2 files changed, 30 insertions, 1 deletions

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 2d57da324562..d739d47fce56 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1039,7 +1039,7 @@ config DEBUG_UNCOMPRESS
         bool
         depends on ARCH_MULTIPLATFORM
         default y if DEBUG_LL && !DEBUG_OMAP2PLUS_UART && \
-                     !DEBUG_TEGRA_UART
+                     (!DEBUG_TEGRA_UART || !ZBOOT_ROM)
         help
           This option influences the normal decompressor output for
           multiplatform kernels.  Normally, multiplatform kernels disable
diff --git a/arch/arm/include/debug/tegra.S b/arch/arm/include/debug/tegra.S
index 883d7c22fd9d..be6a720dd183 100644
--- a/arch/arm/include/debug/tegra.S
+++ b/arch/arm/include/debug/tegra.S
@@ -221,3 +221,32 @@
 1002:
 #endif
                 .endm
+
+/*
+ * Storage for the state maintained by the macros above.
+ *
+ * In the kernel proper, this data is located in arch/arm/mach-tegra/common.c.
+ * That's because this header is included from multiple files, and we only
+ * want a single copy of the data. In particular, the UART probing code above
+ * assumes it's running using physical addresses. This is true when this file
+ * is included from head.o, but not when included from debug.o. So we need
+ * to share the probe results between the two copies, rather than having
+ * to re-run the probing again later.
+ *
+ * In the decompressor, we put the symbol/storage right here, since common.c
+ * isn't included in the decompressor build. This symbol gets put in .text
+ * even though it's really data, since .data is discarded from the
+ * decompressor. Luckily, .text is writeable in the decompressor, unless
+ * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
+ */
+#if defined(ZIMAGE)
+tegra_uart_config:
+        /* Debug UART initialization required */
+        .word 1
+        /* Debug UART physical address */
+        .word 0
+        /* Debug UART virtual address */
+        .word 0
+        /* Scratch space for debug macro */
+        .word 0
+#endif