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Diffstat (limited to 'gitlab/issues_text/target_riscv/host_missing/accel_missing/904')
| -rw-r--r-- | gitlab/issues_text/target_riscv/host_missing/accel_missing/904 | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/gitlab/issues_text/target_riscv/host_missing/accel_missing/904 b/gitlab/issues_text/target_riscv/host_missing/accel_missing/904 new file mode 100644 index 000000000..440aaf90f --- /dev/null +++ b/gitlab/issues_text/target_riscv/host_missing/accel_missing/904 @@ -0,0 +1,16 @@ +RISC-V: Cannot set SEIP bit of mip csr register in M mode +Description of problem: + +Steps to reproduce: +1. run assembly instructions **in M mode**: +``` +not t0, x0 // set t0 to 0b11..11 +csrs mip, t0 // write mip with t0, mip registers are WARL(Write Any Values, Reads Legal Values) +csrr t1, mip // read value from mip to t1 +``` +2. GDB enters the command `display/z $t1` to see that the content of the t1 register is 0x466, which means that the SEIP bit of mip is not set. +3. According to page 47 of [riscv-privileged-20211203](https://github.com/riscv/riscv-isa-manual/releases/download/Priv-v1.12/riscv-privileged-20211203.pdf), `SEIP is writable in mip`. +4. According to page 81 of the same manual,`If implemented, SEIP is read-only in sip`. +5. However, the above code and results show that the SEIP bit of mip cannot be set by software **in M mode**. +Additional information: + |