diff options
Diffstat (limited to 'libgloss/nds32/crt1.S')
| -rw-r--r-- | libgloss/nds32/crt1.S | 96 |
1 files changed, 80 insertions, 16 deletions
diff --git a/libgloss/nds32/crt1.S b/libgloss/nds32/crt1.S index 2ff2eea..ec8b866 100644 --- a/libgloss/nds32/crt1.S +++ b/libgloss/nds32/crt1.S @@ -36,6 +36,8 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ## ##============================================================================== +#include "syscall_extra.h" + ##------------------------------------------------------------------------------ ## Vector table setup ##------------------------------------------------------------------------------ @@ -47,6 +49,11 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ##------------------------------------------------------------------------------ .section .text .weak _SDA_BASE_ + .weak _ITB_BASE_ + .weak _arg_init + .weak __pre_c_init + .weak __post_c_init + .weak _call_exit .global _start .type _start, @function .align 2 @@ -60,8 +67,22 @@ _start: determined by Linker. SDA stands for Small Data Access. */ la $gp, _SDA_BASE_ +#if __NDS32_EXT_EX9__ +.L_init_itb: + /* Initialization for Instruction Table Base (ITB). + The symbol _ITB_BASE_ is determined by Linker. + Set $ITB only if MSC_CFG.EIT (cr4.b'24) is set. */ + mfsr $r0, $MSC_CFG + srli $r0, $r0, 24 + andi $r0, $r0, 0x1 + beqz $r0, 1f /* Fall through ? */ + la $r0, _ITB_BASE_ + mtusr $r0, $ITB +1: +#endif + .L_init_sp: - /* Initialization for stack pointe. The symbol _stack is defined + /* Initialization for stack pointer. The symbol _stack is defined in linker script. Make sure $sp is 8-byte aligned. */ la $sp, _stack #if __NDS32_ISA_V3__ @@ -71,19 +92,29 @@ _start: and $sp, $sp, $r0 #endif -#if __NDS32_EX9_EXT__ -.L_init_itb: - /* Initialization for Instruction Table Base (ITB). - The symbol $_ITB_BASE_ is determined by Linker. - Set $ITB only if MSC_CFG.EIT (cr4.b'24) is set. */ - mfsr $r0, $MSC_CFG - srli $r0, $r0, 24 - andi $r0, $r0, 0x1 - beqz $r0, .L_zero_out_bss /* Fall through ? */ - la $r0, $_ITB_BASE_ - mtusr $r0, $ITB +#if __NDS32_EXT_FPU_SP__ || __NDS32_EXT_FPU_DP__ +.L_init_fpu: + /* Initialize FPU + Set FUCOP_CTL.CP0EN (fucpr.b'0). */ + mfsr $r0, $FUCOP_CTL + ori $r0, $r0, 0x1 + mtsr $r0, $FUCOP_CTL + dsb + /* According to [bugzilla #9425], set flush-to-zero mode. + That is, set $FPCSR.DNZ(b'12) = 1. */ + FMFCSR $r0 + ori $r0, $r0, 0x1000 + FMTCSR $r0 + dsb #endif +.L_pre_c_init: + ! call __pre_c_init if provided + ! sample __pre_c_init is in BSP + la $r15, __pre_c_init ! load address of __pre_c_init + beqz $r15, .L_zero_out_bss ! check existence of __pre_c_init + jral $r15 ! pre-c-runtime initialization + .L_zero_out_bss: /* Zero out the bss section. Equivalence C code for follow part: @@ -97,28 +128,61 @@ _start: */ la $r0, _edata la $r1, _end - beq $r0, $r1, .L_call_main /* Branch if no bss. */ movi $r2, #0 + beq $r0, $r1, .L_cpp_init /* Branch if no bss. */ .Lword_clear: swi.bi $r2, [$r0], #4 bne $r0, $r1, .Lword_clear -.L_call_main: +.L_cpp_init: /* Call '_init' to invoke constructors. */ jal _init /* Register '_fini' into atexit() to invoke destructors when exit() has been reached. */ la $r0, _fini jal atexit + +.L_post_c_init: + ! call __post_c_init if provided + ! no sample __post_c_init is provided + la $r15, __post_c_init ! load address of __post_c_init + beqz $r15, .L_arg_init ! check existence of __post_c_init + jral $r15 ! post-c-runtime initialization + +.L_arg_init: + ! argc/argv initialization if necessary + la $r7, _arg_init ! get address of _arg_init + beqz $r7, .L_clean_reg ! if there isn't _arg_init, go main + addi $sp, $sp, -512 ! allocate space for command line + ! and arguments + move $r6, $sp ! r6 = buffer addr of cmd line + move $r0, $r6 ! r0 = buffer addr of cmd line + syscall SYS_getcmdline ! get cmd line + move $r0, $r6 ! r0 = buffer addr of cmd line + addi $r1, $r6, 256 ! r1 = argv + jral $r7 ! init argc/argv + addi $r1, $r6, 256 ! r1 = argv + b .L_call_main + +.L_clean_reg: /* Prepare argc/argv/env for main function. Since there is no operating system so far, - we set $r0, $r1, and $r2 to be zero. */ + we set $r0, $r1, and $r2 to be zero. + Note: $r2 already set to zero in .L_zero_out_bss: code fragment. */ movi $r0, 0 movi $r1, 0 movi $r2, 0 + +.L_call_main: /* Call 'main'. */ bal main + /* Call _call_exit. */ + ! call _call_exit if necessary; default implementation is in crtexit.c + la $r15, _call_exit ! load address of _call_exit + beqz $r15, .L_terminate_program ! no _call_exit? go exit + jral $r15 ! _call_exit will never return + .L_terminate_program: /* There are two ways to terminate program: 1. User "syscall 0x1" directly. @@ -128,7 +192,7 @@ _start: Currently, we use option 2 as a solution to follow C99 5.1.2.2.3, but aware that general exit() will do some cleanup procedures which may result in large-memory-footprints. */ - + bal exit .L_forever_loop: |