portasm.lst

本代码已经经过修改

                                first item on the stack.    
   32.8  00000090                      ; Load it into the ulCriticalNesting
                                variable.                                 
                                
   32.9  00000090 A0009FE5             LDR             R0, =ulCriticalNesting
   32.10 00000094 0200BEE8             LDMFD   LR!, {R1}
   32.11 00000098 001080E5             STR             R1, [R0]
   32.12 0000009C              
   32.13 0000009C                      ; Get the SPSR from the stack.          
                                                                               
                                       
   32.14 0000009C 0100BEE8             LDMFD   LR!, {R0}
   32.15 000000A0 00F06FE1             MSR             SPSR_cxsf, R0
   32.16 000000A4              
   32.17 000000A4                      ; Restore all system mode registers for
                                the task.                              
                                
   32.18 000000A4 FF7FDEE8             LDMFD   LR, {R0-R14}^
   32.19 000000A8 0000A0E1             NOP
   32.20 000000AC              
   32.21 000000AC                      ; Restore the return address.           
                                                                               
                                       
   32.22 000000AC 3CE09EE5             LDR             LR, [LR, #+60]
   32.23 000000B0              
   32.24 000000B0                      ; And return - correcting the offset in
                                the LR to obtain the    
   32.25 000000B0                      ; correct address.                      
                                                                               
                                                       
   32.26 000000B0 04F05EE2             SUBS    PC, LR, #4
   32.27 000000B4              
   32.28 000000B4                      ENDM
   33    000000B4              
   34    000000B4              ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
                               ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   35    000000B4              ; Preemptive context switch function.  This will
                                only ever get used if
   36    000000B4              ; portUSE_PREEMPTION is set to 1 in portmacro.h.
   37    000000B4              ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
                               ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   38    000000B4              vPortPreemptiveTickISR:
   39    000000B4                      portSAVE_CONTEXT                       
                                ; Save the context of the current task.
   39.1  000000B4              
   39.2  000000B4                      ; Push R0 as we are going to use the
                                register.                                 
                                
   39.3  000000B4 01002DE9             STMDB   SP!, {R0}
   39.4  000000B8              
   39.5  000000B8                      ; Set R0 to point to the task stack
                                pointer.                                   
                                
   39.6  000000B8 00204DE9             STMDB   SP, {SP}^
   39.7  000000BC 04D04DE2             SUB             SP, SP, #4
   39.8  000000C0 0100BDE8             LDMIA   SP!, {R0}
   39.9  000000C4              
   39.10 000000C4                      ; Push the return address onto the
                                stack.                                         
                                     
   39.11 000000C4 004020E9             STMDB   R0!, {LR}
   39.12 000000C8              
   39.13 000000C8                      ; Now we have saved LR we can use it
                                instead of R0.                            
                                
   39.14 000000C8 00E0A0E1             MOV             LR, R0
   39.15 000000CC              
   39.16 000000CC                      ; Pop R0 so we can save it onto the
                                system mode stack.                  
   39.17 000000CC 0100BDE8             LDMIA   SP!, {R0}
   39.18 000000D0              
   39.19 000000D0                      ; Push all the system mode registers
                                onto the task stack.               
   39.20 000000D0 FF7F4EE9             STMDB   LR, {R0-LR}^
   39.21 000000D4 3CE04EE2             SUB             LR, LR, #60
   39.22 000000D8              
   39.23 000000D8                      ; Push the SPSR onto the task stack.    
                                                                              
                                
   39.24 000000D8 00004FE1             MRS             R0, SPSR
   39.25 000000DC 01002EE9             STMDB   LR!, {R0}
   39.26 000000E0              
   39.27 000000E0 50009FE5             LDR             R0, =ulCriticalNesting
  
   39.28 000000E4 000090E5             LDR             R0, [R0]
   39.29 000000E8 01002EE9             STMDB   LR!, {R0}
   39.30 000000EC              
   39.31 000000EC                      ; Store the new top of stack for the
                                task.                                          
                                   
   39.32 000000EC 40109FE5             LDR             R1, =pxCurrentTCB
   39.33 000000F0 000091E5             LDR             R0, [R1]
   39.34 000000F4 00E080E5             STR             LR, [R0]
   39.35 000000F8              
   39.36 000000F8                      ENDM
   40    000000F8              
   41    000000F8 40009FE5             LDR R0, =vPortPreemptiveTick ; Increment
                                                                     the tick
                                                                     count -
                                                                     this may
                                                                     wake a
                                                                     task.
   42    000000FC 0FE0A0E1             MOV lr, pc
   43    00000100 10FF2FE1             BX R0
   44    00000104              
   45    00000104                      portRESTORE_CONTEXT                    
                                ; Restore the context of the selected
                                task.
   45.1  00000104              
   45.2  00000104                      ; Set the LR to the task stack.         
                                                                               
                                               
   45.3  00000104 28109FE5             LDR             R1, =pxCurrentTCB
   45.4  00000108 000091E5             LDR             R0, [R1]
   45.5  0000010C 00E090E5             LDR             LR, [R0]
   45.6  00000110              
   45.7  00000110                      ; The critical nesting depth is the
                                first item on the stack.    
   45.8  00000110                      ; Load it into the ulCriticalNesting
                                variable.                                 
                                
   45.9  00000110 20009FE5             LDR             R0, =ulCriticalNesting
   45.10 00000114 0200BEE8             LDMFD   LR!, {R1}
   45.11 00000118 001080E5             STR             R1, [R0]
   45.12 0000011C              
   45.13 0000011C                      ; Get the SPSR from the stack.          
                                                                               
                                       
   45.14 0000011C 0100BEE8             LDMFD   LR!, {R0}
   45.15 00000120 00F06FE1             MSR             SPSR_cxsf, R0
   45.16 00000124              
   45.17 00000124                      ; Restore all system mode registers for
                                the task.                              
                                
   45.18 00000124 FF7FDEE8             LDMFD   LR, {R0-R14}^
   45.19 00000128 0000A0E1             NOP
   45.20 0000012C              
   45.21 0000012C                      ; Restore the return address.           
                                                                               
                                       
   45.22 0000012C 3CE09EE5             LDR             LR, [LR, #+60]
   45.23 00000130              
   45.24 00000130                      ; And return - correcting the offset in
                                the LR to obtain the    
   45.25 00000130                      ; correct address.                      
                                                                               
                                                       
   45.26 00000130 04F05EE2             SUBS    PC, LR, #4
   45.27 00000134              
   45.28 00000134                      ENDM
   46    00000134              
   47    00000134              
   48    00000134                      END
   48.1  00000134                       TABLE
   48.2  00000134 ........             Reference on line 18,28,32,39,45
                                            
   48.3  00000138 ........             Reference on line 18,28,32,39,45
                                            
   48.4  0000013C ........             Reference on line 29 
   48.5  00000140 ........             Reference on line 41 
   48.6  00000144                      END (including table)
##############################
#          CRC:39B5          #
#        Errors:   0         #
#        Warnings: 0         #
#         Bytes: 324         #
##############################