> -----Original Message----- > From: openocd-development-boun...@lists.berlios.de [mailto:openocd- > development-boun...@lists.berlios.de] On Behalf Of Igor Skochinsky > Sent: woensdag 16 december 2009 16:01 > To: Marcelo Utikawa da Fonseca > Cc: openocd-development@lists.berlios.de > Subject: Re: [Openocd-development] Problem when tryng to flash LPC2368 > > Hello Marcelo, > > What you see is bootrom code that gets automatically mapped to 0 if > there is no user code or it's invalid. > > "The interrupt vectors residing in the boot block of the on-chip flash > memory also become active after reset, i.e., the bottom 64 bytes of > the boot block are also visible in the memory region starting from the > address 0x0000 0000. The reset vector contains a jump instruction to > the entry point of the flash boot loader software." > > 00000000 LDR R4, =0x3FFF8000 > 00000004 LDR R5, =0xFFFFBFFF > 00000008 LDR R6, [R4] > 0000000C AND R6, R5, R6 > 00000010 STR R6, [R4] > 00000014 LDR PC, =0x7FFFE040 > > 0x7FFFE040 is the bootrom entrypoint. > > "3.1.1 Criterion for Valid User Code > Criterion for valid user code: The reserved ARM interrupt vector > location (0x0000 0014) should contain the 2's complement of the > check-sum of the remaining interrupt vectors. This causes the checksum > of all of the vectors together to be 0. The boot loader code disables > the overlaying of the interrupt vectors from the boot block, then > checksums the interrupt vectors in sector 0 of the flash. If the > signatures match then the execution control is transferred to the user > code by loading the program counter with 0x0000 0000. Hence the user > flash reset vector should contain a jump instruction to the entry > point of the user application code." > > My guess is that FlashMagic automatically patches the checksum to be > correct.
IIRC OpenOCD should do this or has this function been deleted? I recall some discussion about that but I don't remember the outcome. I can't imagine OpenOCD doesn't calculate the checksum. All compiler / linker tools more or less assume the programming software takes care of creating the checksum. Nico Coesel _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
