arm: thumb understanding++

userland/arch/arm/dump_regs.c

@@ -0,0 +1,16 @@
+/* Dump ARM registers that can be read in EL0 (and higher). */
+
+#include <stdio.h>
+#include <inttypes.h>
+
+int main(void) {
+    uint32_t cpsr;
+    uint32_t cpsr_m;
+    __asm__ ("mrs %0, cpsr" : "=r" (cpsr) : :);
+    printf("CPSR 0x%" PRIX32 "\n", cpsr);
+    /* https://github.com/cirosantilli/linux-kernel-module-cheat#arm-exception-levels */
+    cpsr_m = cpsr & 0xF;
+    printf("CPSR.M 0x%" PRIX32 "\n", cpsr_m);
+
+    return 0;
+}