[reset] Adding reboot function by shutdown -r to PC-98

[tyama501]

Hello @ghaerr and @drachen6jp

This is the PR to add the shutdown -r reboot function for PC-98 by @drachen6jp .

I have cherry-picked his commit, then I have added reset-pc98.c and moved the function from the reset-stub.c.

I have confirmed it work with NP2 emulator.

Thank you!

[ghaerr]

Hello @tyama501,

Is there a chance you could rewrite using more readable C macros, something similar to reset-swan.c? This would allow the possible use of additional defines to use as port numbers or data constants as self-documentation. This would allow much easier understanding of what is being done. Something like:

#define PORT_CTRL  0x37  /* control port for ... */
#define PORT_xxxx  0xF0  /* special port for ... */

    outb(0x0B, PORT_CTRL);    /* send ... to ... control */
    outb(0x0F, PORT_CTRL);
    if (inb(0xF0) & 2)       /* V30 */
        outb(0x07, 0xF0);    /* send .. to ... control */
    else outb(0x00, 0xF0);
    asm("ljmp $0xFFFF,$0\n");

I realize that reset-ism.c is written all ASM, but the reason for that is that INT 15h is executed, for which there are no predefined macros to load registers beforehand.

Thank you!

[tyama501]

Hello @ghaerr

I have rewritten it.

Thank you.

[ghaerr]

Nice, thank you!