1 #include <exports.h> 2 3 #ifndef GCC_VERSION 4 #define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__) 5 #endif /* GCC_VERSION */ 6 7 #if defined(CONFIG_I386) 8 /* 9 * x86 does not have a dedicated register to store the pointer to 10 * the global_data. Thus the jump table address is stored in a 11 * global variable, but such approach does not allow for execution 12 * from flash memory. The global_data address is passed as argv[-1] 13 * to the application program. 14 */ 15 static void **jt; 16 gd_t *global_data; 17 18 #define EXPORT_FUNC(x) \ 19 asm volatile ( \ 20 " .globl " #x "\n" \ 21 #x ":\n" \ 22 " movl %0, %%eax\n" \ 23 " movl jt, %%ecx\n" \ 24 " jmp *(%%ecx, %%eax)\n" \ 25 : : "i"(XF_ ## x * sizeof(void *)) : "eax", "ecx"); 26 #elif defined(CONFIG_PPC) 27 /* 28 * r2 holds the pointer to the global_data, r11 is a call-clobbered 29 * register 30 */ 31 #define EXPORT_FUNC(x) \ 32 asm volatile ( \ 33 " .globl " #x "\n" \ 34 #x ":\n" \ 35 " lwz %%r11, %0(%%r2)\n" \ 36 " lwz %%r11, %1(%%r11)\n" \ 37 " mtctr %%r11\n" \ 38 " bctr\n" \ 39 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "r11"); 40 #elif defined(CONFIG_ARM) 41 /* 42 * r8 holds the pointer to the global_data, ip is a call-clobbered 43 * register 44 */ 45 #define EXPORT_FUNC(x) \ 46 asm volatile ( \ 47 " .globl " #x "\n" \ 48 #x ":\n" \ 49 " ldr ip, [r8, %0]\n" \ 50 " ldr pc, [ip, %1]\n" \ 51 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "ip"); 52 #elif defined(CONFIG_MIPS) 53 /* 54 * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call- 55 * clobbered register that is also used to set gp ($26). Note that the 56 * jr instruction also executes the instruction immediately following 57 * it; however, GCC/mips generates an additional `nop' after each asm 58 * statement 59 */ 60 #define EXPORT_FUNC(x) \ 61 asm volatile ( \ 62 " .globl " #x "\n" \ 63 #x ":\n" \ 64 " lw $25, %0($26)\n" \ 65 " lw $25, %1($25)\n" \ 66 " jr $25\n" \ 67 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "t9"); 68 #elif defined(CONFIG_NIOS) 69 /* 70 * %g7 holds the pointer to the global_data. %g0 is call clobbered. 71 */ 72 #define EXPORT_FUNC(x) \ 73 asm volatile ( \ 74 " .globl " #x "\n" \ 75 #x ":\n" \ 76 " pfx %%hi(%0)\n" \ 77 " movi %%g0, %%lo(%0)\n" \ 78 " add %%g0, %%g7\n" \ 79 " ld %%g0, [%%g0]\n" \ 80 " pfx %1\n" \ 81 " ld %%g0, [%%g0]\n" \ 82 " jmp %%g0\n" \ 83 " nop \n" \ 84 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x) : "r0"); 85 #elif defined(CONFIG_NIOS2) 86 /* 87 * r15 holds the pointer to the global_data, r8 is call-clobbered 88 */ 89 #define EXPORT_FUNC(x) \ 90 asm volatile ( \ 91 " .globl " #x "\n" \ 92 #x ":\n" \ 93 " movhi r8, %%hi(%0)\n" \ 94 " ori r8, r0, %%lo(%0)\n" \ 95 " add r8, r8, r15\n" \ 96 " ldw r8, 0(r8)\n" \ 97 " ldw r8, %1(r8)\n" \ 98 " jmp r8\n" \ 99 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "r15"); 100 #elif defined(CONFIG_M68K) 101 /* 102 * d7 holds the pointer to the global_data, a0 is a call-clobbered 103 * register 104 */ 105 #define EXPORT_FUNC(x) \ 106 asm volatile ( \ 107 " .globl " #x "\n" \ 108 #x ":\n" \ 109 " move.l %%d7, %%a0\n" \ 110 " adda.l %0, %%a0\n" \ 111 " move.l (%%a0), %%a0\n" \ 112 " adda.l %1, %%a0\n" \ 113 " move.l (%%a0), %%a0\n" \ 114 " jmp (%%a0)\n" \ 115 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "a0"); 116 #elif defined(CONFIG_MICROBLAZE) 117 /* 118 * r31 holds the pointer to the global_data. r5 is a call-clobbered. 119 */ 120 #define EXPORT_FUNC(x) \ 121 asm volatile ( \ 122 " .globl " #x "\n" \ 123 #x ":\n" \ 124 " lwi r5, r31, %0\n" \ 125 " lwi r5, r5, %1\n" \ 126 " bra r5\n" \ 127 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "r5"); 128 #elif defined(CONFIG_BLACKFIN) 129 /* 130 * P5 holds the pointer to the global_data, P0 is a call-clobbered 131 * register 132 */ 133 #define EXPORT_FUNC(x) \ 134 asm volatile ( \ 135 " .globl _" #x "\n_" \ 136 #x ":\n" \ 137 " P0 = [P5 + %0]\n" \ 138 " P0 = [P0 + %1]\n" \ 139 " JUMP (P0)\n" \ 140 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "P0"); 141 #elif defined(CONFIG_AVR32) 142 /* 143 * r6 holds the pointer to the global_data. r8 is call clobbered. 144 */ 145 #define EXPORT_FUNC(x) \ 146 asm volatile( \ 147 " .globl\t" #x "\n" \ 148 #x ":\n" \ 149 " ld.w r8, r6[%0]\n" \ 150 " ld.w pc, r8[%1]\n" \ 151 : \ 152 : "i"(offsetof(gd_t, jt)), "i"(XF_ ##x) \ 153 : "r8"); 154 #elif defined(CONFIG_SH) 155 /* 156 * r13 holds the pointer to the global_data. r1 is a call clobbered. 157 */ 158 #define EXPORT_FUNC(x) \ 159 asm volatile ( \ 160 " .align 2\n" \ 161 " .globl " #x "\n" \ 162 #x ":\n" \ 163 " mov r13, r1\n" \ 164 " add %0, r1\n" \ 165 " mov.l @r1, r2\n" \ 166 " add %1, r2\n" \ 167 " mov.l @r2, r1\n" \ 168 " jmp @r1\n" \ 169 " nop\n" \ 170 " nop\n" \ 171 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x * sizeof(void *)) : "r1", "r2"); 172 #elif defined(CONFIG_SPARC) 173 /* 174 * g7 holds the pointer to the global_data. g1 is call clobbered. 175 */ 176 #define EXPORT_FUNC(x) \ 177 asm volatile( \ 178 " .globl\t" #x "\n" \ 179 #x ":\n" \ 180 " set %0, %%g1\n" \ 181 " or %%g1, %%g7, %%g1\n" \ 182 " ld [%%g1], %%g1\n" \ 183 " ld [%%g1 + %1], %%g1\n" \ 184 " call %%g1\n" \ 185 " nop\n" \ 186 : : "i"(offsetof(gd_t, jt)), "i"(XF_ ## x) : "g1" ); 187 188 #else 189 #error stubs definition missing for this architecture 190 #endif 191 192 /* This function is necessary to prevent the compiler from 193 * generating prologue/epilogue, preparing stack frame etc. 194 * The stub functions are special, they do not use the stack 195 * frame passed to them, but pass it intact to the actual 196 * implementation. On the other hand, asm() statements with 197 * arguments can be used only inside the functions (gcc limitation) 198 */ 199 #if GCC_VERSION < 3004 200 static 201 #endif /* GCC_VERSION */ 202 void __attribute__((unused)) dummy(void) 203 { 204 #include <_exports.h> 205 } 206 207 extern unsigned long __bss_start, _end; 208 209 void app_startup(char **argv) 210 { 211 unsigned char * cp = (unsigned char *) &__bss_start; 212 213 /* Zero out BSS */ 214 while (cp < (unsigned char *)&_end) { 215 *cp++ = 0; 216 } 217 218 #if defined(CONFIG_I386) 219 /* x86 does not have a dedicated register for passing global_data */ 220 global_data = (gd_t *)argv[-1]; 221 jt = global_data->jt; 222 #endif 223 } 224 225 #undef EXPORT_FUNC 226