📄 net_util_a.asm
字号:
;********************************************************************************************************; uC/TCP-IP; The Embedded TCP/IP Suite;; (c) Copyright 2003-2006; 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-Cortex-M3; RealView Development Suite; RealView Microcontroller Development Kit (MDK); ARM Developer Suite (ADS); Keil uVision;; Filename : net_util_a.asm; Version : V1.89; Programmer(s) : JDH;********************************************************************************************************; Note(s) : (1) Assumes ARM CPU mode configured for Little Endian.;********************************************************************************************************;********************************************************************************************************; PUBLIC FUNCTIONS;******************************************************************************************************** EXPORT NetUtil_16BitSumDataCalcAlign_32;********************************************************************************************************; CODE GENERATION DIRECTIVES;******************************************************************************************************** AREA |.text|, CODE, READONLY, ALIGN=2 THUMB REQUIRE8 PRESERVE8;*$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_0
NetUtil_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
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -