108
edits
Changes
Adding ARM SVC syscalls
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|-
|-
| 0x93 || || ||
| 0x93 || || ||
+|}
+
+== Syscalls (via ARM syscall instruction) ==
+These types of syscalls are created with the ARM syscall instruction. The exception handler is empty and just do nothing and returns. These syscalls are [http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0471c/Bgbjhiea.html RealView semihosting operations] that allow communication with a debugger. Currently only syscall 0x04 is still used in production versions of IOSU.
+
+<source lang="c">
+MOVS r0, #syscall_number
+SVC 0xAB
+</source>
+
+Register r0 takes the syscall number.
+Register r1 takes the first parameter.
+
+{|border=1
+|-
+! ID # !! Internal name !! Description !! Return value
+|-
+| 0x04 || write(const char *string) || Prints a null-terminated debug message || None
+|-
+| 0x05 || || unused ||
+|-
+| 0x06 || || unused ||
+|-
+| 0x07 || || unused ||
+|-
+| 0x08 || || unused ||
+|-
+| 0x09 || || unused ||
+|-
+| 0x0A || || unused ||
+|-
+| 0x0C || || unused ||
+|-
+| 0x0D || || unused ||
+|-
+| 0x0E || || unused ||
+|-
+| 0x0F || || unused ||
+|-
+| 0x10 || || unused ||
+|-
+| 0x11 || || unused ||
+|-
+| 0x12 || || unused ||
+|-
+| 0x13 || || unused ||
+|-
+| 0x15 || || unused ||
+|-
+| 0x16 || || unused ||
+|-
+| 0x30 || || unused ||
+|-
+| 0x31 || || unused ||
|}
|}