#include <exports.h> #ifndef GCC_VERSION #define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__) #endif /* GCC_VERSION */ #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_NIOS2) /* * r15 holds the pointer to the global_data, r8 is call-clobbered */ #define EXPORT_FUNC(x) \ asm volatile ( \ " .globl " #x "\n" \ #x ":\n" \ " movhi r8, %%hi(%0)\n" \ " ori r8, r0, %%lo(%0)\n" \ " add r8, r8, r15\n" \ " ldw r8, 0(r8)\n" \ " ldw r8, %1(r8)\n" \ " jmp r8\n" \ : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "r15"); #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"); #elif defined(CONFIG_MICROBLAZE) /* * r31 holds the pointer to the global_data. r5 is a call-clobbered. */ #define EXPORT_FUNC(x) \ asm volatile ( \ " .globl " #x "\n" \ #x ":\n" \ " lwi r5, r31, %0\n" \ " lwi r5, r5, %1\n" \ " bra r5\n" \ : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "r5"); #elif defined(CONFIG_BLACKFIN) /* * P5 holds the pointer to the global_data, P0 is a call-clobbered * register */ #define EXPORT_FUNC(x) \ asm volatile ( \ " .globl " #x "\n" \ #x ":\n" \ " P0 = [P5 + %0]\n" \ " P0 = [P0 + %1]\n" \ " JUMP (P0)\n" \ : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "P0"); #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) */ #if GCC_VERSION < 3004 static #endif /* GCC_VERSION */ void __attribute__((unused)) dummy(void) { #include <_exports.h> } extern unsigned long __bss_start, _end; void app_startup(char **argv) { unsigned long * cp = &__bss_start; /* Zero out BSS */ while (cp < &_end) { *cp++ = 0; } #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