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Hello,
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I have been working on riscose[1] and have come across an odd usage of OS_Control in some very old code. R0 is being passed with bit 31 set. I have two questions.
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1) Is OSLib able to represent an argument being a code pointer being OR'd with flags? I remember there being some calls which did in 26 bit times, but cannot find today.
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2) Might anyone remember what the flag would indicate? It's not documented in the online PRMs. The RISC OS 2 source has a BIC with 0xfc000003 before jumping to the error handler, which suggests to me that at some point those bits were used for something.
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<a href="http://www.riscos.com/support/developers/prm/progenv.html#88693">http://www.riscos.com/support/developers/prm/progenv.html#88693</a>
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Cheers,
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Dave
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[1] <a href="https://repo.or.cz/riscose.git">https://repo.or.cz/riscose.git</a>
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