?? net_util_a.asm
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;********************************************************************************************************; uC/TCP-IP; The Embedded TCP/IP Suite;; (c) Copyright 2003-2007; Micrium, Inc.; Weston, FL;; All rights reserved. Protected by international copyright laws.;; uC/TCP-IP is provided in source form for FREE evaluation, for educational; use or peaceful research. If you plan on using uC/TCP-IP in a commercial; product you need to contact Micrium to properly license its use in your; product. We provide ALL the source code for your convenience and to help; you experience uC/TCP-IP. The fact that the source code is provided does; NOT mean that you can use it without paying a licensing fee.;; Knowledge of the source code may NOT be used to develop a similar product.;; Please help us continue to provide the Embedded community with the finest; software available. Your honesty is greatly appreciated.;********************************************************************************************************;********************************************************************************************************;; NETWORK UTILITY LIBRARY;; ARM; IAR Compiler;; Filename : net_util_a.asm; Version : V1.91; Programmer(s) : JDH;********************************************************************************************************; Note(s) : (1) Assumes ARM CPU mode configured for Little Endian.;********************************************************************************************************;********************************************************************************************************; PUBLIC FUNCTIONS;******************************************************************************************************** PUBLIC NetUtil_16BitSumDataCalcAlign_32;********************************************************************************************************; CODE GENERATION DIRECTIVES;******************************************************************************************************** RSEG CODE:CODE:NOROOT(2) CODE32;$PAGE ;********************************************************************************************************; NetUtil_16BitSumDataCalcAlign_32();; Description : Calculate 16-bit sum on 32-bit word-aligned data.;; Argument(s) : pdata_32 Pointer to 32-bit word-aligned data (see Note #2).;; size Size of data.;; Return(s) : 16-bit sum (see Notes #1 & #3).;; Caller(s) : NetUtil_16BitSumDataCalc().;; This function is an INTERNAL network protocol suite function & SHOULD NOT be called by ; application function(s).;; Note(s) : (1) Computes the sum of consecutive 16-bit values.;; (2) Since many word-aligned processors REQUIRE that multi-octet words be located on word-; aligned addresses, sum calculation REQUIREs that 32-bit words are accessed on addresses; that are multiples of 4 octets.;; (3) The 16-bit sum MUST be returned in Big Endian/Network order.;; See 'net_util.c NetUtil_16BitSumDataCalc() Note #5b'.;; (a) Assumes Little Endian CPU Mode (see 'net_util_a.asm Note #1') thus requiring the ; 16-bit octets of the 32-bit data to be swapped.;; #### However, the 16-bit octets COULD be swapped after the 16-bit sum is fully ; calculated.;********************************************************************************************************; CPU_INT32U NetUtil_16BitSumDataCalcAlign_32 (void *pdata_32, @ ==> R0; CPU_INT32U size) @ ==> R1; @ sum ==> R2NetUtil_16BitSumDataCalcAlign_32: STMFD SP!, {R2-R12} MOV R2, #0 B NetUtil_16BitSumDataCalcAlign_32_0NetUtil_16BitSumDataCalcAlign_32_1: LDMIA R0!, {R5-R12} ; Calc sum of sixteen 16-bit words ... ; ... using eight 32-bit CPU regs. MOV R3, R5, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R5, LSL #16 MOV R3, R3, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R6, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R6, LSL #16 MOV R3, R3, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R7, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R7, LSL #16 MOV R3, R3, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2;$PAGE MOV R3, R8, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R8, LSL #16 MOV R3, R3, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R9, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R9, LSL #16 MOV R3, R3, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R10, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R10, LSL #16 MOV R3, R3, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R11, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R11, LSL #16 MOV R3, R3, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R12, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R12, LSL #16 MOV R3, R3, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 SUB R1, R1, #(4*8*1)NetUtil_16BitSumDataCalcAlign_32_0: CMP R1, #(4*8*1) ; end of loop BCS NetUtil_16BitSumDataCalcAlign_32_1 B NetUtil_16BitSumDataCalcAlign_32_2;$PAGE NetUtil_16BitSumDataCalcAlign_32_3: LDMIA R0!, {R5} ; Calc sum of two 16-bit words ... ; ... using one 32-bit CPU reg. MOV R3, R5, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 MOV R3, R5, LSL #16 MOV R3, R3, LSR #16 MOV R4, R3, LSR #8 AND R3, R3, #0xFF ORR R4, R4, R3, LSL #8 ADD R2, R4, R2 SUB R1, R1, #(4*1*1)NetUtil_16BitSumDataCalcAlign_32_2: CMP R1, #(4*1*1) ; end of loop BCS NetUtil_16BitSumDataCalcAlign_32_3 MOV R0, R2 LDMFD SP!, {R2-R12} BX LR ; return END?? 快捷鍵說明
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