ref: 74e47cdeb4f9b8d81766c24391bac05f87922115
dir: /kern/devroot.c/
#include "u.h" #include "lib.h" #include "dat.h" #include "fns.h" #include "error.h" enum { Qdir = 0, Qboot = 0x1000, Qmnt = 0x2000, Qfactotum, Nrootfiles = 32, Nbootfiles = 32, Nmntfiles = 2, }; typedef struct Dirlist Dirlist; struct Dirlist { uint base; Dirtab *dir; uchar **data; int ndir; int mdir; }; static Dirtab rootdir[Nrootfiles] = { "#/", {Qdir, 0, QTDIR}, 0, DMDIR|0555, "boot", {Qboot, 0, QTDIR}, 0, DMDIR|0555, "mnt", {Qmnt, 0, QTDIR}, 0, DMDIR|0555, }; static uchar *rootdata[Nrootfiles]; static Dirlist rootlist = { 0, rootdir, rootdata, 3, Nrootfiles }; static Dirtab bootdir[Nbootfiles] = { "boot", {Qboot, 0, QTDIR}, 0, DMDIR|0555, }; static uchar *bootdata[Nbootfiles]; static Dirlist bootlist = { Qboot, bootdir, bootdata, 1, Nbootfiles }; static uchar *mntdata[Nmntfiles]; static Dirtab mntdir[Nmntfiles] = { "mnt", {Qmnt, 0, QTDIR}, 0, DMDIR|0555, "factotum", {Qfactotum, 0, QTDIR}, 0, DMDIR|0555, }; static Dirlist mntlist = { Qmnt, mntdir, mntdata, 2, Nmntfiles }; /* * add a file to the list */ static void addlist(Dirlist *l, char *name, uchar *contents, ulong len, int perm) { Dirtab *d; if(l->ndir >= l->mdir) panic("too many root files"); l->data[l->ndir] = contents; d = &l->dir[l->ndir]; strcpy(d->name, name); d->length = len; d->perm = perm; d->qid.type = 0; d->qid.vers = 0; d->qid.path = ++l->ndir + l->base; if(perm & DMDIR) d->qid.type |= QTDIR; } /* * add a root file */ void addbootfile(char *name, uchar *contents, ulong len) { addlist(&bootlist, name, contents, len, 0555); } /* * add a root directory */ static void addrootdir(char *name) { addlist(&rootlist, name, nil, 0, DMDIR|0555); } static void rootreset(void) { addrootdir("bin"); addrootdir("dev"); addrootdir("env"); addrootdir("fd"); addrootdir("net"); addrootdir("net.alt"); addrootdir("proc"); addrootdir("root"); addrootdir("srv"); } static Chan* rootattach(char *spec) { return devattach('/', spec); } static int rootgen(Chan *c, char *name, Dirtab *dirt, int ndirt, int s, Dir *dp) { int t; Dirtab *d; Dirlist *l; USED(dirt); USED(ndirt); switch((int)c->qid.path){ case Qdir: if(s == DEVDOTDOT){ Qid tqiddir = {Qdir, 0, QTDIR}; devdir(c, tqiddir, "#/", 0, eve, 0555, dp); return 1; } return devgen(c, name, rootlist.dir, rootlist.ndir, s, dp); case Qmnt: if(s == DEVDOTDOT){ Qid tqiddir = {Qdir, 0, QTDIR}; devdir(c, tqiddir, "#/", 0, eve, 0555, dp); return 1; } return devgen(c, name, mntlist.dir, mntlist.ndir, s, dp); case Qboot: if(s == DEVDOTDOT){ Qid tqiddir = {Qdir, 0, QTDIR}; devdir(c, tqiddir, "#/", 0, eve, 0555, dp); return 1; } return devgen(c, name, bootlist.dir, bootlist.ndir, s, dp); default: if(s == DEVDOTDOT){ Qid tqiddir = {Qdir, 0, QTDIR}; tqiddir.path = c->qid.path&0xF000; devdir(c, tqiddir, "#/", 0, eve, 0555, dp); return 1; } if(s != 0) return -1; switch((int)c->qid.path & 0xF000){ case Qdir: t = c->qid.path-1; l = &rootlist; break; case Qboot: t = c->qid.path - Qboot - 1; l = &bootlist; break; case Qmnt: t = c->qid.path - Qmnt - 1; l = &mntlist; break; default: return -1; } if(t >= l->ndir) return -1; if(t < 0){ print("rootgen %llud %d %d\n", c->qid.path, s, t); panic("whoops"); } d = &l->dir[t]; devdir(c, d->qid, d->name, d->length, eve, d->perm, dp); return 1; } return -1; } static Walkqid* rootwalk(Chan *c, Chan *nc, char **name, int nname) { return devwalk(c, nc, name, nname, nil, 0, rootgen); } static int rootstat(Chan *c, uchar *dp, int n) { return devstat(c, dp, n, nil, 0, rootgen); } static Chan* rootopen(Chan *c, int omode) { return devopen(c, omode, nil, 0, devgen); } /* * sysremove() knows this is a nop */ static void rootclose(Chan *c) { USED(c); } static long rootread(Chan *c, void *buf, long n, vlong off) { ulong t; Dirtab *d; Dirlist *l; uchar *data; ulong offset = off; t = c->qid.path; switch(t){ case Qdir: case Qboot: case Qmnt: return devdirread(c, buf, n, nil, 0, rootgen); } if(t&Qboot) l = &bootlist; else if(t&Qmnt) l = &mntlist; else l = &bootlist; t &= 0xFFF; t--; if(t >= l->ndir) error(Egreg); d = &l->dir[t]; data = l->data[t]; if(offset >= d->length) return 0; if(offset+n > d->length) n = d->length - offset; memmove(buf, data+offset, n); return n; } static long rootwrite(Chan *c, void *v, long n, vlong o) { USED(c); USED(v); USED(n); USED(o); error(Egreg); return 0; } Dev rootdevtab = { '/', "root", rootreset, devinit, devshutdown, rootattach, rootwalk, rootstat, rootopen, devcreate, rootclose, rootread, devbread, rootwrite, devbwrite, devremove, devwstat, };