/*
 * copy_c2_ram.S
 *
 *  Created on: Jan 12, 2011
 *  Author: MIPS TECHNOLOGIES, INC
 *  Copy code and data to ram then clear BSS
*/
/*
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*/
#include <regdef.h>
#include <boot.h>

#define s1_all_ones     s1   /* at Will hold 0xffffffff to simplify bit insertion of 1's. */
#define a0_temp_data    a0   /* a0 data to be moved */
#define a1_temp_addr    a1   /* from address */
#define a2_temp_dest    a2   /* to address */
#define a3_temp_mark    a3   /* ending address */


	.set	noreorder           # Don't allow the assembler to reorder instructions.
	.set	noat                # Don't allow the assembler to use r1(at) for synthetic instr.

/**************************************************************************************
**************************************************************************************/
LEAF(copy_c2_ram)

	li      s1_all_ones, 0xffffffff

/* RAMHACK: Link addr == load addr. No copy of code from ROM to RAM required.
    // Copy code and read-only/initialized data from FLASH to (uncached) RAM.
    la      a1_temp_addr, _zap1
    ins     a1_temp_addr, s1_all_ones, 29, 1
    la      a2_temp_dest, _ftext_ram
    ins     a2_temp_dest, s1_all_ones, 29, 1
    la      a3_temp_mark, _edata_ram
    ins     a3_temp_mark, s1_all_ones, 29, 1
    beq     a2_temp_dest, a3_temp_mark, zero_bss
    nop
next_ram_word:
    lw      a0_temp_data, 0(a1_temp_addr)
    sw      a0_temp_data, 0(a2_temp_dest)
    addiu   a2_temp_dest, 4
    bne     a3_temp_mark, a2_temp_dest, next_ram_word
    addiu   a1_temp_addr, 4
*/

// RAMHACK: Zero sbss in addition to bss.
zero_sbss:
    la      a1_temp_addr, _start_sbss
    ins     a1_temp_addr, s1_all_ones, 29, 1
    la      a3_temp_mark, _end_sbss
    ins     a3_temp_mark, s1_all_ones, 29, 1
    beq     a1_temp_addr, a3_temp_mark, zero_bss
    nop
next_sbss_word:
    sw      zero, 0(a1_temp_addr)
    addiu   a1_temp_addr, 4
    bne     a1_temp_addr, a3_temp_mark, next_sbss_word
    nop

zero_bss:
    la      a1_temp_addr, _start_bss
    ins     a1_temp_addr, s1_all_ones, 29, 1
    la      a3_temp_mark, _end_bss
    ins     a3_temp_mark, s1_all_ones, 29, 1
    beq     a1_temp_addr, a3_temp_mark, copy_c2_ram_done
    nop
next_bss_word:
    sw      zero, 0(a1_temp_addr)
    addiu   a1_temp_addr, 4
    bne     a1_temp_addr, a3_temp_mark, next_bss_word
    nop

copy_c2_ram_done:
    jr      ra
    nop
END(copy_c2_ram)