rdtsc register order incorrect

[samek-h]

learn/content/courses/Ada_For_The_Embedded_C_Developer/chapters/04_Embedded.rst

Line 183 in 918ccf1

(Unsigned_32'Asm_Output ("=a", High),

In this example, the order of registers is in the rdtsc instruction is written as follows:

   Asm ("rdtsc",
        Outputs =>
          (Unsigned_32'Asm_Output ("=a", High),
           Unsigned_32'Asm_Output ("=d", Low)),
        Volatile => True);

But the rdtsc stores the 32-bit parts of the value the other way around - low into EAX, high into EDX.

From the intel Manual: "The EDX register is loaded with the high-order 32 bits of the MSR and the EAX register is loaded with the low-order 32 bits. "

For more details, refer to Intel® 64 and IA-32 Architectures Software Developer’s Manual, vol. 2B, chapter 4.3.