| #include <exports.h> |
| |
| #if defined(CONFIG_I386) |
| /* |
| * x86 does not have a dedicated register to store the pointer to |
| * the global_data. Thus the jump table address is stored in a |
| * global variable, but such approach does not allow for execution |
| * from flash memory. The global_data address is passed as argv[-1] |
| * to the application program. |
| */ |
| static void **jt; |
| gd_t *global_data; |
| |
| #define EXPORT_FUNC(x) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " movl %0, %%eax\n" \ |
| " movl jt, %%ecx\n" \ |
| " jmp *(%%ecx, %%eax)\n" \ |
| : : "i"(XF_ ## x * sizeof(void *)) : "eax", "ecx"); |
| #elif defined(CONFIG_PPC) |
| /* |
| * r29 holds the pointer to the global_data, r11 is a call-clobbered |
| * register |
| */ |
| #define EXPORT_FUNC(x) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " lwz %%r11, %0(%%r29)\n" \ |
| " lwz %%r11, %1(%%r11)\n" \ |
| " mtctr %%r11\n" \ |
| " bctr\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "r11"); |
| #elif defined(CONFIG_ARM) |
| /* |
| * r8 holds the pointer to the global_data, ip is a call-clobbered |
| * register |
| */ |
| #define EXPORT_FUNC(x) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " ldr ip, [r8, %0]\n" \ |
| " ldr pc, [ip, %1]\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "ip"); |
| #elif defined(CONFIG_MIPS) |
| /* |
| * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call- |
| * clobbered register that is also used to set gp ($26). Note that the |
| * jr instruction also executes the instruction immediately following |
| * it; however, GCC/mips generates an additional `nop' after each asm |
| * statement |
| */ |
| #define EXPORT_FUNC(x) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " lw $25, %0($26)\n" \ |
| " lw $25, %1($25)\n" \ |
| " jr $25\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "t9"); |
| #elif defined(CONFIG_NIOS) |
| /* |
| * %g7 holds the pointer to the global_data. %g0 is call clobbered. |
| */ |
| #define EXPORT_FUNC(x) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " pfx %%hi(%0)\n" \ |
| " movi %%g0, %%lo(%0)\n" \ |
| " add %%g0, %%g7\n" \ |
| " ld %%g0, [%%g0]\n" \ |
| " pfx %1\n" \ |
| " ld %%g0, [%%g0]\n" \ |
| " jmp %%g0\n" \ |
| " nop \n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x) : "r0"); |
| #elif defined(CONFIG_M68K) |
| /* |
| * d7 holds the pointer to the global_data, a0 is a call-clobbered |
| * register |
| */ |
| #define EXPORT_FUNC(x) \ |
| asm volatile ( \ |
| " .globl " #x "\n" \ |
| #x ":\n" \ |
| " move.l %%d7, %%a0\n" \ |
| " adda.l %0, %%a0\n" \ |
| " move.l (%%a0), %%a0\n" \ |
| " adda.l %1, %%a0\n" \ |
| " move.l (%%a0), %%a0\n" \ |
| " jmp (%%a0)\n" \ |
| : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "a0"); |
| #else |
| #error stubs definition missing for this architecture |
| #endif |
| |
| /* This function is necessary to prevent the compiler from |
| * generating prologue/epilogue, preparing stack frame etc. |
| * The stub functions are special, they do not use the stack |
| * frame passed to them, but pass it intact to the actual |
| * implementation. On the other hand, asm() statements with |
| * arguments can be used only inside the functions (gcc limitation) |
| */ |
| static void __attribute__((unused)) dummy(void) |
| { |
| #include <_exports.h> |
| } |
| |
| void app_startup(char **argv) |
| { |
| #if defined(CONFIG_I386) |
| /* x86 does not have a dedicated register for passing global_data */ |
| global_data = (gd_t *)argv[-1]; |
| jt = global_data->jt; |
| #endif |
| } |
| |
| #undef EXPORT_FUNC |