bootloader代码分析报告.doc

Bootloader代码分析报告徐 凯2007-8-3Bootloader代码分析报告11.启动代码分析11.1.vector.s代码分析11.1.1.宏定义51.1.3.判断是否是thumb指令61.1.4.定义新程序、引入新符号61.1.5.定义新程序、引入新符号71.1.6.定义系统异常向量表71.1.7.程序跳转宏定义71.1.8.异常处理程序定义71.1.9.声明C主函数程序入口101.1.10.定义vector.s中需要用到的连接器变量101.1.11.定义从FLASH启动程序的函数111.2.sysinit.s代码分析111.2.1.引入S3C4510相关系统配置寄存器的地址181.2.2.定义用于配置ROM和RAM的宏181.2.3.定义用于配置SYSCFG的宏181.2.4.定义用于初始化内存的函数InitMemory181.2.5.定义用于初始化内存的函数InitMemory201.2.6.定义内存重设置函数ResetMemSet211.2.7.初始化21种中断源响应函数InitInterrupt211.2.8.初始化18个外部I/O端口函数InitPort211.2.9.初始化2个计时器的函数InitTimer221.2.10.初始化2个串口函数InitUart221.2.11.初始化栈函数InitStack231.2.12.系统初始化函数InitSystem241. 启动代码分析1.1. vector.s代码分析由于连接器参数中有-first vector.o，所以先从这个文件开始分析。首先，列出源代码：1 ModeMask EQU0x1F2 SVC32ModeEQU0x133 IRQ32ModeEQU0x124 FIQ32ModeEQU0x115 User32ModeEQU0x106 Abort32ModeEQU0x177 Undef32ModeEQU0x1B8 IRQ_BITEQU0x809 FIQ_BITEQU0x4010 ;RomBaseAddrEQU011 RamBaseAddrEQU&10012 ;RamEndAddr EQU&20013 GBLSMainEntry14 MainEntrySETSmain15 IMPORT$MainEntry16 ;*17 ;鯡tasm.exe默18 GBLL THUMBCODE19 CONFIG = 1620 THUMBCODE SETLTRUE21 CODE3222 | 23 THUMBCODE SETLFALSE24 2526 THUMBCODE27 CODE32 ;for start-up code for Thumb mode28 2930 ;*31 AREASelfBoot,CODE,READONLY3233 IMPORTUDF_INS_VECTOR34 IMPORTSWI_SVC_VECTOR35 IMPORTINS_ABT_VECTOR36 IMPORTDAT_ABT_VECTOR37 IMPORTIRQ_SVC_VECTOR38 IMPORTFIQ_SVC_VECTOR3940 ENTRY41 IF :DEF: |ads$version|42 ELSE43 EXPORT_main44 _main45 ENDIF46 ResetEntry47 bSYS_RST_HANDLER48 bUDF_INS_HANDLER49 bSWI_SVC_HANDLER50 bINS_ABT_HANDLER51 bDAT_ABT_HANDLER52 b.53 bIRQ_SVC_HANDLER54 bFIQ_SVC_HANDLER5556 ;*57 MACRO58 $LabelHANDLER$Vector59 $Label60 sublr, lr, #461 stmfdsp!, r0-r3, lr62 ldrr0, =$Vector63 ldrpc, r064 ldmfdsp!, r0-r3, pc65 MEND6667 UDF_INS_HANDLER68 stmfdsp!, r0-r3, lr69 ldrr0, =UDF_INS_VECTOR70 movlr, pc71 ldrpc, r072 ldmfdsp!, r0-r3, pc73 SWI_SVC_HANDLER74 stmfdsp!, r0-r3, lr75 ldrr0, =SWI_SVC_VECTOR76 movlr, pc77 ldrpc, r078 ldmfdsp!, r0-r3, pc79 INS_ABT_HANDLER80 sublr, lr, #481 stmfdsp!, r0-r3, lr82 ldrr0, =INS_ABT_VECTOR83 movlr, pc84 ldrpc, r085 ldmfdsp!, r0-r3, pc86 DAT_ABT_HANDLER87 sublr, lr, #488 stmfdsp!, r0-r3, lr89 ldrr0, =DAT_ABT_VECTOR90 movlr, pc91 ldrpc, r092 ldmfdsp!, r0-r3, pc93 IRQ_SVC_HANDLER94 sublr, lr, #495 stmfdsp!, r0-r12, lr96 mrsr0, spsr97 stmfdsp!, r098 ldrr0, =IRQ_SVC_VECTOR99 ldrpc, r0100 FIQ_SVC_HANDLER101 sublr, lr, #4102 stmfdsp!, r0-r12, lr103 mrsr0, spsr104 stmfdsp!, r0105 ldrr0, =IRQ_SVC_VECTOR106 ldrpc, r0107108 ;*109 SYS_RST_HANDLER110 mrsr0, cpsr;enter svc mode and disable irq,fiq111 bicr0, r0, #ModeMask112 orrr0, r0, #(SVC32Mode :OR: IRQ_BIT :OR: FIQ_BIT)113 msrcpsr_c, r0114115 IMPORTInitSystem116 blInitSystem117118 adrr0, ResetEntry119 movr3, #(RamBaseAddr16)120 ldrr1, BaseOfROM121 ldrr2, TopOfROM122 addr1, r1, r3123 addr2, r2, r3124 0125 ldmiar0!, r4-r11126 stmiar1!, r4-r11127 cmpr1, r2128 bcc%B0129130 subr1, r1, r2131 subr0, r0, r1132 ldrr1, BaseOfBSS133 ldrr2, BaseOfZero134 addr1, r1, r3135 addr2, r2, r3136 1137 cmpr1,r2138 ldrccr4, r0, #4139 strccr4, r1, #4140 bcc%B1141142 movr0,#0143 ldrr2,EndOfBSS144 addr2, r2, r3145 3146 cmpr1,r2147 strccr0, r1, #4148 bcc%B3149150 IMPORTRemapMemory151152 adrr0, ResetEntry153 ldrr1, =RemapMemory154 ldrr2, BaseOfROM155 subr2, r1, r2156 addr0, r0, r2157 addr1, r2, r3158 movr2,#32159 0160 ldrr3, r0, #4161 strr3, r1, #4162 subsr2, r2,#1163 bne%B0164165 ldrlr,GotoMain 166 bRemapMemory 167168 GotoMainDCD$MainEntry169170 ;*171 IMPORT|Image$RO$Base|; ROM code start172 IMPORT|Image$RO$Limit|; RAM data starts after ROM program173 IMPORT|Image$RW$Base|; Pre-initialised variables174 IMPORT|Image$ZI$Base|; uninitialised variables175 IMPORT|Image$ZI$Limit|; End of variable RAM space176177 BaseOfROMDCD|Image$RO$Base|178 TopOfROMDCD|Image$RO$Limit|179 BaseOfBSSDCD|Image$RW$Base|180 BaseOfZeroDCD|Image$ZI$Base|181 EndOfBSSDCD|Image$ZI$Limit|182183 ;*184 TIP_SIZEEQU256185186 IMPORTResetMemSet187 EXPORTtrans_to_boot188 trans_to_boot189 movlr, r1; a2 = r1190 ldrr1, =ResetMemSet191 ldrr2, BaseOfROM192 subr2, r1, r2193 addr0, r0, r2; a1 = r0194 movr2,#TIP_SIZE195 0196 ldrr3, r1, #4197 strr3, r0, #4198 subsr2, r2,#1199 bne%B0200201 subr0, r0, #TIP_SIZE*4202 movpc,r0203204 ;*205206 END1.1.1. 宏定义1ModeMask EQU0x1F2SVC32ModeEQU0x133IRQ32ModeEQU0x124FIQ32ModeEQU0x115User32ModeEQU0x106Abort32ModeEQU0x177Undef32ModeEQU0x1B8IRQ_BITEQU0x809FIQ_BITEQU0x4010;RomBaseAddrEQU011RamBaseAddrEQU&10012;RamEndAddr EQU&200行1定义了CPSR中表示模式位的5位。行2-7定义了6种处理器模式（除system模式）对应的CPSR位。行8-7定义了CPSR中FIQ与IRQ置位。行10、12为注释，行11定义了一个宏，&的意义等于DCD伪指令，其分配一个字的内存，并用100初始化该字的内存，并使用RomBaseAddr标志这段内存的实际地址。1.1.2. 宏定义13GBLSMainEntry14MainEntrySETSmain15IMPORT$MainEntry行13-15声明了一个字符串变量MainEntry,并将其设置为”main”，并引入外部符号”main”。1.1.3. 判断是否是thumb指令18GBLL THUMBCODE19 CONFIG = 1620THUMBCODE SETLTRUE21CODE3222| 23THUMBCODE SETLFALSE242526 THUMBCODE27CODE32 ;for start-up code for Thumb mode28 行18声明了逻辑变量THUMBCODE行19-24执行了一个IF ELSE ENDIF指令，CONFIG变量是1中第88页说明的汇编器域定义变量，如果其为32则说明本文件采用ARM汇编器，相应地把THUMBCODE设置为FALSE，若为16则是使用thumb汇编器，相应地把THUMBCODE设置为TRUE。行26-28，强制执行32位的ARM指令，感觉很奇怪，应该是用CODE16命令才对。1.1.4. 定义新程序、引入新符号31AREASelfBoot,CODE,READONLY3233IMPORTUDF_INS_VECTOR34IMPORTSWI_SVC_VECTOR35IMPORTINS_ABT_VECTOR36IMPORTDAT_ABT_VECTOR37IMPORTIRQ_SVC_VECTOR38IMPORTFIQ_SVC_VECTOR行31定义了一个新的程序段SelfBoot。行33-38引入了一系列的符号，这些符号在sysinit.s中定义并导出。1.1.5. 定义新程序、引入新符号40ENTRY41IF :DEF: |ads$version|42ELSE43EXPORT_main44_main45ENDIF行40首先声明了程序的入口根据1中第89页的说明，行41-45判断程序是给ADS还是SDT执行的，如果是如果是SDT，则导出_main符号，并开始定义_main函数的开始。1.1.6. 定义系统异常向量表46ResetEntry47bSYS_RST_HANDLER48bUDF_INS_HANDLER49bSWI_SVC_HANDLER50bINS_ABT_HANDLER51bDAT_ABT_HANDLER52b.53bIRQ_SVC_HANDLER54bFIQ_SVC_HANDLER行46-54定义了系统异常处理向量表，并在vector.o首次执行时首先执行行47的代码。1.1.7. 程序跳转宏定义57MACRO58$LabelHANDLER$Vector59$Label60sublr, lr, #461stmfdsp!, r0-r3, lr62ldrr0, =$Vector63ldrpc, r064ldmfdsp!, r0-r3, pc65MEND行57-65定义了一个有1个参数的宏HANDLER，该宏实现程序跳转，跳转到$Vector所指向内存所保存的内存地址的值，执行完该函数后，恢复现场，并返回原来的状态。1.1.8. 异常处理程序定义67UDF_INS_HANDLER68stmfdsp!, r0-r3, lr69ldrr0, =UDF_INS_VECTOR70movlr, pc71ldrpc, r072ldmfdsp!, r0-r3, pc73SWI_SVC_HANDLER74stmfdsp!, r0-r3, lr75ldrr0, =SWI_SVC_VECTOR76movlr, pc77ldrpc, r078ldmfdsp!, r0-r3, pc79INS_ABT_HANDLER80sublr, lr, #481stmfdsp!, r0-r3, lr82ldrr0, =INS_ABT_VECTOR83movlr, pc84ldrpc, r085ldmfdsp!, r0-r3, pc86DAT_ABT_HANDLER87sublr, lr, #488stmfdsp!, r0-r3, lr89ldrr0, =DAT_ABT_VECTOR90movlr, pc91ldrpc, r092ldmfdsp!, r0-r3, pc93IRQ_SVC_HANDLER94sublr, lr, #495stmfdsp!, r0-r12, lr96mrsr0, spsr97stmfdsp!, r098ldrr0, =IRQ_SVC_VECTOR99ldrpc, r0100FIQ_SVC_HANDLER101sublr, lr, #4102stmfdsp!, r0-r12, lr103mrsr0, spsr104stmfdsp!, r0105ldrr0, =IRQ_SVC_VECTOR106ldrpc, r0107108;*109SYS_RST_HANDLER110mrsr0, cpsr;enter svc mode and disable irq,fiq111bicr0, r0, #ModeMask112orrr0, r0, #(SVC32Mode :OR: IRQ_BIT :OR: FIQ_BIT)113msrcpsr_c, r0114115IMPORTInitSystem116blInitSystem117118adrr0, ResetEntry119movr3, #(RamBaseAddr16)120ldrr1, BaseOfROM121ldrr2, TopOfROM122addr1, r1, r3123addr2, r2, r31240125ldmiar0!, r4-r11126stmiar1!, r4-r11127cmpr1, r2128bcc%B0129130subr1, r1, r2131subr0, r0, r1132ldrr1, BaseOfBSS133ldrr2, BaseOfZero134addr1, r1, r3135addr2, r2, r31361137cmpr1,r2138ldrccr4, r0, #4139strccr4, r1, #4140bcc%B1141142movr0,#0143ldrr2,EndOfBSS144addr2, r2, r31453146cmpr1,r2147strccr0, r1, #4148bcc%B3149150IMPORTRemapMemory151152adrr0, ResetEntry153ldrr1, =RemapMemory154ldrr2, BaseOfROM155subr2, r1, r2156addr0, r0, r2157addr1, r2, r3158movr2,#321590160ldrr3, r0, #4161strr3, r1, #4162subsr2, r2,#1163bne%B0164165ldrlr,GotoMain 166bRemapMemory 行67-166定义了7种模式异常的处理函数具体地：UDF_INS_HANDLER 执行UDF_INS_VECTOR内存所保存的指令后，返回到异常发生之前的状态。类似，SWI_SVC_HANDLER, INS_ABT_HANDLER, DAT_ABT_HANDLER, IRQ_SVC_HANDLER, FIQ_SVC_HANDLER也执行类似的操作，执行XX_XX_VECTOR内存所保存的指令，然后返回到异常发生之前的状态。SYS_RST_HANDLER异常处理程序与其它异常处理程序有很大不同，行110-113使得处理器进入SVC模式，并且禁止FIQ与IRQ。行115-116使得程序跳转到sysinit.s中定义的InitSystem函数中执行，并在执行结束后返回。InitSystem函数的作用是进行内存、堆栈、LED端口、串口、定时器以及中断的初始化工作，具体讲解请参见sysinit.s中的分析（1.2.12）。行118将异常向量表ResetEntry的地址保存入r0。行119-128将bootloader的RO段拷贝入内存。行130-140将bootloader的RW段拷贝入内存。行142-148将内存中的ZI段初始化为0。行150-163将RemapMemory函数拷贝入内存中。行165将返回地址进行设置。行166执行RemapMemory函数（在sysinit.s中定义），RemapMemory函数主要是设置ROMCON0、ROMCON1和DRAMCON0、DRAMCON1；并将IRQ_SERVICE函数的地址存入一个内存中的数组中。RemapMemory函数执行完后将跳入bios.c中定义的main函数。1.1.9. 声明C主函数程序入口168GotoMainDCD$MainEntry行168声明了GotoMain标号，其被定义为变量$MainEntry的值“main”1.1.10. 定义vector.s中需要用到的连接器变量根据文献2第56-57页中的说明，行170-181引入了由连接器预定义的变量值。170;*171IMPORT|Image$RO$Base|; ROM code start172IMPORT|Image$RO$Limit|; RAM data starts after ROM program173IMPORT|Image$RW$Base|; Pre-initialised variables174IMPORT|Image$ZI$Base|; uninitialised variables175IMPORT|Image$ZI$Limit|; End of variable RAM space176177BaseOfROMDCD|Image$RO$Base|178TopOfROMDCD|Image$RO$Limit|179BaseOfBSSDCD|Image$RW$Base|180BaseOfZeroDCD|Image$ZI$Base|181EndOfBSSDCD|Image$ZI$Limit|1.1.11. 定义从FLASH启动程序的函数184TIP_SIZEEQU256185186IMPORTResetMemSet187EXPORTtrans_to_boot188trans_to_boot189movlr, r1; a2 = r1190ldrr1, =ResetMemSet191ldrr2, BaseOfROM192subr2, r1, r2193addr0, r0, r2; a1 = r0194movr2,#TIP_SIZE1950196ldrr3, r1, #4197strr3, r0, #4198subsr2, r2,#1199bne%B0200201subr0, r0, #TIP_SIZE*4202movpc,r0行184-202定义了从FLASH固定地址BIOS_LOAD0x1000启动程序的函数，似乎是重新启动的程序。1.2. sysinit.s代码分析首先列出sysinit.s的源代码1 INCLUDEs3c4510.s23 RomBaseAddrEQU04 RomEndAddrEQU&205 RamBaseAddrEQU&1006 RamEndAddrEQU&20078 AREAtext, CODE, READONLY910 SFR_BASEEQU0x3ff;0x3ff000011 SRAM_BASEEQU0x3f8;0x3f800001213 ;EXPORTInitMemory14 InitMemory15 ldrr0, =SYSCFG16 ldrr1, =SDRAM_ITF :OR: SFR_BASE16 :OR: SRAM_BASE6 :OR: CACHE_ALL :OR: CACHE_EN17 strr1, r01819 ldrr0, =CLKCON20 ldrr1, =021 strr1, r02223 ldrr0, =EXTACON024 ldrr1, =0x0fff0fff25 strr1, r026 ldrr0, =EXTACON127 ldrr1, =0x0fff0fff28 strr1, r02930 ldrr0, =EXTDBWTH31 ldrr1, =0xffff55632 str r1, r03334 adrr0, MemCfgPara35 ldmiar0, r1-r1136 ldrr0, =ROMCON037 stmiar0, r1-r113839 movpc, r144041 MemCfgPara42 DCDRomBaseAddr10 :OR RomEndAddr20 :OR: &60;&1084006043 DCD&1084206044 DCD&1084206045 DCD&1084206046 DCD&1084206047 DCD&1084206048 DCDRamBaseAddr10 :OR: RamEndAddr20 :OR: &398;&1000039849 DCD&1004039850 DCD&1004039851 DCD&1004039852 DCD&ce2983fd 5354 EXPORTRemapMemory55 RemapMemory56 adrr0, RemapMemPara57 ldmiar0, r1-r1158 ldrr0, =ROMCON059 stmiar0, r1-r1160 nop61 nop62 ldrr0, =IRQ_SVC_VECTOR63 ldrr1, =IRQ_SERVICE;IRQ_SVC_VECTOR in ram, so set it after remap64 str r1, r06566 movpc, r146768 RemapMemPara69 DCD&1204006070 DCD&1084206071 DCD&1084206072 DCD&1084206073 DCD&1084206074 DCD&1084206075 DCD&1000039876 DCD&1004039877 DCD&1004039878 DCD&1004039879 DCD&ce2983fd8081 EXPORTResetMemSet82 ResetMemSet83 adrr0, ResetMemPara84 ldmiar0, r1-r1185 ldr r0, =ROMCON086 stmiar0, r1-r1187 nop88 nop8990 movpc, r149192 ResetMemPara93 DCD&2000006094 DCD&0000006095 DCD&0000006096 DCD&0000006097 DCD&0000006098 DCD&0000006099 DCD&00000000100 DCD&00000000101 DCD&00000000102 DCD&00000000103 DCD&000083fd104105 ;*106 InitInterrupt107 ldrr0, =INTMSK108 ldrr1, =0x3fffff109 strr1, r0;disable all interrupt110111 movpc,r14112113 ;*114 InitPort115 ldrr0, =IOPMOD116 ldrr1, =1117 strr1, r0;all input but p0 output118119 ldrr0, =IOPCON120 ldrr1, =0121 strr1, r0;disable XIRQ 0-3, dma req,ack, timer 0,1 output122123 ldrr0, =IOPDATA124 ldr r1, r0;read input data125126 movpc, r14127128 ;*129 InitTimer130 ldrr0, =TMOD131 ldrr1, =0132 strr1, r0;disable timer 0,1133134 movpc, r14135136 ;*137 UART_DIV_CNT0EQU26138 UART_DIV_CNT1EQU0139140 InitUart141 ldrr0, =ULCON0142 ldrr1, =DATA8b :OR: STOPb1 :OR PARITY_NO143 strr1, r0144145 ldrr0, =UCON0146 ldrr1, =RX_STAT_INT|9147 strr1, r0148 149 ldrr0, =UBRDIV0150 ldrr1, =UART_DIV_CNT04|UART_DIV_CNT1151 strr1, r0;if UART_DIV_CNT1=xxx0 baud rate = MCLK/(UART_DIV_CNT0+1)/16152 ;if UART_DIV_CNT1=xxx1 baud rate = MCLK/(UART_DIV_CNT0+1)/16/16153 ldrr0, =URXBUF0154 ldrr1, r0;read rx data155 156 ldrr0, =ULCON1157 ldrr1, =DATA8b :OR: STOPb1 :OR PARITY_NO158 strr1, r0159 160 ldrr0, =UCON1161 ldrr1, =RX_STAT_INT|9162 strr1, r0163 164 ldrr0, =UBRDIV1165 ldrr1, =UART_DIV_CNT04|UART_DIV_CNT1166 strr1, r0;if UART_DIV_CNT1=xxx0 baud rate = MCLK/(UART_DIV_CNT0+1)/16167 ;if UART_DIV_CNT1=xxx1 baud rate = MCLK/(UART_DIV_CNT0+1)/16/16168 ldrr0, =URXBUF1169 ldrr1, r0;read rx data170 171 movpc, r14172 173 ;*174 InitStack175 mrsr0, cpsr176 bicr0, r0, #PSR_MODE_MASK177 178 orrr1, r0, #PSR_UNDEF_MODE|NO_INT179 msrcpsr_cxsf, r1;UndefMode180 ldrsp,=UndefStack181 182 orrr1, r0, #PSR_ABORT_MODE|NO_INT183 msrcpsr_cxsf, r1;AbortMode184 ldrsp, =AbortStack185 186 orrr1, r0, #PSR_IRQ_MODE|NO_INT187 msrcpsr_cxsf, r1;IRQMode188 ldrsp, =IRQStack189 190 orrr1, r0, #PSR_FIQ_MODE|NO_INT191 msrcpsr_cxsf, r1;FIQMode192 ldrsp, =FIQStack193 194 orrr1, r0, #PSR_SVC_MODE|NO_INT195 msrcpsr_cxsf, r1;SVCMode196 ldrsp, =SVCStack197 198 movpc, r14199200 ;*201 EXPORTInitSystem202 InitSystem203 movr12, r14204 blInitMemory205 blInitStack206 blInitPort207 blInitUart208 blInitTimer209 blInitInterrupt210 ;ldrr0, =0x11000000 ;Cache Flush 211 ;movr1, #0212 ;movr2, #256 213 ;1214 ;strr1, r0, #4215 ;subsr2, r2, #1216 ;bne%B1217 movpc, r12218 219 ;*220 IRQ_SERVICE;using I_ISPR register. 221 IMPORTpIrqStart222 IMPORTpIrqFinish223 IMPORTpIrqHandler224 225 ;nop226 ;ldrr0, =TMOD227 ;ldrr1,r0228 ;andr1,r1, #&37229 ;strr1, r0230 231 ldrr4, =INTOFFSET232 ldrr4, r4233 movr1, r4, lsr #2234 movr0, #1235 movr0, r0, lsl r1236 ldrr1, =INTPND237 strr0, r1;clear interrupt pending bit238 ldrr1, =pIrqStart239 ldrr1, r1240 cmpr1, #0241 movnelr, pc; .+8242 movnepc, r1 243 244 ldrr1, =pIrqHandler245 ldrr1, r1246 cmpr1, #0247 movnelr, pc248 movnepc, r1 249 250 ldrr1, =pIrqFinish251 ldrr1, r1252 cmpr1, #0253 movnelr, pc; .+8254 movnepc, r1255 cmpr0, #0256 movnelr, pc257 movnepc, r0 258 259 ldmfdsp!, r0;IRQ260 msrspsr_cxsf, r0261 ldmfdsp!, r0-r12, pc262 ;*263 AREA HiVector, DATA, READWRITE264 265 _RAM_END_ADDREQU0x01000000266267 (_RAM_END_ADDR-0x600)268 UserStack#256;xxxxxa00269 SVCStack#256;xxxxxb00270 UndefStack#256;xxxxxc00271 AbortStack#256;xxxxxd00272 IRQStack#256;xxxxxe00273 FIQStack#0;xxxxxf00274275276 MAP(_RAM_END_ADDR-0x100)277 SYS_RST_VECTOR#4278 UDF_INS_VECTOR#4279 SWI_SVC_VECTOR#4280 INS_ABT_VECTOR#4281 DAT_ABT_VECTOR#4282 RESERVED_VECTOR#4283 IRQ_SVC_VECTOR#4284 FIQ_SVC_VECTOR#4285286 EXPORTSYS_RST_VECTOR287