lib: Don't return any invalid error from SBI ecall
We should only return valid error codes from SBI ecalls as
defined by the RISC-V SBI spec.
To achieve this:
1. We use SBI_Exxxx defines for OpenSBI internal errors with
error values starting from -1000
2. We use SBI_ERR_xxxx defines for errors defined by SBI spec
3. We map some of the SBI_Exxxx defines to SBI_ERR_xxxx defines
which are semantically same
4. We throw a error print and force return error code to
SBI_ERR_FAILED in sbi_ecall_handler() if we see an invalid
error code being returned to S-mode
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>