h6. [[OS SWI Calls]] h6(. » OS_GBPB h2. OS_GBPB h5. (SWI &0C) |_<^{width:4em}. Entry | | |<^. R0 |<^. "Reason code":#reason | |\2<^. Other registers dependent on reason code| |_<^{width:4em}. Exit | | |<^. R0|<^. Preserved| |\2<^. All other registers dependent on reason code| h4. Use The purpose of this call is to read/write a block from/to an open file. h4. Notes The action performed depends on the reason code value in R0. h4(#reason). Reason Codes |_<^{width:4em}. #|_<^{width:4em}. Hex #|_<^. Action| |<^. 1|<^. &01|<^. [[OS_GBPB 1|Write bytes to given pointer]]| |<^. 2|<^. &02|<^. [[OS_GBPB 2|Write bytes to current pointer]]| |<^. 3|<^. &03|<^. [[OS_GBPB 3|Read bytes from given pointer]]| |<^. 4|<^. &04|<^. [[OS_GBPB 4|Read bytes from current pointer]]| |<^. 5|<^. &05|<^. [[OS_GBPB 5|Read name & boot options]]| |<^. 6|<^. &06|<^. [[OS_GBPB 6|Read current dir and privilege byte]]| |<^. 7|<^. &07|<^. [[OS_GBPB 7|Read library dir and privilege byte]]| |<^. 8|<^. &08|<^. [[OS_GBPB 8|Read entries from current dir]]| |<^. 9|<^. &09|<^. [[OS_GBPB 9|Read entries from given dir]]| |<^. 10|<^. &0A|<^. [[OS_GBPB 10|Read entries and info from given dir]]| |<^. 11|<^. &0B|<^. [[OS_GBPB 11|Read entries and full info from given dir]]| |<^. 12|<^. &0C|<^. [[OS_GBPB 12|Read entries and full info with filetype from given dir]]| h4. See also h5. Other languages documentation [[OS_GBPB (français)|Français]] _space in filename is a problem_ [[fr/OS_GBPB|Français]] _with fr/ prefix_