What is the symbolic address of the first byte
of the .data section?
tape
What main storage address will it have at run time?
0x10000000
The main storage address for the first byte of the data section is 0x10000000 by default (of the SPIM assembler). There is nothing in the program that says this.
The SPIM display shows data in groups of 4-byte words with the most significant byte on the left. This makes the data readable by humans. Within each group of four, the byte with the lowest address is on the right. Here is how SPIM looks after the low-order byte of the register has been stored to the buffer:
Register $9 has been loaded with the bit pattern 0x12345678.
The low-order byte has been stored where it should be in memory, although you have to look at the display carefully to see this. (Recall that SPIM displays each group of four bytes in backwards order to make reading little-endian integers easier.)
Which byte of $9 should go into address $0x10000000?