diff options
Diffstat (limited to 'roms/u-boot/examples/standalone/stubs.c')
| -rw-r--r-- | roms/u-boot/examples/standalone/stubs.c | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/roms/u-boot/examples/standalone/stubs.c b/roms/u-boot/examples/standalone/stubs.c new file mode 100644 index 000000000..5fb460454 --- /dev/null +++ b/roms/u-boot/examples/standalone/stubs.c @@ -0,0 +1,299 @@ +#include <common.h> +#include <exports.h> +#include <linux/compiler.h> + +struct cmd_tbl; + +#define FO(x) offsetof(struct jt_funcs, x) + +#if defined(CONFIG_X86) +/* + * 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 struct jt_funcs *jt; +gd_t *global_data; + +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .globl " #x "\n" \ +#x ":\n" \ +" movl %0, %%eax\n" \ +" movl jt, %%ecx\n" \ +" jmp *(%%ecx, %%eax)\n" \ + : : "i"(FO(x)) : "eax", "ecx"); +#elif defined(CONFIG_PPC) +/* + * r2 holds the pointer to the global_data, r11 is a call-clobbered + * register + */ +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .globl " #x "\n" \ +#x ":\n" \ +" lwz %%r11, %0(%%r2)\n" \ +" lwz %%r11, %1(%%r11)\n" \ +" mtctr %%r11\n" \ +" bctr\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r11"); +#elif defined(CONFIG_ARM) +#ifdef CONFIG_ARM64 +/* + * x18 holds the pointer to the global_data, x9 is a call-clobbered + * register + */ +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .globl " #x "\n" \ +#x ":\n" \ +" ldr x9, [x18, %0]\n" \ +" ldr x9, [x9, %1]\n" \ +" br x9\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "x9"); +#else +/* + * r9 holds the pointer to the global_data, ip is a call-clobbered + * register + */ +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .globl " #x "\n" \ +#x ":\n" \ +" ldr ip, [r9, %0]\n" \ +" ldr pc, [ip, %1]\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "ip"); +#endif +#elif defined(CONFIG_MIPS) +#ifdef CONFIG_CPU_MIPS64 +/* + * 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(f, a, x, ...) \ + asm volatile ( \ +" .globl " #x "\n" \ +#x ":\n" \ +" ld $25, %0($26)\n" \ +" ld $25, %1($25)\n" \ +" jr $25\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9"); +#else +/* + * 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(f, a, 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"(FO(x)) : "t9"); +#endif +#elif defined(CONFIG_NIOS2) +/* + * gp holds the pointer to the global_data, r8 is call-clobbered + */ +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .globl " #x "\n" \ +#x ":\n" \ +" movhi r8, %%hi(%0)\n" \ +" ori r8, r0, %%lo(%0)\n" \ +" add r8, r8, gp\n" \ +" ldw r8, 0(r8)\n" \ +" ldw r8, %1(r8)\n" \ +" jmp r8\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "gp"); +#elif defined(CONFIG_M68K) +/* + * d7 holds the pointer to the global_data, a0 is a call-clobbered + * register + */ +#define EXPORT_FUNC(f, a, 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"(FO(x)) : "a0"); +#elif defined(CONFIG_MICROBLAZE) +/* + * r31 holds the pointer to the global_data. r5 is a call-clobbered. + */ +#define EXPORT_FUNC(f, a, 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"(FO(x)) : "r5"); +#elif defined(CONFIG_SH) +/* + * r13 holds the pointer to the global_data. r1 is a call clobbered. + */ +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ + " .align 2\n" \ + " .globl " #x "\n" \ + #x ":\n" \ + " mov r13, r1\n" \ + " add %0, r1\n" \ + " mov.l @r1, r2\n" \ + " add %1, r2\n" \ + " mov.l @r2, r1\n" \ + " jmp @r1\n" \ + " nop\n" \ + " nop\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r1", "r2"); +#elif defined(CONFIG_NDS32) +/* + * r16 holds the pointer to the global_data. gp is call clobbered. + * not support reduced register (16 GPR). + */ +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .globl " #x "\n" \ +#x ":\n" \ +" lwi $r16, [$gp + (%0)]\n" \ +" lwi $r16, [$r16 + (%1)]\n" \ +" jr $r16\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "$r16"); +#elif defined(CONFIG_RISCV) +/* + * gp holds the pointer to the global_data. t0 is call clobbered. + */ +#ifdef CONFIG_ARCH_RV64I +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .globl " #x "\n" \ +#x ":\n" \ +" ld t0, %0(gp)\n" \ +" ld t0, %1(t0)\n" \ +" jr t0\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t0"); +#else +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .globl " #x "\n" \ +#x ":\n" \ +" lw t0, %0(gp)\n" \ +" lw t0, %1(t0)\n" \ +" jr t0\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t0"); +#endif +#elif defined(CONFIG_ARC) +/* + * r25 holds the pointer to the global_data. r10 is call clobbered. + */ +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile( \ +" .align 4\n" \ +" .globl " #x "\n" \ +#x ":\n" \ +" ld r10, [r25, %0]\n" \ +" ld r10, [r10, %1]\n" \ +" j [r10]\n" \ + : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r10"); +#elif defined(CONFIG_XTENSA) +/* + * Global data ptr is in global_data, jump table ptr is in jt. + * Windowed ABI: Jump just past 'entry' in target and adjust stack frame + * (extract stack frame size from target 'entry' instruction). + */ + +static void **jt; + +#if defined(__XTENSA_CALL0_ABI__) +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .extern jt\n" \ +" .globl " #x "\n" \ +" .align 4\n" \ +#x ":\n" \ +" l32i a8, %0, 0\n" \ +" l32i a8, a8, %1\n" \ +" jx a8\n" \ + : : "r"(jt), "i" (FO(x)) : "a8"); +#elif defined(__XTENSA_WINDOWED_ABI__) +#if XCHAL_HAVE_BE +# define SFT "8" +#else +# define SFT "12" +#endif +#define EXPORT_FUNC(f, a, x, ...) \ + asm volatile ( \ +" .extern jt\n" \ +" .globl " #x "\n" \ +" .align 4\n" \ +#x ":\n" \ +" entry sp, 16\n" \ +" l32i a8, %0, 0\n" \ +" l32i a8, a8, %1\n" \ +" l32i a9, a8, 0\n" \ +" extui a9, a9, " SFT ", 12\n" \ +" subx8 a9, a9, sp\n" \ +" movi a10, 16\n" \ +" sub a9, a10, a9\n" \ +" movsp sp, a9\n" \ +" addi a8, a8, 3\n" \ +" jx a8\n" \ + : : "r"(jt), "i" (FO(x)) : "a8", "a9", "a10"); +#else +#error Unsupported Xtensa ABI +#endif +#else +/*" addi $sp, $sp, -24\n" \ +" br $r16\n" \*/ + +#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 < 30400 +static +#endif /* GCC_VERSION */ +void __attribute__((unused)) dummy(void) +{ +#include <_exports.h> +} + +#include <asm/sections.h> + +void app_startup(char * const *argv) +{ + char *cp = __bss_start; + + /* Zero out BSS */ + while (cp < _end) + *cp++ = 0; + +#if defined(CONFIG_X86) + /* 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 |