2014-03-21 Sabrini Ni <sabrinanitw@gmail.com>
* nds32/crt0.S: Refine.
* nds32/crt1.S: Refine.
This commit is contained in:
Jeff Johnston
parent
5ff6903e69
commit
b899f01579
@ -1,3 +1,8 @@
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2014-03-21 Sabrini Ni <sabrinanitw@gmail.com>
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* nds32/crt0.S: Refine.
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* nds32/crt1.S: Refine.
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2014-03-21 Sabrini Ni <sabrinanitw@gmail.com>
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* nds32/crt0.S: Set argc=argv=env=0.
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@ -36,7 +36,6 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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##
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##==============================================================================
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##------------------------------------------------------------------------------
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## Vector table setup
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##------------------------------------------------------------------------------
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@ -53,53 +52,48 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.type _start, @function
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.align 2
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_start:
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.L_fp_gp_lp_init:
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/* Initialization for $fp, $gp, and $lp. The _SDA_BASE_ location
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.L_fp_gp_init:
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/* Initialization for $fp and $gp. The _SDA_BASE_ location
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stands for Small Data Access. */
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la $fp, _FP_BASE_
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la $gp, _SDA_BASE_
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movi $lp, #0
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.L_stack_init:
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/* Initialization for $sp and make sure it is 8-byte aligned. */
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la $sp, _stack
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#if __NDS32_ISA_V3__
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bitci $sp, $sp, #7
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#else
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movi $r0, #-8 /* Set $r0 as 0xFFFFFFF8. */
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and $sp, $sp, $r0
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#endif
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.L_bss_clear:
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/* Clear bss section. */
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la $r3, _end
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la $r0, _edata
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beq $r0, $r3, .L_call_main /* Branch if no bss. */
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sub $r1, $r3, $r0 /* Size to be clear. */
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/* Set $r2 as how many words to be clear.
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Set $r1 as how many bytes are less than a woard to be clear. */
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srli $r2, $r1, #2
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andi $r1, $r1, #3
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beqz $r3, .Lbyte_clear
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la $r4, #0x00000000
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/* Clear bss section.
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Equivalence C code for follow part:
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if (_end == _edata) goto .L_call_main
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unsinged int *ptr = _edata;
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while (ptr != _end)
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*ptr++ = 0
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$r0 = ptr/_edata
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$r1 = _end
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$r2 = 0
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*/
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la $r0, _edata
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la $r1, _end
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movi $r2, #0
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beq $r0, $r1, .L_call_main /* Branch if no bss. */
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.Lword_clear:
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swi.bi $r4, [$r0], #4
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addi $r2, $r2, #-1
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bnez $r2, .Lword_clear /* Loop again ? */
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beqz $r1, .Lend_bss
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.Lbyte_clear:
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sbi.bi $r4, [$r0], #1
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addi $r1, $r1, #-1
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bnez $r1, .Lbyte_clear
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.Lend_bss:
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swi.bi $r2, [$r0], #4
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bne $r0, $r1, .Lword_clear
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.L_call_main:
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/* Prepare argc/argv/env for main function.
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Since there is no operating system so far,
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we set $r0, $r1, and $r2 to be zero. */
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we set $r0, $r1, and $r2 to be zero.
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Note: $r2 already set to zero in line 84. */
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movi $r0, 0
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movi $r1, 0
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movi $r2, 0
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/* Call 'main'. */
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la $r15, main
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jral $r15
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@ -118,6 +112,6 @@ _start:
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.L_forever_loop:
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/* Should never return here. */
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b .L_forever_loop
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b .L_forever_loop
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.size _start, .-_start
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@ -36,7 +36,6 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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##
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##==============================================================================
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##------------------------------------------------------------------------------
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## Vector table setup
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##------------------------------------------------------------------------------
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@ -53,45 +52,40 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.type _start, @function
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.align 2
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_start:
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.L_fp_gp_lp_init:
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/* Initialization for $fp, $gp, and $lp. The _SDA_BASE_ location
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.L_fp_gp_init:
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/* Initialization for $fp and $gp. The _SDA_BASE_ location
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stands for Small Data Access. */
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la $fp, _FP_BASE_
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la $gp, _SDA_BASE_
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movi $lp, #0
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.L_stack_init:
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/* Initialization for $sp and make sure it is 8-byte aligned. */
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la $sp, _stack
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#if __NDS32_ISA_V3__
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bitci $sp, $sp, #7
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#else
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movi $r0, #-8 /* Set $r0 as 0xFFFFFFF8. */
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and $sp, $sp, $r0
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#endif
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.L_bss_clear:
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/* Clear bss section. */
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la $r3, _end
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la $r0, _edata
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beq $r0, $r3, .L_call_main /* Branch if no bss. */
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sub $r1, $r3, $r0 /* Size to be clear. */
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/* Set $r2 as how many words to be clear.
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Set $r1 as how many bytes are less than a woard to be clear. */
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srli $r2, $r1, #2
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andi $r1, $r1, #3
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beqz $r3, .Lbyte_clear
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la $r4, #0x00000000
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/* Clear bss section.
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Equivalence C code for follow part:
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if (_end == _edata) goto .L_call_main
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unsinged int *ptr = _edata;
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while (ptr != _end)
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*ptr++ = 0
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$r0 = ptr/_edata
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$r1 = _end
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$r2 = 0
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*/
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la $r0, _edata
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la $r1, _end
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beq $r0, $r1, .L_call_main /* Branch if no bss. */
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movi $r2, #0
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.Lword_clear:
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swi.bi $r4, [$r0], #4
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addi $r2, $r2, #-1
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bnez $r2, .Lword_clear /* Loop again ? */
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beqz $r1, .Lend_bss
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.Lbyte_clear:
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sbi.bi $r4, [$r0], #1
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addi $r1, $r1, #-1
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bnez $r1, .Lbyte_clear
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.Lend_bss:
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swi.bi $r2, [$r0], #4
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bne $r0, $r1, .Lword_clear
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.L_call_main:
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/* Call '_init' to invoke constructors. */
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@ -124,6 +118,6 @@ _start:
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.L_forever_loop:
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/* Should never return here. */
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b .L_forever_loop
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b .L_forever_loop
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.size _start, .-_start
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