x86 asm: mov

userland/arch/x86_64/mov.S

@@ -0,0 +1,37 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#userland-assembly */
+
+#include <lkmc.h>
+
+.data
+    myint: .long 0x12345678
+LKMC_PROLOGUE
+    /* Immediate and register. */
+    mov $0, %rax
+    mov $1, %rax
+    LKMC_ASSERT_EQ(%rax, $1)
+
+    /* Register and register. */
+    mov $0, %rax
+    mov $1, %rbx
+    mov %rbx, %rax
+    LKMC_ASSERT_EQ(%rax, $1)
+
+    /* Memory and register. */
+    mov myint, %rax
+    LKMC_ASSERT_EQ(%rax, $0x12345678)
+
+    /* Memory and immediate. */
+    movl $0x9ABCDEF0, myint
+    LKMC_ASSERT_EQ(myint, $0x9ABCDEF0)
+
+    /* Memory via pointer to address. */
+    /* eax = &myint */
+    mov $myint, %rax
+    movl $0x11112222, (%rax)
+    LKMC_ASSERT_EQ(myint, $0x11112222)
+
+    /* Possible to move on itself, seems like a NOP and way to clear 32 high bits in x86-64:
+     * http://stackoverflow.com/questions/11910501/why-did-gcc-generate-mov-eax-eax-and-what-does-it-mean
+     */
+    mov %rax, %rax
+LKMC_EPILOGUE