1 #define xRA 1 /* return address (aka link register) */ 2 #define xSP 2 /* stack pointer */ 3 #define xGP 3 /* global pointer */ 4 #define xTP 4 /* thread pointer */ 5 6 #define xA0 10 /* gpr[10-17] are syscall arguments */ 7 #define xA1 11 8 #define xA2 12 9 #define xA3 13 10 #define xA4 14 11 #define xA5 15 12 #define xA6 16 13 #define xA7 17 /* syscall number goes here */ 14