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[Bug 1001443] New: LPC17XX may be definitely locked if address 0x2FChas valid Code Read Protection value


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           Summary: LPC17XX may be definitely locked if address 0x2FC has
                    valid Code Read Protection value
           Product: eCos
           Version: CVS
          Platform: Other (please specify)
        OS/Version: Cortex-M
            Status: UNCONFIRMED
          Severity: major
          Priority: low
         Component: HAL
        AssignedTo: unassigned@bugs.ecos.sourceware.org
        ReportedBy: bernard.fouche@kuantic.com
                CC: ecos-bugs@ecos.sourceware.org
             Class: Advice Request


See section 32.6 of UM10360: if by lack of luck address 0x2FC holds some
magical value (defined has CRP1, CRP2 and CRP3, respectively 0x12345678,
0x87654321 and 0x43218765) then one may lose access to the MCU.

CRP1: removes JTAG access + add ISP (UART0 programming) limitations
CRP2: CRP1 + more ISP limitations
CRP3: CRP2 + no more ISP unless application makes it available.

It is very possible that some application has one of these magical values
exactly at the wrong place and in case of CRP3 the only solution may be to
replace the MCU.

In my current setup using only FLASH on a LPC1765, 0x2FC is right in the middle
of  main().

I guess the solution is in the linker script (I'm not familiar with it)... one
should also be able to lock the MCU if wanted but this could be done by
eventually adding or modifying data in the .hex/.bin file about to be flashed.

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