[video member=miotatsu stream_platform=twitch project=riscy title="Hello World in RISC-V ASM (2/2)" vod_platform=youtube id=bFsmu0mcM-k annotator=Miblo]
[0:01][Welcome to the stream][:speech]
[0:33][Review additions to the Useful Links: unistd.h[ref
    site=GitHub
    page="linux / include / uapi / asm-generic / unistd.h"
    url=https://github.com/torvalds/linux/blob/master/include/uapi/asm-generic/unistd.h] and RISC-V: Linux Syscall Interface[ref
        site=Sourceware
        page="[PATCH 10/12] RISC-V: Linux Syscall Interface"
        url=https://sourceware.org/ml/libc-alpha/2017-06/msg00626.html]][:research]
[2:48][@polytomous][Unfortunately don't have time to watch, but I just came by to say that your title is great]
[3:02][Continue reading through the RISC-V Linux Syscall Interface[ref
        site=Sourceware
        page="[PATCH 10/12] RISC-V: Linux Syscall Interface"
        url=https://sourceware.org/ml/libc-alpha/2017-06/msg00626.html]][:research]
[4:16][@polytomous][You best stream soon so I can actually watch you work on this project[ref
    site=YouTube
    page="RISCY BUSINESS"
    url=http://riscy.tv/]]
[4:55][Finish reading through the RISC-V Linux Syscall Interface[ref
        site=Sourceware
        page="[PATCH 10/12] RISC-V: Linux Syscall Interface"
        url=https://sourceware.org/ml/libc-alpha/2017-06/msg00626.html]][:research]
[5:34][Return to hello.S assembly and include the li and mv instructions in loop 1][:asm]
[6:45][@JumpOnMeh][Hi, are you coding on a Raspberry Pi?]
[7:32][Lower the exit call in main() from hula to assembly][:asm]
[8:58][@JumpOnMeh][If you don't mind me asking, what is RISC-V?[ref
    site=RISC-V
    url=https://riscv.org/]]
[11:02][Set up to lower the return call in main() from hula to assembly][:asm :speech]
[11:13][@JumpOnMeh][I'm taking a degree in comp sci right now. Kinda interested in learning new languages][:language]
[11:40][Plug ~bitwise[ref
    site=Bitwise
    url=https://bitwise.handmade.network/]][:speech]
[13:14][Lower the return call in main() from hula to assembly][:asm]
[14:27][Compare our newly written RISC-V assembly with hello.S in the repo,[ref
    site=GitLab
    page="hula / hello.S"
    url=https://gitlab.com/riscy-business/hula/blob/master/hello.S] and consult the RISC-V ELF psABI specification[ref
        site=GitHub
        page="RISC-V ELF psABI specification"
        url=https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md] for documentation on the stack frame][:research]
[17:54][Push the return address of main onto the stack][:asm]
[21:14][A few words on generating the code for multiple returns, wondering what [@pervognsen Per] has to say about it][:"code generation" :speech]
[22:12][Enable main to correctly return from all branches, and offset the stack pointer[ref
    site=GitLab
    page="hula / hello.S"
    url=https://gitlab.com/riscy-business/hula/blob/master/hello.S]][:asm]
[30:32][A few words on using the temporary "a" registers, and the possible :performance ramifications of being tight with register usage][:speech]
[32:31][Enable main to reuse the a1 register][:asm]
[34:28][Fix main to correctly break out of the print loop][:asm]
[36:48][Read through hello.S to check it all looks correct][:asm :research]
[40:08][Fix _start to correctly pop the loaded word off the stack][:asm]
[40:31][Finish reading through hello.S and consider it all good][:asm :research]
[41:15][Assemble our program to see assembly errors][:asm]
[42:13][Remove comment and fix assembly errors][:asm]
[42:42][Assemble our program to see errors on bez and beq][:asm]
[44:27][Grab the RISC-V Reader[ref
    title="RISC-V Reader"
    author="David Patterson and Andrew Waterman"
    publisher="Strawberry Canyon"
    isbn=9780999249116
    url=http://www.riscvbook.com/]][:admin]
[45:24][Rename bez to beqz, and fix our beq calls, in conjunction with the RISC-V Reader[ref
    title="RISC-V Reader"
    author="David Patterson and Andrew Waterman"
    publisher="Strawberry Canyon"
    isbn=9780999249116
    url=http://www.riscvbook.com/]][:asm]
[46:48][Consult the RISC-V Reader[ref
    title="RISC-V Reader"
    author="David Patterson and Andrew Waterman"
    publisher="Strawberry Canyon"
    isbn=9780999249116
    url=http://www.riscvbook.com/] for information on loading into the frame pointer][:asm :research]
[51:12][Try to make _start load 0 into s0 rather than fp][:asm]
[51:55][Assemble it to see that this fixed that error][:asm]
[52:44][Stick .section in front of .rodata as per the RISC-V Reader[ref
    title="RISC-V Reader"
    author="David Patterson and Andrew Waterman"
    publisher="Strawberry Canyon"
    isbn=9780999249116
    url=http://www.riscvbook.com/]][:asm]
[53:08][Assemble it successfully][:asm]
[54:07][Link our program with ld][:asm]
[54:20][:Run it to see that it works][:asm]
[54:41][Inspect our binary][:research]
[56:00][On writing this program as an example of code that hula should compile to][:asm :language :speech]
[56:18][Streamline the return code loads in main][:asm]
[1:00:37][Prevent _start from zeroing out the frame pointer][:asm]
[1:02:23][Assemble and link it][:asm]
[1:02:36][:Run it to see that it still works][:asm]
[1:02:45][Consider the episode done, with a glimpse into the future booting Fedora directly, hand-writing the machine code for our "Hello, World!" and covering compressed instructions][:asm :speech]
[1:07:32][Thoughts on avoiding :security vulnerabilities by owning the entire chain of production][:fabrication :hardware :speech]
[1:12:57][Further thoughts on the elegance of FORTH and its suitability for bootstrapping][:asm :speech]
[1:15:50][Glimpse into the future designing a custom case, streaming from our RISC-V system and building a Linux distribution for it][:speech]
[1:17:16][End this episode here][:speech]
[/video]