From 45231117b8686af3b896c9645a7b5b7b3b8e1cfc Mon Sep 17 00:00:00 2001 From: Evgeniy Naydanov Date: Tue, 25 Feb 2025 20:08:44 +0300 Subject: [PATCH] src/target/riscv: error out of the `examine()` in case `abits` is zero The spec requires `abits` to be no less then 7 ( [3.1. Debug Module Interface (DMI)]): > The DMI uses between 7 and 32 address bits Commit a450a7d4966a19c48b2543810f5b8370af6383e5 ("Fix data types around batch.{c,h}") introduced a check that issues a warning if `abits` is less then 7. The reason it's a warning and not an error -- on Spike `abits` is 6. However, if the examination is to proceed when `abits` is zero, an assert in `get_dmi_scan_length()` will trigger when attempting to communicate over DMI. Link: https://github.com/JanMatCodasip/riscv-openocd/blob/a450a7d4966a19c48b2543810f5b8370af6383e5/src/target/riscv/batch.c#L25 It's impossible to communicate over DMI with `abits == 0`, so an error is returned instead of a warning in this case. Change-Id: Ice4622adccfc8304b37bc678253cc19d8ac1457e Signed-off-by: Evgeniy Naydanov --- src/target/riscv/riscv-013.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/target/riscv/riscv-013.c b/src/target/riscv/riscv-013.c index 23c0aa62c..e81b1abc5 100644 --- a/src/target/riscv/riscv-013.c +++ b/src/target/riscv/riscv-013.c @@ -1956,6 +1956,11 @@ static int examine(struct target *target) return ERROR_FAIL; } + if (info->abits == 0) { + LOG_TARGET_ERROR(target, + "dtmcs.abits is zero. Check JTAG connectivity/board power"); + return ERROR_FAIL; + } if (info->abits < RISCV013_DTMCS_ABITS_MIN) { /* The requirement for minimum DMI address width of 7 bits is part of * the RISC-V Debug spec since Jan-20-2017 (commit 03df6ee7). However,