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| author | s-ol <s+removethis@s-ol.nu> | 2021-07-06 10:26:46 +0000 |
|---|---|---|
| committer | s-ol <s+removethis@s-ol.nu> | 2021-07-06 11:08:54 +0000 |
| commit | 631f09462050c8173dacb22a83e6ef3dacc3c8a1 (patch) | |
| tree | 4cbd147e158991e229ce1fc2001525078a020b83 /hello_world.subv | |
| parent | good helloworld example (diff) | |
| download | subv-631f09462050c8173dacb22a83e6ef3dacc3c8a1.tar.gz subv-631f09462050c8173dacb22a83e6ef3dacc3c8a1.zip | |
update README/ex example
Diffstat (limited to 'hello_world.subv')
| -rw-r--r-- | hello_world.subv | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/hello_world.subv b/hello_world.subv new file mode 100644 index 0000000..60d9065 --- /dev/null +++ b/hello_world.subv @@ -0,0 +1,43 @@ +== code 0x80000000 + # load mhartid CSR into t0, trap all but first Hart + 73/system 5/rd/t0 2/funct3/csrrs 0/rs/x0 f14/imm12/mhartid + 63/branch 1/subop/!= 5/rs/t0 0/rs/x0 0/off13 + +main: + # x4 = &message + # . load high bits + 37/lui a/rd/a0 Message/imm20hi + # . add low bits + 13/opi 0/subop/add 4/rd/x4 a/rs/a0 Message/imm12lo + # call print + 6f/jal 1/rd/ra print/off21 +loop: + # infinite loop + 6f/jal 0/rd/x0 loop/off21 + +print: + # load 0x10010000 (UART0) into t0 + 37/lui 5/rd/t0 0x10010/imm20 +print:loop: + # load unsigned byte at x4 + 03/load 4/subop/byte 6/rd/t1 a/rs/a0 0/imm12 + # break loop if zero + 63/branch 0/subop/== 6/rs/t1 0/rs/x0 print:break/off13 +print:spin: + # spin if FIFO is full + 03/load 2/subop/word 7/rd/t2 5/rs/t0 0/imm12 + 63/branch 4/subop/< 7/rs/t2 0/rs/x0 print:spin/off13 + # print char + 23/store 2/width/word 5/rs/t0 6/rs/t1 0/off12 + # increment x4 + 13/opi 0/subop/add a/rd/a0 a/rs/a0 1/imm12 + # jump back up + 6f/jal 0/rd/x0 print:loop/off21 +print:break: + # return + 67/jalr 0/subop 0/rd/x0 1/rs/ra 0/off12 + +== data 0x80500000 +Message: + # "Hello World!\n\0" + 48/8 65/8 6c/8 6c/8 6f/8 20/8 77/8 6f/8 72/8 6c/8 64/8 21/8 0a/8 00/8 |