[MIPS] Implementation of sel_ldr for MIPS architecture.

src/trusted/service_runtime/arch/mips/nacl_text_pad_test.S

+/*
+ * Copyright 2012 The Native Client Authors.  All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can
+ * be found in the LICENSE file.
+ */
+
+#include "native_client/src/trusted/service_runtime/include/bits/nacl_syscalls.h"
+#include "native_client/src/trusted/service_runtime/nacl_config.h"
+
+#define STORE_MASK $t7
+#define JUMP_MASK  $t6
+#define NACL_HALT  0x00000008  /*opcode for "jr $zero", Mips nacl halt*/
+
+        /*
+         * Code to test various address layout boundary conditions.
+         * This is a translation from the x86-{32,64} code, and is
+         * not intended to be super efficent, just good enough to
+         * print out the values that are designed, while maintaining
+         * strict control over the address space layout.
+         */
+
+        .text
+        .set noreorder
+start_of_text:
+
+        /*
+         * write_num_16.  Write an unsigned value in hex.
+         * a0 is descriptor number, a1 is unsigned value to write.
+         */
+        .p2align 4
+write_num_16:
+        addu  $sp, $sp, -40
+        and   $sp, $sp, STORE_MASK
+        sw    $ra, 36($sp)
+        addu  $a3, $sp, 32
+
+        move  $a2, $0
+do_digit_16:
+        addu  $a3, $a3, -1
+        addu  $a2, $a2, 1
+        and   $t0, $a1, 0xf
+
+        addu  $t0, $t0, '0'
+        addiu $t1, $t0, -57                /* 57 is ASCI value for '9'. */
+        blez  $t1, do_digit_not_upper
+        nop                                /* instructions in delay slot are
+                                            * deliberately indented */
+
+        addu  $t0, $t0, ('a'-'0'-10)
+do_digit_not_upper:
+        and   $a3, $a3, STORE_MASK
+        sb    $t0, 0($a3)
+        srl   $a1, $a1, 4
+
+        bne   $a1, $0, do_digit_16
+        nop
+        move  $a1, $a3
+        lui   $t9, %hi(NACL_SYSCALL_ADDR(NACL_sys_write))
+
+        addiu $t9, $t9, %lo(NACL_SYSCALL_ADDR(NACL_sys_write))
+        and   $t9, $t9, JUMP_MASK
+        jalr  $t9
+        nop
+
+        lw    $ra, 36($sp)
+        addu  $sp, $sp, 40
+        and   $sp, $sp, STORE_MASK
+        nop
+
+        and   $ra,$ra,JUMP_MASK
+        jr    $ra
+        nop
+        nop
+
+        .p2align 4
+        /*
+         * a0 is descriptor number, a1 is character to write
+         */
+write_char:
+        addu  $sp, $sp, -40
+        and   $sp, $sp, STORE_MASK
+        sw    $ra, 36($sp)
+        nop
+
+        and   $sp, $sp, STORE_MASK
+        sb    $a1, 16($sp)
+        addu  $a1, $sp, 16
+        addu  $a2, $zero, 1
+
+        lui   $t9, %hi(NACL_SYSCALL_ADDR(NACL_sys_write))
+        addiu $t9, $t9, %lo(NACL_SYSCALL_ADDR(NACL_sys_write))
+        nop
+        nop
+
+        nop
+        and   $t9, $t9, JUMP_MASK
+        jalr  $t9
+        nop
+
+        lw    $ra, 36($sp)
+        addu  $sp, $sp, 40
+        and   $sp, $sp, STORE_MASK
+        nop
+
+        and   $ra, $ra, JUMP_MASK
+        jr    $ra
+        nop
+        nop
+
+        .p2align 4
+        .globl _start
+_start:
+        /* basic I/O test */
+        addu  $sp, $sp, -16
+        and   $sp, $sp, STORE_MASK
+        addu  $a0, $zero, 1
+        lui   $a1, 0xdead
+
+        nop
+        ori   $a1, $a1, 0xbeef            /* branch delay slot */
+        jal   write_num_16
+        nop
+
+        addu  $a0, $zero, 1
+        addu  $a1, $zero, '\n'
+        jal   write_char
+        nop
+
+        lui   $a1, %hi(end_of_text)
+        addiu $a1, $a1, %lo(end_of_text)
+        jal   write_num_16
+        addu  $a0, $zero, 1
+
+        addu  $a0, $zero, 1
+        addu  $a1, $zero, '\n'
+        jal   write_char
+        nop
+
+        addu  $a0, $zero, 0
+        lui   $t9, %hi(NACL_SYSCALL_ADDR(NACL_sys_sysbrk))
+        addiu $t9, $t9, %lo(NACL_SYSCALL_ADDR(NACL_sys_sysbrk))
+        nop
+
+        nop
+        and   $t9, $t9, JUMP_MASK
+        jalr  $t9
+        nop
+
+        move  $s0, $v0                     /* save a copy of break addr */
+        move  $a1, $v0
+        jal   write_num_16
+        addu  $a0, $zero, 1
+
+        addu  $a0, $zero, 1
+        addu  $a1, $zero, '\n'
+        jal   write_char
+        nop
+
+        addu  $t5, $zero, 0                /* t5 holds eventual exit status */
+        lui   $a1, %hi(EXPECTED_BREAK)
+        addiu $a1, $a1, %lo(EXPECTED_BREAK)
+        addu  $a0, $zero, 1
+
+        sub   $t0, $a1, $s0
+        movn  $t5, $a0, $t0
+        jal   write_num_16
+        nop
+
+        addu  $a0, $zero, 1
+        addu  $a1, $zero, '\n'
+        jal   write_char
+        nop
+
+#if EXPECTED_RODATA != 0
+        addu  $a2, $zero, 12
+        lui   $a1, %hi(ro_str)
+        addiu $a1, $a1, %lo(ro_str)
+        addu  $a0, $zero, 1
+
+        lui   $t9, %hi(NACL_SYSCALL_ADDR(NACL_sys_write))
+        addiu $t9, $t9, %lo(NACL_SYSCALL_ADDR(NACL_sys_write))
+        nop
+        nop
+
+        nop
+        and   $t9, $t9, JUMP_MASK
+        jalr  $t9
+        nop
+
+        lui   $a1, %hi(ro_str)
+        addiu $a1, $a1, %lo(ro_str)
+        addu  $a0, $zero, 1
+        nop
+
+        nop
+        nop
+        jal   write_num_16
+        nop
+
+        addu  $a0, $zero, 1
+        addu  $a1, $zero, '\n'
+        jal   write_char
+        nop
+
+        lui   $a1, %hi(EXPECTED_RODATA)
+        addiu $a1, $a1, %lo(EXPECTED_RODATA)
+        lui   $a2, %hi(ro_str)
+        addiu $a2, $a2, %lo(ro_str)
+
+        addu  $a0, $zero, 1
+        sub   $t0, $a1, $a2
+        movn  $s0, $a0, $t0
+        nop
+
+        nop
+        nop
+        jal write_num_16
+        nop
+
+        addu  $a0, $zero, 1
+        addu  $a1, $zero, '\n'
+        jal   write_char
+        nop
+#endif
+
+        lui   $t9, %hi(NACL_SYSCALL_ADDR(NACL_sys_exit))
+        addiu $t9, $t9, %lo(NACL_SYSCALL_ADDR(NACL_sys_exit))
+        addu  $a0, $zero, $s0
+        nop
+
+        nop
+        and   $t9, $t9, JUMP_MASK
+        jalr  $t9
+        nop
+
+#if defined(PNACL_AS)
+/* NOTE: unlike x86 the alignment directive on Mips takes
+   the logarithm of the alignment */
+#define POW2_BIGGER_THAN_DOT 14
+        .align32 POW2_BIGGER_THAN_DOT, NACL_HALT
+        .fill (TEXT_EXTEND - (1 << POW2_BIGGER_THAN_DOT))/4, 4, NACL_HALT
+#else
+        .fill (TEXT_EXTEND - (. - start_of_text))/4, 4, NACL_HALT
+#endif
+
+end_of_text:
+
+#if EXPECTED_RODATA != 0
+        .section .rodata
+ro_str: .ascii "Hello world\n"
+#endif
+