Honored Contributor
Honored ContributorThat print debug_print i have put it for debug purpose.
This is the code which executes before starting the linux /* * linux/arch/nios2/boot/compressed/head.S * * This code can be loaded anywhere, eg FLASH ROM as reset vector, * as long as output does not overlap it. */ # include <asm/asm-offsets.h> # include <asm/asm-macros.h> .text .set noat .global _start _start: wrctl status, r0 /* disable interrupt */ /* invalidate all instruction cache */ movia r1, NIOS2_ICACHE_SIZE movui r2, NIOS2_ICACHE_LINE_SIZE 1: initi r1 sub r1, r1, r2 bgt r1, r0, 1b /* invalidate all data cache */ movia r1, NIOS2_DCACHE_SIZE movui r2, NIOS2_DCACHE_LINE_SIZE 1: initd 0(r1) sub r1, r1, r2 bgt r1, r0, 1b nextpc r1 /* Find out where we are */ chkadr: movia r2, chkadr beq r1, r2, finish_move /* We are running in correct address, done */ /* move code, r1: src, r2: dest, r3: last dest */ addi r1, r1, (_start - chkadr) /* Source */ movia r2, _start /* Destination */ movia r3, __bss_start /* End of copy */ 1: ldw r8, 0(r1) /* load a word from [r1] */ stw r8, 0(r2) /* stort a word to dest [r2] */ addi r1, r1, 4 /* inc the src addr */ addi r2, r2, 4 /* inc the dest addr */ blt r2, r3, 1b /* flush the data cache after moving */ movia r1, NIOS2_DCACHE_SIZE movui r2, NIOS2_DCACHE_LINE_SIZE 1: flushd 0(r1) sub r1, r1, r2 call debug_print bgt r1, r0, 1b movia r1, finish_move jmp r1 /* jmp to linked address */ finish_move: /* zero out the .bss segment (uninitialized common data) */ movia r2, __bss_start /* presume nothing is between */ movia r1, _end /* the .bss and _end. */ 1: stb r0, 0(r2) addi r2, r2, 1 bne r1, r2, 1b /* * set up the stack pointer, some where higher than _end. * The stack space must be greater than 32K for decompress. */ movia sp, 0x10000 add sp, sp, r2 /* save args passed from u-boot, maybe */ addi sp, sp, -16 stw r4, 0(sp) stw r5, 4(sp) stw r6, 8(sp) stw r7, 12(sp) /* decompress the kernel */ call decompress_kernel /* pass saved args to kernel */ ldw r4, 0(sp) ldw r5, 4(sp) ldw r6, 8(sp) ldw r7, 12(sp) /* flush all data cache after decompressing */ movia r1, NIOS2_DCACHE_SIZE movui r2, NIOS2_DCACHE_LINE_SIZE 1: flushd 0(r1) sub r1, r1, r2 call debug_print bgt r1, r0, 1b /* flush all instruction cache */ movia r1, NIOS2_ICACHE_SIZE movui r2, NIOS2_ICACHE_LINE_SIZE 1: flushi r1 sub r1, r1, r2 bgt r1, r0, 1b flushp /* jump to start real kernel */ movia r1, (LINUX_SDRAM_START | KERNEL_REGION_BASE_ASM) call debug_print jmp r1 data cache flush is happening in the subroutine chkadr and there its working fine , but in the subroutine finish_move the same thing flushing of data cache is going in an infinite loop. Pls help me out what could be the issue.
