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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 | #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"); #elif defined(CONFIG_MICROBLZE) /* * 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"); #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> } 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 |