| 1 | .. comment SPDX-License-Identifier: CC-BY-SA-4.0 |
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| 2 | |
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| 3 | .. Copyright (C) 2018 embedded brains GmbH |
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| 4 | |
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| 5 | RISC-V Specific Information |
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| 6 | *************************** |
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| 7 | |
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| 8 | Calling Conventions |
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| 9 | =================== |
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| 10 | |
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| 11 | Please refer to the |
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| 12 | `RISC-V ELF psABI specification <https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md>`_. |
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| 13 | |
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| 14 | Multilibs |
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| 15 | ========= |
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| 16 | |
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| 17 | The GCC for RISC-V can generate code for several 32-bit and 64-bit ISA/ABI |
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| 18 | variants. The following multilibs are available: |
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| 19 | |
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| 20 | * ``.``: The default multilib ISA is RV32IMAFDC with ABI ILP32D. |
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| 21 | |
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| 22 | * ``rv32i/ilp32``: ISA RV32I with ABI ILP32. |
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| 23 | |
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| 24 | * ``rv32im/ilp32``: ISA RV32IM with ABI ILP32. |
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| 25 | |
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| 26 | * ``rv32imafd/ilp32d``: ISA RV32IMAFD with ABI ILP32D. |
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| 27 | |
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| 28 | * ``rv32iac/ilp32``: ISA RV32IAC with ABI ILP32. |
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| 29 | |
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| 30 | * ``rv32imac/ilp32``: ISA RV32IMAC with ABI ILP32. |
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| 31 | |
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| 32 | * ``rv32imafc/ilp32f``: ISA RV32IMAFC with ABI ILP32F. |
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| 33 | |
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| 34 | * ``rv64imafd/lp64d``: ISA RV64IMAFD with ABI LP64D and code model medlow. |
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| 35 | |
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| 36 | * ``rv64imafd/lp64d/medany``: ISA RV64IMAFD with ABI LP64D and code model medany. |
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| 37 | |
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| 38 | * ``rv64imac/lp64``: ISA RV64IMAC with ABI LP64 and code model medlow. |
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| 39 | |
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| 40 | * ``rv64imac/lp64/medany``: ISA RV64IMAC with ABI LP64 and code model medany. |
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| 41 | |
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| 42 | * ``rv64imafdc/lp64d``: ISA RV64IMAFDC with ABI LP64D and code model medlow. |
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| 43 | |
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| 44 | * ``rv64imafdc/lp64d/medany``: ISA RV64IMAFDC with ABI LP64D and code model medany. |
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| 45 | |
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| 46 | Interrupt Processing |
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| 47 | ==================== |
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| 48 | |
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| 49 | Interrupt exceptions are handled via the interrupt extensions API. All other |
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| 50 | exceptions end up in a fatal error (RTEMS_FATAL_SOURCE_EXCEPTION). |
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| 51 | |
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| 52 | Interrupt Levels |
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| 53 | ---------------- |
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| 54 | |
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| 55 | There are exactly two interrupt levels on RISC-V with respect to RTEMS. Level |
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| 56 | zero corresponds to machine interrupts enabled. Level one corresponds to |
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| 57 | machine interrupts disabled. |
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| 58 | |
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| 59 | Interrupt Stack |
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| 60 | --------------- |
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| 61 | |
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| 62 | The memory region for the interrupt stack is defined by the BSP. |
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| 63 | |
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| 64 | Default Fatal Error Processing |
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| 65 | ============================== |
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| 66 | |
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| 67 | The default fatal error is BSP-specific. |
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| 68 | |
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| 69 | Symmetric Multiprocessing |
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| 70 | ========================= |
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| 71 | |
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| 72 | SMP is supported. |
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| 73 | |
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| 74 | Thread-Local Storage |
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| 75 | ==================== |
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| 76 | |
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| 77 | Thread-local storage is supported. |
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![[RTEMS Logo]](/images/logo.png){kind=logo}
