Xtensa GPR and ABI
来自Jack's Lab
（版本间的差异）
(→Windowed Register ABI) |
(→Argument passing) |
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| 第18行： | 第18行： | ||
<pre> | <pre> | ||
| − | + | Return Addr Stack Ptr arg0, arg1, arg2, arg3, arg4, arg5 | |
----------- --------- ---------------------------------- | ----------- --------- ---------------------------------- | ||
a0 a1 a2, a3, a4, a5, a6, a7 | a0 a1 a2, a3, a4, a5, a6, a7 | ||
2016年11月16日 (三) 11:28的版本
目录 |
1 Overview
Two different ABI:
- Windowed register ABI, works with the Windowed Register Option (ESP32 use this ABI by default)
- CALL0 ABI, used with any Xtensa processor (worse performance)
Instruction CALL0 is for the CALL0 ABI
Instruction CALL4/CALL8/CALL12 is for the windowed register ABI
2 Windowed Register ABI
2.1 Argument passing
Return Addr Stack Ptr arg0, arg1, arg2, arg3, arg4, arg5
----------- --------- ----------------------------------
a0 a1 a2, a3, a4, a5, a6, a7
call4 a4 a5 a6, a7, a8, a9, a10, a11
call8 a8 a9 a10, a11, a12, a13, a14, a15
call12 a12 a13 a14, a15 --- --- --- ---
2.2 Return value
3 CALL0 ABI
3.1 Argument passing
3.2 Return value
