xtensa: add support for the xtensa processor architecture [1/2]

[u-boot.git] / examples / standalone / stubs.c

diff --git a/examples/standalone/stubs.c b/examples/standalone/stubs.c
index 0d62067e03be4cbf97e1cd8c38adf503f9120700..a8b7e14c049081278280b95325a2edefe58a16b0 100644 (file)
--- a/examples/standalone/stubs.c
+++ b/examples/standalone/stubs.c
@@ -240,6 +240,53 @@ gd_t *global_data;
 "      ld      r10, [r10, %1]\n" \
 "      j       [r10]\n" \
        : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r10");
+#elif defined(CONFIG_XTENSA)
+/*
+ * Global data ptr is in global_data, jump table ptr is in jt.
+ * Windowed ABI: Jump just past 'entry' in target and adjust stack frame
+ * (extract stack frame size from target 'entry' instruction).
+ */
+
+static void **jt;
+
+#if defined(__XTENSA_CALL0_ABI__)
+#define EXPORT_FUNC(f, a, x, ...)      \
+       asm volatile (                  \
+"      .extern jt\n"                   \
+"      .globl " #x "\n"                \
+"      .align 4\n"                     \
+#x ":\n"                               \
+"      l32i    a8, %0, 0\n"            \
+"      l32i    a8, a8, %1\n"           \
+"      jx      a8\n"                   \
+       : : "r"(jt), "i" (FO(x)) : "a8");
+#elif defined(__XTENSA_WINDOWED_ABI__)
+#if XCHAL_HAVE_BE
+# define SFT "8"
+#else
+# define SFT "12"
+#endif
+#define EXPORT_FUNC(f, a, x, ...)      \
+       asm volatile (                  \
+"      .extern jt\n"                   \
+"      .globl " #x "\n"                \
+"      .align 4\n"                     \
+#x ":\n"                               \
+"      entry   sp, 16\n"               \
+"      l32i    a8, %0, 0\n"            \
+"      l32i    a8, a8, %1\n"           \
+"      l32i    a9, a8, 0\n"            \
+"      extui   a9, a9, " SFT ", 12\n"  \
+"      subx8   a9, a9, sp\n"           \
+"      movi    a10, 16\n"              \
+"      sub     a9, a10, a9\n"          \
+"      movsp   sp, a9\n"               \
+"      addi    a8, a8, 3\n"            \
+"      jx      a8\n"                   \
+       : : "r"(jt), "i" (FO(x)) : "a8", "a9", "a10");
+#else
+#error Unsupported Xtensa ABI
+#endif
 #else
 /*"    addi    $sp, $sp, -24\n"        \
 "      br      $r16\n"                 \*/