Palmer, Anup,
On 4/22/24 10:58, Clément Léger wrote:
The current semihost exception number (16) is a reserved number (range
[16-17]). The upcoming double trap specification uses that number for
the double trap exception. Since the privileged spec (Table 22) defines
ranges for custom uses change the semihosting exception number to 63
which belongs to the range [48-63] in order to avoid any future
collisions with reserved exception.
I didn't find any reference to a number for the SEMIHOST exception here:
https://github.com/riscv-non-isa/riscv-semihosting
Do we have any potential candidates? I would like to avoid, if possible, setting
RISCV_EXCP_SEMIHOST to 63 as a band-aid just to replace it later on by the real
value.
Thanks,
Daniel
Signed-off-by: Clément Léger <cle...@rivosinc.com>
---
target/riscv/cpu_bits.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index fc2068ee4d..74318a925c 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -670,11 +670,11 @@ typedef enum RISCVException {
RISCV_EXCP_INST_PAGE_FAULT = 0xc, /* since: priv-1.10.0 */
RISCV_EXCP_LOAD_PAGE_FAULT = 0xd, /* since: priv-1.10.0 */
RISCV_EXCP_STORE_PAGE_FAULT = 0xf, /* since: priv-1.10.0 */
- RISCV_EXCP_SEMIHOST = 0x10,
RISCV_EXCP_INST_GUEST_PAGE_FAULT = 0x14,
RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT = 0x15,
RISCV_EXCP_VIRT_INSTRUCTION_FAULT = 0x16,
RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT = 0x17,
+ RISCV_EXCP_SEMIHOST = 0x3f,
} RISCVException;
#define RISCV_EXCP_INT_FLAG 0x80000000
