
       
    93 	asm("ldrle r0, [r0] ");			// if pointer, r0=pointer field
       
    94 	asm("b 2b ");
       
    95 	}
       
    96 
       
    97 
       
    98 /**
       
    99 Sets the length of the specified descriptor.
       
   100 
       
   101 If the current thread is a user thread, i.e. if the mode in spsr_svc is 'User',
       
   102 then the length is written using user mode privileges.
       
   103 
       
   104 @param aDes The descriptor.
       
   105 @param aLength The new descriptor length.
       
   106 
       
   107 @panic KERN-EXEC 34, if aDes is not a modifiable descriptor type.
       
   108 @panic KERN-EXEC 35, if aLength is longer that the maximum length of aDes.
       
   109 
       
   110 @pre  Do not call from User thread if in a critical section.
       
   111 @pre  Interrupts must be enabled.
       
   112 @pre  Kernel must be unlocked.
       
   113 @pre  No fast mutex can be held.
       
   114 @pre  Call in a thread context.
       
   115 @pre  Can be used in a device driver.
       
   116 
       
   117 @post The length of aDes is equal to aLength.
       
   118 @post If aDes is a TPtr type then its maximum length is equal its new length.
       
   119 */
       
   120 EXPORT_C __NAKED__ void Kern::KUDesSetLength(TDes8& /*aDes*/, TInt /*aLength*/)
       
   121 //
       
   122 // Set the length of a user descriptor, checking the length is O.K.
       
   123 //
       
   124 	{
       
   125 	ASM_CHECK_PRECONDITIONS(MASK_NO_CRITICAL_IF_USER|MASK_INTERRUPTS_ENABLED|MASK_KERNEL_UNLOCKED|MASK_NOT_ISR|MASK_NOT_IDFC|MASK_NO_FAST_MUTEX);
       
   126 	ASM_ASSERT_DATA_PAGING_SAFE
       
   127 
       
   128 	asm("mrs ip, spsr ");
       
   129 	asm("tst ip, #0x0f ");
       
   130 	asm("bne  " CSM_ZN5TDes89SetLengthEi);
       
   131 	USER_MEMORY_GUARD_OFF(,r12,r12);
       
   132 	asm("ldrt r2, [r0], #4 ");			// r2=length/type, r0->maxlength
       
   133 	asm("ldrt r3, [r0], #-4 ");			// r3=maxlength, r0->length/type
       
   134 	asm("and r2, r2, #0xf0000000 ");	// r2=type field
       
   135 	asm("cmp r2, #0x20000000 ");		// check for writeable descriptor
       
   136 	USER_MEMORY_GUARD_ON(cc,r12,r12);
       
   137 	asm("bcc  " CSM_Z29KUDesSetLengthPanicBadDesTypev);
       
   138 	asm("cmp r1, r3 ");					// check length
       
   139 	USER_MEMORY_GUARD_ON(hi,r12,r12);
       
   140 	asm("bhi  " CSM_Z27KUDesSetLengthPanicOverflowv);
       
   141 	asm("cmp r2, #0x40000000 ");		// check for EBufCPtr
       
   142 	asm("orr r2, r2, r1 ");				// r2=type + new length
       
   143 	asm("strt r2, [r0], #8 ");			// store new length, r0->ptr if EBufCPtr
       
   144 	USER_MEMORY_GUARD_ON(ne,r12,r12);
       
   145 	__JUMP(ne,lr);						// if not EBufCPtr finished
       
   146 	asm("ldrt r2, [r0] ");				// r2=pointer to TBufCBase
       
   147 	asm("strt r1, [r2] ");				// update length of TBufCBase
       
   148 	USER_MEMORY_GUARD_ON(,r12,r12);
       
   149 	__JUMP(,lr);
       
   150   	}
       
   151 
       
   152 
       
   153 /**
       
   154 Checks whether the specified name is a valid Kernel-side object name.
       
   155 
       
   156 A name is invalid, if it contains non-ascii characters, or any of
       
   157 the three characters: "*", "?", ":".
       
   158 
       
   159 @param  aName The name to be checked.
       
   160 
       
   161 @return KErrNone, if the name is valid; KErrBadName, if the name is invalid.
       
   162 
       
   163 @pre Calling thread can be either in a critical section or not.
       
   164 @pre Interrupts must be enabled.
       
   165 @pre Kernel must be unlocked.
       
   166 @pre No fast mutex can be held.
       
   167 @pre Call in a thread context.
       
   168 @pre Can be used in a device driver.
       
   169 */
       
   170 #ifndef __KERNEL_MODE__
       
   171 #error "TDesC is not 8-bit as __KERNEL_MODE__ is not defined (see e32cmn.h)"
       
   172 #endif
       
   173 __NAKED__ EXPORT_C TInt Kern::ValidateName(const TDesC& /*aName*/)
       
   174 //
       
   175 // Check for : * or ? in descriptor, return KErrBadName if found
       
   176 //
       
   177 	{
       
   178 	ASM_CHECK_PRECONDITIONS(MASK_INTERRUPTS_ENABLED|MASK_KERNEL_UNLOCKED|MASK_NOT_ISR|MASK_NOT_IDFC|MASK_NO_FAST_MUTEX);
       
   179 
       
   180 	asm("ldr r2, [r0], #4 ");			// r2=length/type
       
   181 	asm("cmp r2, #0x50000000 ");
       
   182 	asm("bcs " CSM_Z19Des8PanicBadDesTypev );
       
   183 	asm("bics r3, r2, #0xF0000000 ");	// r3=length
       
   184 	asm("moveq r0, #0 ");				// if length=0, return KErrNone
       
   185 	__JUMP(eq,lr);
       
   186 	asm("eor r2, r2, r2, lsr #1 ");
       
   187 	asm("msr cpsr_flg, r2 ");
       
   188 	asm("addcs r0, r0, #4 ");
       
   189 	asm("ldrle r0, [r0] ");
       
   190 	asm("addeq r0, r0, #4 ");			// r0=this.Ptr()
       
   191 	asm("1: ");
       
   192 	asm("ldrb r1, [r0], #1 ");			// r1=*r0++
       
   193 	asm("cmp r1, #0x20 ");				// is it < 0x20 ?
       
   194 	asm("rsbhss r2, r1, #0x7f ");		// if not, compare 0x7f with char
       
   195 	asm("bls 2f ");						// if char < 0x20 or 0x7f <= char, error
       
   196 	asm("cmp r1, #'*' ");				// is it *
       
   197 	asm("cmpne r1, #':' ");				// if not, is it :
       
   198 	asm("cmpne r1, #'?' ");				// if not, is it ?
       
   199 	asm("subnes r3, r3, #1 ");			// if none of these, decrement length
       
   200 	asm("bne 1b ");
       
   201 	asm("2: ");
       
   202 	asm("cmp r3, #0 ");					// reached end of string?
       
   203 	asm("moveq r0, #0 ");				// if we did, return KErrNone
       
   204 	asm("mvnne r0, #%a0" : : "i" (~KErrBadName));	// else return KErrBadName
       
   205 	__JUMP(,lr);
       
   206 	}
       
   207 
       
   208 extern "C" EXPORT_C __NAKED__ TInt memicmp(const TAny* /*aLeft*/, const TAny* /*aRight*/, TUint /*aLength*/)
       
   209     {
       
   210 	// r0 = aLeft, r1 = aRight, r2 = aLength
       
   211 	asm("str r4, [sp, #-4]! ");
       
   212 	asm("add r2, r2, #1 ");
       
   213 
       
   214 	asm("1: ");
       
   215 	asm("subs r2, r2, #1 ");
       
   216 	asm("ldrneb r3, [r0], #1 ");
       
   217 	asm("beq 0f ");
       
   218 	asm("ldrb r4, [r1], #1 ");
       
   219 	asm("orr ip, r3, #0x20 ");
       
   220 	asm("cmp ip, #0x61 ");
       
   221 	asm("rsbcss ip, ip, #0x7a ");
       
   222 	asm("eors ip, r3, r4 ");
       
   223 	asm("andcss ip, ip, #0xdf ");
       
   224 	asm("beq 1b ");
       
   225 	asm("orrcs r3, r3, #0x20 ");
       
   226 	asm("cmp r4, #0x41 ");
       
   227 	asm("rsbcss ip, r4, #0x5a ");
       
   228 	asm("orrcs r4, r4, #0x20 ");
       
   229 	asm("subs r0, r3, r4 ");
       
   230 	asm("0: ");
       
   231 	asm("moveq r0, #0 ");
       
   232 	asm("ldr r4, [sp], #4 ");
       
   233 	__JUMP(,lr);
       
   234 	}
       
   235 #endif
       
   236 
       
   237 
       
   238 
       
   239