如何将 AT&T 语法转换为 intel 语法？

Question

在 AT&T 语法中，您可以执行类似 asm("mov %%eax, %0 ":"=r" (a[0])); 但不在英特尔语法中。 我想将这个 AT&T 语法翻译为 intel 语法，它获取 cpu 品牌名称并打印它。

int a[10];
void brandString(int eaxValues)
{
    if (eaxValues == 1) {
    __asm__("mov $0x80000002 , %eax\n\t");
    }
    else if (eaxValues == 2) {
        __asm__("mov $0x80000003 , %eax\n\t");
    }
    else if (eaxValues == 3) {
        __asm__("mov $0x80000004 , %eax\n\t");
    }
    __asm__("cpuid\n\t");
    __asm__("mov %%eax, %0\n\t":"=r" (a[0]));
    __asm__("mov %%ebx, %0\n\t":"=r" (a[1]));
    __asm__("mov %%ecx, %0\n\t":"=r" (a[2]));
    __asm__("mov %%edx, %0\n\t":"=r" (a[3]));
    printf("%s", &a[0]);
}

void getCpuID()
{
    __asm__("xor %eax , %eax\n\t");
    __asm__("xor %ebx , %ebx\n\t");
    __asm__("xor %ecx , %ecx\n\t");
    __asm__("xor %edx , %edx\n\t");
    printf("Brand string is ");
    brandString(1);
    brandString(2);
    brandString(3);
    printf("\n");
}

int main(){
    getCpuID();
}

到目前为止，我已经做到了：

char a[10];
void brandString(int eaxValues)
{
    if (eaxValues == 1) {
        __asm {
            mov eax, 0x80000002
        }
    }
    else if (eaxValues == 2) {
        __asm {
            mov eax, 0x80000003
        }
    }
    else if (eaxValues == 3) {
        __asm {
            mov eax, 0x80000004
        }
    }
    
    __asm {
         cpuid
         mov    a[0], eax
         mov    a[1], ebx  
         mov    a[2], ecx  
         mov    a[3], edx 
    }
    
    printf("%s", &a[0]);
}


void getCpuID() {
     __asm {
            xor eax, eax
            xor ebx, ebx
            xor ecx, ecx
            xor edx, edx
        }
    printf("Brand string is ");
    brandString(1);
    brandString(2);
    brandString(3);
    printf("\n");
}

但显然你不能做 mov a[0], eax 所以我被卡住了，我不知道该怎么做。

Answer 1

            unsigned int regs[4];
            char brand[49] = {0};

            // Inline assembly to call CPUID with given eax value and store results in regs
            #define cpuid(eax_val, regs) \
            __asm__ __volatile__ ( \
            "cpuid" \
            : "=a" (regs[0]), "=b" (regs[1]), "=c" (regs[2]), "=d" (regs[3]) \
            : "a" (eax_val) \
            );

            // Call CPUID with 0x80000002, 0x80000003, and 0x80000004 and store the brand string
            cpuid(0x80000002, regs);
            memcpy(brand, regs, sizeof(regs));

            cpuid(0x80000003, regs);
            memcpy(brand + 16, regs, sizeof(regs));

            cpuid(0x80000004, regs);
            memcpy(brand + 32, regs, sizeof(regs));

            printf("  Brand string is: %s\n\n", brand);