diff options
Diffstat (limited to 'sys/boot/i386/zfsboot/zfsboot.c')
-rw-r--r-- | sys/boot/i386/zfsboot/zfsboot.c | 944 |
1 files changed, 944 insertions, 0 deletions
diff --git a/sys/boot/i386/zfsboot/zfsboot.c b/sys/boot/i386/zfsboot/zfsboot.c new file mode 100644 index 0000000..9b0a465 --- /dev/null +++ b/sys/boot/i386/zfsboot/zfsboot.c @@ -0,0 +1,944 @@ +/*- + * Copyright (c) 1998 Robert Nordier + * All rights reserved. + * + * Redistribution and use in source and binary forms are freely + * permitted provided that the above copyright notice and this + * paragraph and the following disclaimer are duplicated in all + * such forms. + * + * This software is provided "AS IS" and without any express or + * implied warranties, including, without limitation, the implied + * warranties of merchantability and fitness for a particular + * purpose. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/errno.h> +#include <sys/diskmbr.h> +#include <sys/reboot.h> +#include <sys/queue.h> + +#include <machine/bootinfo.h> +#include <machine/elf.h> + +#include <stdarg.h> +#include <stddef.h> + +#include <a.out.h> + +#include <btxv86.h> + +#include "zfsboot.h" +#include "lib.h" + +#define IO_KEYBOARD 1 +#define IO_SERIAL 2 + +#define SECOND 18 /* Circa that many ticks in a second. */ + +#define RBX_ASKNAME 0x0 /* -a */ +#define RBX_SINGLE 0x1 /* -s */ +/* 0x2 is reserved for log2(RB_NOSYNC). */ +/* 0x3 is reserved for log2(RB_HALT). */ +/* 0x4 is reserved for log2(RB_INITNAME). */ +#define RBX_DFLTROOT 0x5 /* -r */ +#define RBX_KDB 0x6 /* -d */ +/* 0x7 is reserved for log2(RB_RDONLY). */ +/* 0x8 is reserved for log2(RB_DUMP). */ +/* 0x9 is reserved for log2(RB_MINIROOT). */ +#define RBX_CONFIG 0xa /* -c */ +#define RBX_VERBOSE 0xb /* -v */ +#define RBX_SERIAL 0xc /* -h */ +#define RBX_CDROM 0xd /* -C */ +/* 0xe is reserved for log2(RB_POWEROFF). */ +#define RBX_GDB 0xf /* -g */ +#define RBX_MUTE 0x10 /* -m */ +/* 0x11 is reserved for log2(RB_SELFTEST). */ +/* 0x12 is reserved for boot programs. */ +/* 0x13 is reserved for boot programs. */ +#define RBX_PAUSE 0x14 /* -p */ +#define RBX_QUIET 0x15 /* -q */ +#define RBX_NOINTR 0x1c /* -n */ +/* 0x1d is reserved for log2(RB_MULTIPLE) and is just misnamed here. */ +#define RBX_DUAL 0x1d /* -D */ +/* 0x1f is reserved for log2(RB_BOOTINFO). */ + +/* pass: -a, -s, -r, -d, -c, -v, -h, -C, -g, -m, -p, -D */ +#define RBX_MASK (OPT_SET(RBX_ASKNAME) | OPT_SET(RBX_SINGLE) | \ + OPT_SET(RBX_DFLTROOT) | OPT_SET(RBX_KDB ) | \ + OPT_SET(RBX_CONFIG) | OPT_SET(RBX_VERBOSE) | \ + OPT_SET(RBX_SERIAL) | OPT_SET(RBX_CDROM) | \ + OPT_SET(RBX_GDB ) | OPT_SET(RBX_MUTE) | \ + OPT_SET(RBX_PAUSE) | OPT_SET(RBX_DUAL)) + +/* Hint to loader that we came from ZFS */ +#define KARGS_FLAGS_ZFS 0x4 + +#define PATH_CONFIG "/boot.config" +#define PATH_BOOT3 "/boot/loader" +#define PATH_KERNEL "/boot/kernel/kernel" + +#define ARGS 0x900 +#define NOPT 14 +#define NDEV 3 +#define MEM_BASE 0x12 +#define MEM_EXT 0x15 +#define V86_CY(x) ((x) & 1) +#define V86_ZR(x) ((x) & 0x40) + +#define DRV_HARD 0x80 +#define DRV_MASK 0x7f + +#define TYPE_AD 0 +#define TYPE_DA 1 +#define TYPE_MAXHARD TYPE_DA +#define TYPE_FD 2 + +#define OPT_SET(opt) (1 << (opt)) +#define OPT_CHECK(opt) ((opts) & OPT_SET(opt)) + +extern uint32_t _end; + +static const char optstr[NOPT] = "DhaCcdgmnpqrsv"; /* Also 'P', 'S' */ +static const unsigned char flags[NOPT] = { + RBX_DUAL, + RBX_SERIAL, + RBX_ASKNAME, + RBX_CDROM, + RBX_CONFIG, + RBX_KDB, + RBX_GDB, + RBX_MUTE, + RBX_NOINTR, + RBX_PAUSE, + RBX_QUIET, + RBX_DFLTROOT, + RBX_SINGLE, + RBX_VERBOSE +}; + +static const char *const dev_nm[NDEV] = {"ad", "da", "fd"}; +static const unsigned char dev_maj[NDEV] = {30, 4, 2}; + +struct dsk { + unsigned drive; + unsigned type; + unsigned unit; + unsigned slice; + unsigned part; + unsigned start; + int init; +}; +static char cmd[512]; +static char kname[1024]; +static uint32_t opts; +static int comspeed = SIOSPD; +static struct bootinfo bootinfo; +static uint32_t bootdev; +static uint8_t ioctrl = IO_KEYBOARD; + +/* Buffers that must not span a 64k boundary. */ +#define READ_BUF_SIZE 8192 +struct dmadat { + char rdbuf[READ_BUF_SIZE]; /* for reading large things */ + char secbuf[READ_BUF_SIZE]; /* for MBR/disklabel */ +}; +static struct dmadat *dmadat; + +void exit(int); +static void load(void); +static int parse(void); +static void printf(const char *,...); +static void putchar(int); +static uint32_t memsize(void); +static int drvread(struct dsk *, void *, unsigned, unsigned); +static int keyhit(unsigned); +static int xputc(int); +static int xgetc(int); +static int getc(int); + +static void memcpy(void *, const void *, int); +static void +memcpy(void *dst, const void *src, int len) +{ + const char *s = src; + char *d = dst; + + while (len--) + *d++ = *s++; +} + +static void +strcpy(char *dst, const char *src) +{ + while (*src) + *dst++ = *src++; + *dst++ = 0; +} + +static void +strcat(char *dst, const char *src) +{ + while (*dst) + dst++; + while (*src) + *dst++ = *src++; + *dst++ = 0; +} + +static int +strcmp(const char *s1, const char *s2) +{ + for (; *s1 == *s2 && *s1; s1++, s2++); + return (unsigned char)*s1 - (unsigned char)*s2; +} + +static const char * +strchr(const char *s, char ch) +{ + for (; *s; s++) + if (*s == ch) + return s; + return 0; +} + +static int +memcmp(const void *p1, const void *p2, size_t n) +{ + const char *s1 = (const char *) p1; + const char *s2 = (const char *) p2; + for (; n > 0 && *s1 == *s2; s1++, s2++, n--); + if (n) + return (unsigned char)*s1 - (unsigned char)*s2; + else + return 0; +} + +static void +memset(void *p, char val, size_t n) +{ + char *s = (char *) p; + while (n--) + *s++ = val; +} + +static void * +malloc(size_t n) +{ + static char *heap_next; + static char *heap_end; + + if (!heap_next) { + heap_next = (char *) dmadat + sizeof(*dmadat); + heap_end = (char *) (640*1024); + } + + char *p = heap_next; + if (p + n > heap_end) { + printf("malloc failure\n"); + for (;;) + ; + return 0; + } + heap_next += n; + return p; +} + +static size_t +strlen(const char *s) +{ + size_t len = 0; + while (*s++) + len++; + return len; +} + +static char * +strdup(const char *s) +{ + char *p = malloc(strlen(s) + 1); + strcpy(p, s); + return p; +} + +#include "zfsimpl.c" + +/* + * Read from a dnode (which must be from a ZPL filesystem). + */ +static int +zfs_read(spa_t *spa, const dnode_phys_t *dnode, off_t *offp, void *start, size_t size) +{ + const znode_phys_t *zp = (const znode_phys_t *) dnode->dn_bonus; + size_t n; + int rc; + + n = size; + if (*offp + n > zp->zp_size) + n = zp->zp_size - *offp; + + rc = dnode_read(spa, dnode, *offp, start, n); + if (rc) + return (-1); + *offp += n; + + return (n); +} + +/* + * Current ZFS pool + */ +spa_t *spa; + +/* + * A wrapper for dskread that doesn't have to worry about whether the + * buffer pointer crosses a 64k boundary. + */ +static int +vdev_read(vdev_t *vdev, void *priv, off_t off, void *buf, size_t bytes) +{ + char *p; + unsigned int lba, nb; + struct dsk *dsk = (struct dsk *) priv; + + if ((off & (DEV_BSIZE - 1)) || (bytes & (DEV_BSIZE - 1))) + return -1; + + p = buf; + lba = off / DEV_BSIZE; + while (bytes > 0) { + nb = bytes / DEV_BSIZE; + if (nb > READ_BUF_SIZE / DEV_BSIZE) + nb = READ_BUF_SIZE / DEV_BSIZE; + if (drvread(dsk, dmadat->rdbuf, lba, nb)) + return -1; + memcpy(p, dmadat->rdbuf, nb * DEV_BSIZE); + p += nb * DEV_BSIZE; + lba += nb; + bytes -= nb * DEV_BSIZE; + } + + return 0; +} + +static int +xfsread(const dnode_phys_t *dnode, off_t *offp, void *buf, size_t nbyte) +{ + if ((size_t)zfs_read(spa, dnode, offp, buf, nbyte) != nbyte) { + printf("Invalid %s\n", "format"); + return -1; + } + return 0; +} + +static inline uint32_t +memsize(void) +{ + v86.addr = MEM_EXT; + v86.eax = 0x8800; + v86int(); + return v86.eax; +} + +static inline void +getstr(void) +{ + char *s; + int c; + + s = cmd; + for (;;) { + switch (c = xgetc(0)) { + case 0: + break; + case '\177': + case '\b': + if (s > cmd) { + s--; + printf("\b \b"); + } + break; + case '\n': + case '\r': + *s = 0; + return; + default: + if (s - cmd < sizeof(cmd) - 1) + *s++ = c; + putchar(c); + } + } +} + +static inline void +putc(int c) +{ + v86.addr = 0x10; + v86.eax = 0xe00 | (c & 0xff); + v86.ebx = 0x7; + v86int(); +} + +/* + * Try to detect a device supported by the legacy int13 BIOS + */ +static int +int13probe(int drive) +{ + v86.ctl = V86_FLAGS; + v86.addr = 0x13; + v86.eax = 0x800; + v86.edx = drive; + v86int(); + + if (!(v86.efl & 0x1) && /* carry clear */ + ((v86.edx & 0xff) != (drive & DRV_MASK))) { /* unit # OK */ + if ((v86.ecx & 0x3f) == 0) { /* absurd sector size */ + return(0); /* skip device */ + } + return (1); + } + return(0); +} + +static void +probe_drive(struct dsk *dsk, spa_t **spap) +{ + struct dos_partition *dp; + char *sec; + unsigned i; + + if (!int13probe(dsk->drive)) + return; + + /* + * If we find a vdev on the whole disk, stop here. Otherwise dig + * out the MBR and probe each slice in turn for a vdev. + */ + if (vdev_probe(vdev_read, dsk, spap) == 0) + return; + + sec = dmadat->secbuf; + dsk->start = 0; + if (drvread(dsk, sec, DOSBBSECTOR, 1)) + return; + dp = (void *)(sec + DOSPARTOFF); + + for (i = 0; i < NDOSPART; i++) { + if (!dp[i].dp_typ) + continue; + dsk->start = dp[i].dp_start; + if (vdev_probe(vdev_read, dsk, spap) == 0) { + /* + * We record the first pool we find (we will try to boot + * from that one. + */ + spap = 0; + + /* + * This slice had a vdev. We need a new dsk structure now + * sice the vdev now owns this one. + */ + struct dsk *newdsk; + newdsk = malloc(sizeof(struct dsk)); + *newdsk = *dsk; + dsk = newdsk; + } + } +} + +int +main(void) +{ + int autoboot, i; + dnode_phys_t dn; + off_t off; + struct dsk *dsk; + + dmadat = (void *)(roundup2(__base + (int32_t)&_end, 0x10000) - __base); + v86.ctl = V86_FLAGS; + + dsk = malloc(sizeof(struct dsk)); + dsk->drive = *(uint8_t *)PTOV(ARGS); + dsk->type = dsk->drive & DRV_HARD ? TYPE_AD : TYPE_FD; + dsk->unit = dsk->drive & DRV_MASK; + dsk->slice = *(uint8_t *)PTOV(ARGS + 1) + 1; + dsk->part = 0; + dsk->start = 0; + dsk->init = 0; + + bootinfo.bi_version = BOOTINFO_VERSION; + bootinfo.bi_size = sizeof(bootinfo); + bootinfo.bi_basemem = 0; /* XXX will be filled by loader or kernel */ + bootinfo.bi_extmem = memsize(); + bootinfo.bi_memsizes_valid++; + bootinfo.bi_bios_dev = dsk->drive; + + bootdev = MAKEBOOTDEV(dev_maj[dsk->type], + dsk->slice, dsk->unit, dsk->part), + + /* Process configuration file */ + + autoboot = 1; + + zfs_init(); + + /* + * Probe the boot drive first - we will try to boot from whatever + * pool we find on that drive. + */ + probe_drive(dsk, &spa); + + /* + * Probe the rest of the drives that the bios knows about. This + * will find any other available pools and it may fill in missing + * vdevs for the boot pool. + */ + for (i = 0; i < 4; i++) { + if ((i | DRV_HARD) == *(uint8_t *)PTOV(ARGS)) + continue; + + dsk = malloc(sizeof(struct dsk)); + dsk->drive = i | DRV_HARD; + dsk->type = dsk->drive & TYPE_AD; + dsk->unit = i; + dsk->slice = 0; + dsk->part = 0; + dsk->start = 0; + dsk->init = 0; + probe_drive(dsk, 0); + } + + /* + * If we didn't find a pool on the boot drive, default to the + * first pool we found, if any. + */ + if (!spa) { + spa = STAILQ_FIRST(&zfs_pools); + if (!spa) { + printf("No ZFS pools located, can't boot\n"); + for (;;) + ; + } + } + + zfs_mount_pool(spa); + + if (zfs_lookup(spa, PATH_CONFIG, &dn) == 0) { + off = 0; + xfsread(&dn, &off, cmd, sizeof(cmd)); + } + + if (*cmd) { + if (parse()) + autoboot = 0; + if (!OPT_CHECK(RBX_QUIET)) + printf("%s: %s", PATH_CONFIG, cmd); + /* Do not process this command twice */ + *cmd = 0; + } + + /* + * Try to exec stage 3 boot loader. If interrupted by a keypress, + * or in case of failure, try to load a kernel directly instead. + */ + + if (autoboot && !*kname) { + memcpy(kname, PATH_BOOT3, sizeof(PATH_BOOT3)); + if (!keyhit(3*SECOND)) { + load(); + memcpy(kname, PATH_KERNEL, sizeof(PATH_KERNEL)); + } + } + + /* Present the user with the boot2 prompt. */ + + for (;;) { + if (!autoboot || !OPT_CHECK(RBX_QUIET)) + printf("\nFreeBSD/i386 boot\n" + "Default: %s:%s\n" + "boot: ", + spa->spa_name, kname); + if (ioctrl & IO_SERIAL) + sio_flush(); + if (!autoboot || keyhit(5*SECOND)) + getstr(); + else if (!autoboot || !OPT_CHECK(RBX_QUIET)) + putchar('\n'); + autoboot = 0; + if (parse()) + putchar('\a'); + else + load(); + } +} + +/* XXX - Needed for btxld to link the boot2 binary; do not remove. */ +void +exit(int x) +{ +} + +static void +load(void) +{ + union { + struct exec ex; + Elf32_Ehdr eh; + } hdr; + static Elf32_Phdr ep[2]; + static Elf32_Shdr es[2]; + caddr_t p; + dnode_phys_t dn; + off_t off; + uint32_t addr, x; + int fmt, i, j; + + if (zfs_lookup(spa, kname, &dn)) { + return; + } + off = 0; + if (xfsread(&dn, &off, &hdr, sizeof(hdr))) + return; + if (N_GETMAGIC(hdr.ex) == ZMAGIC) + fmt = 0; + else if (IS_ELF(hdr.eh)) + fmt = 1; + else { + printf("Invalid %s\n", "format"); + return; + } + if (fmt == 0) { + addr = hdr.ex.a_entry & 0xffffff; + p = PTOV(addr); + off = PAGE_SIZE; + if (xfsread(&dn, &off, p, hdr.ex.a_text)) + return; + p += roundup2(hdr.ex.a_text, PAGE_SIZE); + if (xfsread(&dn, &off, p, hdr.ex.a_data)) + return; + p += hdr.ex.a_data + roundup2(hdr.ex.a_bss, PAGE_SIZE); + bootinfo.bi_symtab = VTOP(p); + memcpy(p, &hdr.ex.a_syms, sizeof(hdr.ex.a_syms)); + p += sizeof(hdr.ex.a_syms); + if (hdr.ex.a_syms) { + if (xfsread(&dn, &off, p, hdr.ex.a_syms)) + return; + p += hdr.ex.a_syms; + if (xfsread(&dn, &off, p, sizeof(int))) + return; + x = *(uint32_t *)p; + p += sizeof(int); + x -= sizeof(int); + if (xfsread(&dn, &off, p, x)) + return; + p += x; + } + } else { + off = hdr.eh.e_phoff; + for (j = i = 0; i < hdr.eh.e_phnum && j < 2; i++) { + if (xfsread(&dn, &off, ep + j, sizeof(ep[0]))) + return; + if (ep[j].p_type == PT_LOAD) + j++; + } + for (i = 0; i < 2; i++) { + p = PTOV(ep[i].p_paddr & 0xffffff); + off = ep[i].p_offset; + if (xfsread(&dn, &off, p, ep[i].p_filesz)) + return; + } + p += roundup2(ep[1].p_memsz, PAGE_SIZE); + bootinfo.bi_symtab = VTOP(p); + if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) { + off = hdr.eh.e_shoff + sizeof(es[0]) * + (hdr.eh.e_shstrndx + 1); + if (xfsread(&dn, &off, &es, sizeof(es))) + return; + for (i = 0; i < 2; i++) { + memcpy(p, &es[i].sh_size, sizeof(es[i].sh_size)); + p += sizeof(es[i].sh_size); + off = es[i].sh_offset; + if (xfsread(&dn, &off, p, es[i].sh_size)) + return; + p += es[i].sh_size; + } + } + addr = hdr.eh.e_entry & 0xffffff; + } + bootinfo.bi_esymtab = VTOP(p); + bootinfo.bi_kernelname = VTOP(kname); + __exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK), + bootdev, + KARGS_FLAGS_ZFS, + (uint32_t) spa->spa_guid, + (uint32_t) (spa->spa_guid >> 32), + VTOP(&bootinfo)); +} + +static int +parse() +{ + char *arg = cmd; + char *ep, *p, *q; + const char *cp; + //unsigned int drv; + int c, i, j; + + while ((c = *arg++)) { + if (c == ' ' || c == '\t' || c == '\n') + continue; + for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++); + ep = p; + if (*p) + *p++ = 0; + if (c == '-') { + while ((c = *arg++)) { + if (c == 'P') { + if (*(uint8_t *)PTOV(0x496) & 0x10) { + cp = "yes"; + } else { + opts |= OPT_SET(RBX_DUAL) | OPT_SET(RBX_SERIAL); + cp = "no"; + } + printf("Keyboard: %s\n", cp); + continue; + } else if (c == 'S') { + j = 0; + while ((unsigned int)(i = *arg++ - '0') <= 9) + j = j * 10 + i; + if (j > 0 && i == -'0') { + comspeed = j; + break; + } + /* Fall through to error below ('S' not in optstr[]). */ + } + for (i = 0; c != optstr[i]; i++) + if (i == NOPT - 1) + return -1; + opts ^= OPT_SET(flags[i]); + } + ioctrl = OPT_CHECK(RBX_DUAL) ? (IO_SERIAL|IO_KEYBOARD) : + OPT_CHECK(RBX_SERIAL) ? IO_SERIAL : IO_KEYBOARD; + if (ioctrl & IO_SERIAL) + sio_init(115200 / comspeed); + } if (c == '?') { + dnode_phys_t dn; + + if (zfs_lookup(spa, arg, &dn) == 0) { + zap_list(spa, &dn); + } + return -1; + } else { + arg--; + + /* + * Report pool status if the comment is 'status'. Lets + * hope no-one wants to load /status as a kernel. + */ + if (!strcmp(arg, "status")) { + spa_all_status(); + return -1; + } + + /* + * If there is a colon, switch pools. + */ + q = (char *) strchr(arg, ':'); + if (q) { + spa_t *newspa; + + *q++ = 0; + newspa = spa_find_by_name(arg); + if (newspa) { + spa = newspa; + zfs_mount_pool(spa); + } else { + printf("\nCan't find ZFS pool %s\n", arg); + return -1; + } + arg = q; + } + if ((i = ep - arg)) { + if ((size_t)i >= sizeof(kname)) + return -1; + memcpy(kname, arg, i + 1); + } + } + arg = p; + } + return 0; +} + +static void +printf(const char *fmt,...) +{ + va_list ap; + char buf[10]; + char *s; + unsigned u; + int c; + int minus; + int prec; + int len; + int pad; + + va_start(ap, fmt); + while ((c = *fmt++)) { + if (c == '%') { + minus = 0; + prec = 0; + nextfmt: + c = *fmt++; + switch (c) { + case '-': + minus = 1; + goto nextfmt; + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + prec = 10 * prec + (c - '0'); + goto nextfmt; + case 'c': + putchar(va_arg(ap, int)); + continue; + case 's': + s = va_arg(ap, char *); + if (prec) { + len = strlen(s); + if (len < prec) + pad = prec - len; + else + pad = 0; + if (minus) + while (pad--) + putchar(' '); + for (; *s; s++) + putchar(*s); + if (!minus) + while (pad--) + putchar(' '); + } else { + for (; *s; s++) + putchar(*s); + } + continue; + case 'u': + u = va_arg(ap, unsigned); + s = buf; + do + *s++ = '0' + u % 10U; + while (u /= 10U); + while (--s >= buf) + putchar(*s); + continue; + } + } + putchar(c); + } + va_end(ap); + return; +} + +static void +putchar(int c) +{ + if (c == '\n') + xputc('\r'); + xputc(c); +} + +static int +drvread(struct dsk *dsk, void *buf, unsigned lba, unsigned nblk) +{ + static unsigned c = 0x2d5c7c2f; + + lba += dsk->start; + if (!OPT_CHECK(RBX_QUIET)) + printf("%c\b", c = c << 8 | c >> 24); + v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS; + v86.addr = XREADORG; /* call to xread in boot1 */ + v86.es = VTOPSEG(buf); + v86.eax = lba; + v86.ebx = VTOPOFF(buf); + v86.ecx = lba >> 16; + v86.edx = nblk << 8 | dsk->drive; + v86int(); + v86.ctl = V86_FLAGS; + if (V86_CY(v86.efl)) { + printf("error %u lba %u\n", v86.eax >> 8 & 0xff, lba); + return -1; + } + return 0; +} + +static int +keyhit(unsigned ticks) +{ + uint32_t t0, t1; + + if (OPT_CHECK(RBX_NOINTR)) + return 0; + t0 = 0; + for (;;) { + if (xgetc(1)) + return 1; + t1 = *(uint32_t *)PTOV(0x46c); + if (!t0) + t0 = t1; + if (t1 < t0 || t1 >= t0 + ticks) + return 0; + } +} + +static int +xputc(int c) +{ + if (ioctrl & IO_KEYBOARD) + putc(c); + if (ioctrl & IO_SERIAL) + sio_putc(c); + return c; +} + +static int +xgetc(int fn) +{ + if (OPT_CHECK(RBX_NOINTR)) + return 0; + for (;;) { + if (ioctrl & IO_KEYBOARD && getc(1)) + return fn ? 1 : getc(0); + if (ioctrl & IO_SERIAL && sio_ischar()) + return fn ? 1 : sio_getc(); + if (fn) + return 0; + } +} + +static int +getc(int fn) +{ + /* + * The extra comparison against zero is an attempt to work around + * what appears to be a bug in QEMU and Bochs. Both emulators + * sometimes report a key-press with scancode one and ascii zero + * when no such key is pressed in reality. As far as I can tell, + * this only happens shortly after a reboot. + */ + v86.addr = 0x16; + v86.eax = fn << 8; + v86int(); + return fn == 0 ? v86.eax & 0xff : (!V86_ZR(v86.efl) && (v86.eax & 0xff)); +} |