?????????, ????ж????????????
???????????????????????????????д??MCU???棬????ж????????????????????
1. ???÷?????(JTAG/J-link)???????????, ?????, ????????????????, ??????, ????, ??????????????, ???????????????.
2. ?????? PC ??????????????. ????????????, ????????Χ??.
3. ????? CPU ??? RAM (???????? SDRAM)?????????????????????(bin, hex, elf????)???.
4. ??????????????????????????(?? ARM ?? CPSR), ??к?????????????????а????????. ??, u-boot ????е? start.S ????п???????:
[cpp] view plaincopy/*
* the actual start code
*/
start_code:
/*
* set the cpu to SVC32 mode, ???????????, ?????????(??????ο???????)
*/
mrs r0, cpsr
bic r0, r0, #0x1f /* ???λ?? 1 */
orr r0, r0, #0xd3 /* ?? 0 ???λ */
msr cpsr, r0
5. ???????????, ??? PC ???????????(???????????, ?ж?? goto ?????, PC ??????????), ??????????е?????????.
6. ??????и???????, ?????????????????????????, ??????????????????. ??????????????ж???????????. ???????????о????.
?????????????????κ?????, ?????????ж??????????е?, ????????????,CPU????????????, ??????????????????????. ????ж??????????????????????????????????????????.
????admin ?????????2019-06-17
