Register preservation rules match the ELF ABI calling sequence with the
following differences:
---- For the sc instruction, differences with the ELF ABI ---
-=========== ============= ========================================
-r0 Volatile (System call number.)
-r3 Volatile (Parameter 1, and return value.)
-r4-r8 Volatile (Parameters 2-6.)
-cr0 Volatile (cr0.SO is the return error condition.)
-cr1, cr5-7 Nonvolatile
-lr Nonvolatile
-=========== ============= ========================================
-
---- For the scv 0 instruction, differences with the ELF ABI ---
-=========== ============= ========================================
-r0 Volatile (System call number.)
-r3 Volatile (Parameter 1, and return value.)
-r4-r8 Volatile (Parameters 2-6.)
-=========== ============= ========================================
++------------------------------------------------------------------------+
+| For the sc instruction, differences with the ELF ABI |
++--------------+--------------+------------------------------------------+
+| r0 | Volatile | (System call number.) |
+| rr3 | Volatile | (Parameter 1, and return value.) |
+| rr4-r8 | Volatile | (Parameters 2-6.) |
+| rcr0 | Volatile | (cr0.SO is the return error condition.) |
+| rcr1, cr5-7 | Nonvolatile | |
+| rlr | Nonvolatile | |
++--------------+--------------+------------------------------------------+
+| For the scv 0 instruction, differences with the ELF ABI |
++--------------+--------------+------------------------------------------+
+| r0 | Volatile | (System call number.) |
+| r3 | Volatile | (Parameter 1, and return value.) |
+| r4-r8 | Volatile | (Parameters 2-6.) |
++--------------+--------------+------------------------------------------+
All floating point and vector data registers as well as control and status
registers are nonvolatile.