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-rw-r--r--target/microblaze/cpu-param.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/target/microblaze/cpu-param.h b/target/microblaze/cpu-param.h
index 4abbc62d50..4d8297fa94 100644
--- a/target/microblaze/cpu-param.h
+++ b/target/microblaze/cpu-param.h
@@ -8,9 +8,24 @@
#ifndef MICROBLAZE_CPU_PARAM_H
#define MICROBLAZE_CPU_PARAM_H 1
+/*
+ * While system mode can address up to 64 bits of address space,
+ * this is done via the lea/sea instructions, which are system-only
+ * (as they also bypass the mmu).
+ *
+ * We can improve the user-only experience by only exposing 32 bits
+ * of address space.
+ */
+#ifdef CONFIG_USER_ONLY
+#define TARGET_LONG_BITS 32
+#define TARGET_PHYS_ADDR_SPACE_BITS 32
+#define TARGET_VIRT_ADDR_SPACE_BITS 32
+#else
#define TARGET_LONG_BITS 64
#define TARGET_PHYS_ADDR_SPACE_BITS 64
#define TARGET_VIRT_ADDR_SPACE_BITS 64
+#endif
+
/* FIXME: MB uses variable pages down to 1K but linux only uses 4k. */
#define TARGET_PAGE_BITS 12
#define NB_MMU_MODES 3