From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6nke=20Holz?= <sholz8530@gmail.com>
Date: Thu, 8 May 2025 13:20:05 +0200
Subject: [PATCH] RISC-V: Implement __init_riscv_feature_bits for Minerva

The Minerva dynamic linker provides a magic function
"__get_riscv_feature_bits" that populates __riscv_feature_bits
and __riscv_cpu_model.
---
 libgcc/config/riscv/feature_bits.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/libgcc/config/riscv/feature_bits.c b/libgcc/config/riscv/feature_bits.c
index 157bcdcad69a939037f6faca3a90c2598dd61f89..8b3f45ffda99f3931ca86b0623283cf029918489 100644
--- a/libgcc/config/riscv/feature_bits.c
+++ b/libgcc/config/riscv/feature_bits.c
@@ -145,7 +145,7 @@ struct {
 
 #define SET_EXT(EXT) features[EXT##_GROUPID] |= EXT##_BITMASK
 
-#ifdef __linux
+#if defined(__linux)
 
 #define __NR_riscv_hwprobe 258
 #define RISCV_HWPROBE_KEY_MVENDORID 0
@@ -376,6 +376,27 @@ static void __init_riscv_features_bits_linux ()
 
   __riscv_feature_bits.length = RISCV_FEATURE_BITS_LENGTH;
 }
+
+#elif defined(__minerva__)
+
+extern void __get_riscv_feature_bits(void*, void*) __attribute__((weak));
+
+static void __init_riscv_features_bits_minerva ()
+{
+  if (__get_riscv_feature_bits)
+    {
+      __riscv_feature_bits.length = RISCV_FEATURE_BITS_LENGTH;
+      __get_riscv_feature_bits (&__riscv_feature_bits, &__riscv_cpu_model);
+    }
+  else
+    {
+      __riscv_feature_bits.length = 0;
+      __riscv_cpu_model.mvendorid = 0;
+      __riscv_cpu_model.marchid = 0;
+      __riscv_cpu_model.mimpid = 0;
+    }
+}
+
 #endif
 
 
@@ -388,8 +409,10 @@ __init_riscv_feature_bits ()
   if (__init)
     return;
 
-#ifdef __linux
+#if defined(__linux)
   __init_riscv_features_bits_linux ();
+#elif defined(__minerva__)
+  __init_riscv_features_bits_minerva ();
 #else
   /* Unsupported, just initialize that into all zeros.  */
   __riscv_feature_bits.length = 0;