| Line 113... |
Line 113... |
la $a0,msg1 # Print ramtop message...
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la $a0,msg1 # Print ramtop message...
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jal puts
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jal puts
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nop
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nop
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addi $a0,$t0,-4 # substract the +4 offset we added before
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addi $a0,$t0,-4 # substract the +4 offset we added before
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move $sp,$t0 # init SP at the top of RAM space
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move $sp,$t0 # init SP at the top of RAM space
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addi $sp,$sp,-4
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addi $sp,$sp,-16
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li $a1,8
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li $a1,8
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jal put_hex
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jal put_hex
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nop
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nop
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la $a0,crlf
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la $a0,crlf
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jal puts
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jal puts
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nop
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nop
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# FIXME now we should so some strong test on the RAM to see if it's wired
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# Test code execution from SRAM. We copy the test_exec_sram routine to
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# correctly, using the right timing, etc.
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# the base of the SRAM and then jal to it
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li $a1,64
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li $a0,XRAM_BASE
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la $a3,test_exec_sram
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copy_to_sram:
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lw $a2,0($a3)
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nop
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sw $a2,0($a0)
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addi $a1,$a1,-4
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addi $a3,$a3,4
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bnez $a1,copy_to_sram
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addi $a0,$a0,4
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.ifgt 0
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li $a0,0
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jal dump_hex
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ori $a1,$zero,16
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.endif
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li $a0,XRAM_BASE
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jalr $a0
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nop
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.ifgt 0
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# If all went well in the SRAM we'll have returned here
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# FIXME now we should so some strong test on the RAM to see if it's wired
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# correctly, using the right timing, etc.
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# Ok, now we know we have some RAM and stack space we can do some further
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# Ok, now we know we have some RAM and stack space we can do some further
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# testing.
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# testing.
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# dump the first few words of FLASH
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# dump the first few words of FLASH
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la $a0,msg2
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la $a0,msg2
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jal puts
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jal puts
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nop
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nop
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# FIXME flash base address is hardcoded
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# FIXME flash base address is hardcoded
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li $a0,0xb0000000
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li $a0,0xb0000000
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jal put_hex
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jal put_hex
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ori $a1,$zero,8
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ori $a1,$zero,8
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la $a0,crlf
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la $a0,crlf
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jal puts
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jal puts
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nop
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nop
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la $a0,crlf
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la $a0,crlf
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jal puts
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jal puts
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nop
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nop
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li $a0,0xb0000000
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li $a0,0xb0000000
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jal dump_hex
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jal dump_hex
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ori $a1,$zero,24
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ori $a1,$zero,24
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.endif
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$DONE:
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j $DONE # ...and freeze here
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nop
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$DONE:
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test_exec_sram:
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j $DONE # ...and freeze here
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#jr $ra
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nop
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#nop
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sw $ra,0($sp)
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addi $sp,$sp,-4
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la $a0,msg3
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la $a1,puts
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jalr $a1
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nop
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lw $ra,4($sp)
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jr $ra
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addi $sp,$sp,4
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test_exec_sram_end:
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#---- Functions ----------------------------------------------------------------
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# void dump_hex(int *address, int len)
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#---- Functions ----------------------------------------------------------------
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dump_hex:
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move $t7,$a0
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# void dump_hex(int *address, int len)
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move $t8,$a1
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dump_hex:
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sw $ra,0($sp)
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move $t7,$a0
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addi $sp,$sp,-4
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move $t8,$a1
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sw $ra,0($sp)
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addi $sp,$sp,-4
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dump_hex_loop:
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dump_hex_loop:
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lw $a0,0($t7)
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lw $a0,0($t7)
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jal put_hex
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jal put_hex
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li $a1,8
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li $a1,8
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la $a0,space
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la $a0,space
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jal puts
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jal puts
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addi $t7,4
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addi $t7,4
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addi $t8,$t8,-1
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addi $t8,$t8,-1
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bnez $t8,dump_hex_loop
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bnez $t8,dump_hex_loop
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nop
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nop
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lw $ra,4($sp)
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lw $ra,4($sp)
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jr $ra
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jr $ra
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addi $sp,$sp,4
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addi $sp,$sp,4
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#--- Special functions that do not use any RAM ---------------------------------
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#--- Special functions that do not use any RAM ---------------------------------
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# WARNING: Not for general use!
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# WARNING: Not for general use!
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# All parameters in $a0..$a4, stack unused. No attempt to comply with any ABI
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# All parameters in $a0..$a4, stack unused. No attempt to comply with any ABI
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# has been made.
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# has been made.
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# Since we can't use any RAM, register have been used liberally with no regard
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# Since we can't use any RAM, register have been used liberally with no regard
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# for intended usage -- have to share reg bank with calling function.
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# for intended usage -- have to share reg bank with calling function.
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# void puts(char *s) -- print zero-terminated string
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# void puts(char *s) -- print zero-terminated string
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puts:
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puts:
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la $a2,UART_BASE # UART base address
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la $a2,UART_BASE # UART base address
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puts_loop:
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puts_loop:
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lb $v0,0($a0)
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lb $v0,0($a0)
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beqz $v0,puts_end
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beqz $v0,puts_end
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addiu $a0,1
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addiu $a0,1
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puts_wait_tx_rdy:
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puts_wait_tx_rdy:
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lw $v1,UART_STATUS($a2)
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lw $v1,UART_STATUS($a2)
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andi $v1,$v1,0x02
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andi $v1,$v1,0x02
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beqz $v1,puts_wait_tx_rdy
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beqz $v1,puts_wait_tx_rdy
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nop
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nop
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sw $v0,UART_TX($a2)
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sw $v0,UART_TX($a2)
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b puts_loop
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b puts_loop
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nop
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nop
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puts_end:
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puts_end:
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jr $ra
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jr $ra
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nop
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nop
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# void put_hex(int n, int d) -- print integer as d-digit hex
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# void put_hex(int n, int d) -- print integer as d-digit hex
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put_hex:
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put_hex:
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la $a2,UART_BASE
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la $a2,UART_BASE
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la $a3,put_hex_table
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la $a3,put_hex_table
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addi $a1,-1
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addi $a1,-1
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add $a1,$a1,$a1
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add $a1,$a1,$a1
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add $a1,$a1,$a1
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add $a1,$a1,$a1
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put_hex_loop:
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put_hex_loop:
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srlv $v0,$a0,$a1
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srlv $v0,$a0,$a1
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andi $v0,$v0,0x0f
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andi $v0,$v0,0x0f
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addu $s2,$a3,$v0
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addu $s2,$a3,$v0
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lb $v0,0($s2)
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lb $v0,0($s2)
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put_hex_wait_tx_rdy:
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put_hex_wait_tx_rdy:
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lw $v1,UART_STATUS($a2)
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lw $v1,UART_STATUS($a2)
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andi $v1,$v1,0x02
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andi $v1,$v1,0x02
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beqz $v1,put_hex_wait_tx_rdy
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beqz $v1,put_hex_wait_tx_rdy
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nop
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nop
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sw $v0,UART_TX($a2)
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sw $v0,UART_TX($a2)
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bnez $a1,put_hex_loop
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bnez $a1,put_hex_loop
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addi $a1,-4
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addi $a1,-4
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jr $ra
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jr $ra
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nop
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nop
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#---- Constant data (note we keep it in the text section) ----------------------
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put_hex_table:
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#---- Constant data (note we keep it in the text section) ----------------------
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.ascii "0123456789abcdef"
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msg0:
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put_hex_table:
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.ascii "\n\r"
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.ascii "0123456789abcdef"
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.asciz "Scanning external memory at 0x"
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msg1:
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.asciz "Found XRAM top at 0x"
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crlf:
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.asciz "\n\r"
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space:
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.asciz " "
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msg_mirror:
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.asciz "hit mirror!\n\r"
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msg_bad:
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.asciz "bad readback!\n\r"
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msg2:
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.asciz "\n\rDumping the first few words of FLASH at address 0x"
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.set reorder
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msg0:
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.end entry
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.ascii "\n\r"
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.asciz "Scanning external memory at 0x"
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msg1:
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.asciz "Found XRAM top at 0x"
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crlf:
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.asciz "\n\r"
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space:
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.asciz " "
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msg_mirror:
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.asciz "hit mirror!\n\r"
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msg_bad:
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.asciz "bad readback!\n\r"
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msg2:
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.asciz "\n\rDumping the first few words of FLASH at address 0x"
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msg3:
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.ascii "\n\rTesting code execution from SRAM... "
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.asciz "if you see this, it worked\n\r"
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.set reorder
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.end entry
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No newline at end of file
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No newline at end of file
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No newline at end of file
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No newline at end of file
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