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Lander on the Acorn Archimedes

Copy protection: DecryptGameBinary

Name: DecryptGameBinary [Show more] Type: Subroutine Category: Copy protection Summary: Placeholder routine to decrypt game code to &8000 so it can be run
Context: See this subroutine in context in the source code References: This subroutine is called as follows: * RunImageEntry calls DecryptGameBinary
.DecryptGameBinary LDR R0, gameCodeAddr \ Set R0 to the address of the game code LDR R1, absoluteAddr \ Set R1 to the address of the start of the \ Absolute file LDR R2, gameCodeEndAddr \ Set R2 to the address of the end of the \ game code .decr1 LDR R12, [R0], #4 \ Copy a word from R0 to R1, updating the STR R12, [R1], #4 \ addresses as we go (this is where the \ decryption process would work, but \ currently it is just a copy) CMP R0, R2 \ Loop back until we have copied the whole BNE decr1 \ game B Entry \ Start the game by jumping to the Entry \ routine