Diary/2020-5-5
RISC-V
関係の環境を再構築．
- Qemu
riscv-qemuから本家にマージされたってことだった
git clone --recursive https://git.qemu.org/git/qemu.git ./configure \ --target-list=riscv64-softmmu,riscv32-softmmu,riscv64-linux-user,riscv32-linux-user \ --prefix=$HOME/tools/riscv
- gccなど
crosstool-ngでインストール．
https://crosstool-ng.github.io/ から 1.24.0 をダウンロードしてビルド．
wget http://crosstool-ng.org/download/crosstool-ng/crosstool-ng-1.24.0.tar.bz2
tar xvf crosstool-ng-1.24.0.tar.bz2
cd crosstool-ng-1.24.0
./configure --prefix=/home/miyo/tools/crosstool-ng
export PATH=$HOME/tools/crosstool-ng/bin:$PATH
rehash
ct-ng update-samples
ct-ng list-samples | grep riscv
ct-ng riscv64-unknown-elf
vi .config # インストール先ディレクトリのCT_PREFIX_DIRを変更
# $HOME/tools/ct-ng/ にインストールすることにした
ct-ng build
- riscv-tools
git clone https://github.com/riscv/riscv-tools.git cd riscv-tools git submodule update --init --recursive export PATH=$HOME/tools/ct-ng/riscv64-unknown-elf/bin:$PATH export RISCV=$HOME/tools/riscv ./build.sh
- 動作確認
hello.s
.section .text .equ UART_ADDR, 0x10000000 #UART .global _start _start: la s0,message loop: lb a0,0(s0) addi s0,s0,1 beqz a0,halt jal putchar j loop putchar: li t0,UART_ADDR sb a0, 0(t0) ret halt: j halt .section .rodata message: .ascii "Hello, RISC-V\n\0"
linker.ld
OUTPUT_ARCH("riscv")
ENTRY(_start)
SECTIONS
{
. = 0x80000000;
.text : { *(.text) }
.rodata : { *(.rodata) }
.data : { *(.data) }
.bss : { *(.bss) }
}
ビルドして実行
riscv64-unknown-elf-gcc -march=rv64i -mabi=lp64 -nostartfiles -Tlinker.ld hello.s -o hello qemu-system-riscv64 -M virt -kernel hello -nographic
実行結果
miyo@tama:% qemu-system-riscv64 -M virt -kernel hello -nographic qemu-system-riscv64: warning: No -bios option specified. Not loading a firmware. qemu-system-riscv64: warning: This default will change in a future QEMU release. Please use the -bios option to avoid breakages when this happens. qemu-system-riscv64: warning: See QEMU's deprecation documentation for details. Hello, RISC-V # ここまで表示されたら Ctrl-a x を入力 QEMU: Terminated
objdumpでみてみる
miyo@tama:% riscv64-unknown-elf-objdump -s -d hello
hello: file format elf64-littleriscv
Contents of section .text:
80000000 17040000 1304c402 03050400 13041400 ................
80000010 630c0500 ef008000 6ff01fff b7020010 c.......o.......
80000020 2380a200 67800000 6f000000 #...g...o...
Contents of section .rodata:
8000002c 48656c6c 6f2c2052 4953432d 560a00 Hello, RISC-V..
Contents of section .riscv.attributes:
0000 41190000 00726973 63760001 0f000000 A....riscv......
0010 05727636 34693270 3000 .rv64i2p0.
Disassembly of section .text:
0000000080000000 <_start>:
80000000: 00000417 auipc s0,0x0
80000004: 02c40413 addi s0,s0,44 # 8000002c <message>
0000000080000008 <loop>:
80000008: 00040503 lb a0,0(s0)
8000000c: 00140413 addi s0,s0,1
80000010: 00050c63 beqz a0,80000028 <halt>
80000014: 008000ef jal ra,8000001c <putchar>
80000018: ff1ff06f j 80000008 <loop>
000000008000001c <putchar>:
8000001c: 100002b7 lui t0,0x10000
80000020: 00a28023 sb a0,0(t0) # 10000000 <UART_ADDR>
80000024: 00008067 ret
0000000080000028 <halt>:
80000028: 0000006f j 80000028 <halt>
objcopyしてhexdump
miyo@tama:% riscv64-unknown-elf-objcopy -O binary hello hello.bin miyo@tama:% hexdump hello.bin 0000000 0417 0000 0413 02c4 0503 0004 0413 0014 0000010 0c63 0005 00ef 0080 f06f ff1f 02b7 1000 0000020 8023 00a2 8067 0000 006f 0000 6548 6c6c 0000030 2c6f 5220 5349 2d43 0a56 0000 000003b