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- In our case, the boot code starts at
startup- Other names are
start,download_entryand__rtems_entry_point
- Other names are
- Boot code vaguely follows the "Initialization Software Requirements" outlined in the PowerPPC 440x5 Embedded Processor Core User's Manual v7.1 from IBM
- Why only "vaguely"?
- Clear MSR
- Disable debug events
- Configure instruction and data cache registers
- Set up decrementer and timer registers
- Clear exception registers ECR and XER
- Invalidate instruction and data caches
- Clear the CPU reservation bit
- Set up CCR0, CCR1, MMUCR, CRF
and CTR - Set up TLB pages
- Set up debug events
- Set up EABI and SYSV environment
- Clear out BSS section
- Load vector offset register
- Set up TOC ( overwrites r2 overwritten?)
- Set up initial stack
- Set up argument registers r3, r4 and r5
- Branch to
boot_card()
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