/* * boot driver for BIOS LBA devices * heavily dependent upon correct BIOS implementation */#include <u.h>#include "lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "io.h"#include "ureg.h"#include "fs.h" typedef uvlong Devbytes, Devsects; typedef struct Biosdrive Biosdrive; /* 1 drive -> ndevs */typedef struct Biosdev Biosdev; enum { Debug = 0, Maxdevs = 8, CF = 1, /* carry flag: indicates an error */ Flopid = 0, /* first floppy */ Baseid = 0x80, /* first disk */ Dap = 1<<0, Edd = 1<<2, /* bios calls: int 0x13 disk services */ Biosinit = 0, /* initialise disk & floppy ctlrs */ Biosdrvsts, Bioschsrdsects, Biosdrvparam = 8, Biosctlrinit, Biosreset = 0xd, /* reset disk */ Biosdrvrdy = 0x10, Biosdrvtype = 0x15, Biosckext = 0x41, Biosrdsect, Biosedrvparam = 0x48, /* disk types */ Typenone = 0, Typedisk = 3,}; struct Biosdrive { int ndevs;};struct Biosdev { Devbytes size; Devbytes offset; uchar id; /* drive number; e.g., 0x80 */ char type; ushort sectsz;}; typedef struct Extread { /* a device address packet */ uchar size; uchar unused1; uchar nsects; uchar unused2; ulong addr; /* segment:offset; ea = (segment<<4)+offset */ uvlong stsect; /* starting sector */} Extread;typedef struct Edrvparam { /* from edd 1.1 spec */ ushort size; /* max. buffer size */ ushort flags; ulong physcyls; ulong physheads; ulong phystracksects; uvlong physsects; ushort sectsz; void *dpte; /* ~0ull: invalid */ /* remainder from edd 3.0 spec */ ushort key; /* 0xbedd if present */ uchar dpilen; uchar unused1; ushort unused2; char bustype[4]; /* "PCI" or "ISA" */ char ifctype[8]; /* "ATA", "ATAPI", "SCSI", "USB", "1394", "FIBRE" */ uvlong ifcpath; uvlong devpath; uchar unused3; uchar dpicksum;} Edrvparam; void realmode(int intr, Ureg *ureg); /* from trap.c */ int onlybios0;int biosinited; static Biosdev bdev[Maxdevs];static Biosdrive bdrive;static Ureg regs; static int dreset(uchar drive);static Devbytes extgetsize(Biosdev *);static Devsects getsize(uchar drive, char *type);static int islba(uchar drive); /* * caller must zero or otherwise initialise *rp, * other than ax, bx, dx, si & ds. */static intbiosdiskcall(Ureg *rp, uchar op, ulong bx, ulong dx, ulong si){ rp->ax = op << 8; rp->bx = bx; rp->dx = dx; /* often drive id */ /* * ensure that addr fits in a short, * then jigger it and DS to avoid segment 0. */ if((si & 0xffff0000) != 0) print("biosdiskcall: address %#lux not a short\n", si); rp->ds = si >> 4; si &= 0xf; if((si & 0xffff0000) != ((si + 512 - 1) & 0xffff0000)) print("biosdiskcall: address %#lux too near segment boundary\n", si); rp->si = si; /* ds:si forms data access packet addr */ /* * *rp is copied into low memory (realmoderegs) and thence into * the machine registers before the BIOS call, and the registers are * copied into realmoderegs and thence into *rp after. */ realmode(0x13, rp); if (rp->flags & CF) { if (Debug && dx == Baseid) print("\nbiosdiskcall: int 0x13 op 0x%ux drive 0x%lux " "failed, ah error code 0x%ux\n", op, dx, (uchar)(rp->ax >> 8)); return -1; } return 0;} /* * Find out what the bios knows about devices. * our boot device could be usb; ghod only knows where it will appear. */intbiosinit(void){ int devid, lba, mask, lastbit; Devbytes size; char type; Biosdev *bdp; static int beenhere; /* 9pxeload can't use bios int 13 calls; they wedge the machine */ if (pxe || !biosload || onlybios0 || biosinited || beenhere) return 0; beenhere = 1; mask = lastbit = 0; for (devid = Baseid; devid < (1 << 8) && bdrive.ndevs < Maxdevs; devid++) { lba = islba(devid); if (lba < 0) break; /* don't reset; it seems to hang the bios */ if(!lba /* || devid != Baseid && dreset(devid) < 0 */ ) continue; type = Typenone; if (getsize(devid, &type) == 0) { /* no device, end of range */// devid &= ~0xf;// devid += 0x10;// devid--;// break; continue; } lastbit = 1 << bdrive.ndevs; mask |= lastbit; bdp = &bdev[bdrive.ndevs]; bdp->id = devid; bdp->type = type; size = extgetsize(bdp); bdp->size = size; print("bios%d: drive 0x%ux: %,llud bytes, type %d\n", bdrive.ndevs, devid, size, type); bdrive.ndevs++; } USED(lastbit);// islba(Baseid); /* do a successful operation to make bios happy again */ /* * some bioses seem to only be able to read from drive number 0x80 * and certainly can't read from the highest drive number when we * call them, even if there is only one. attempting to read from the * last drive number may yield a hung machine or a two-minute pause. */ if (bdrive.ndevs > 0) {#ifdef NOT_LAST_DRIVE if (bdrive.ndevs == 1) { print("biosinit: sorry, only one bios drive; " "can't read last one\n"); onlybios0 = 1; } else biosinited = 1; bdrive.ndevs--; /* omit last drive number; it can't be read */ mask &= ~lastbit;#else biosinited = 1;#endif } return mask;} voidbiosinitdev(int i, char *name){ if(i >= bdrive.ndevs) panic("biosinitdev"); sprint(name, "bios%d", i);} voidbiosprintdevs(int i){ if(i >= bdrive.ndevs){ print("got a print for %d, only got %d\n", i, bdrive.ndevs); panic("biosprintdevs"); } print(" bios%d", i);} intbiosboot(int dev, char *file, Boot *b){ Fs *fs; if(strncmp(file, "dos!", 4) == 0) file += 4; if(strchr(file, '!') != nil || strcmp(file, "") == 0) { print("syntax is bios0!file\n"); return -1; } fs = biosgetfspart(dev, "9fat", 1); if(fs == nil) return -1; return fsboot(fs, file, b);} static voiddump(void *addr, int wds){ unsigned i; ulong *p = addr; for (i = 0; i < wds; i++) print("%lux ", p[i]); if (i % 8 == 7) print("\n"); print("\n");} /* read n bytes at sector offset into a from drive id */longsectread(Biosdev *bdp, void *a, long n, Devsects offset){ uchar *biosparam, *cp; Extread *erp; if(n < 0 || n > bdp->sectsz) return -1; if(Debug) /* scribble on the buffer to provoke trouble */ memset((uchar *)BIOSXCHG, 'r', bdp->sectsz); // if(Debug)// print("drive ready %#ux...", bdp->id);// memset(®s, 0, sizeof regs);// if (biosdiskcall(®s, Biosdrvrdy, 0, bdp->id, 0) < 0)// print("not ready\n"); /* space for a big, optical-size sector, just in case... */ biosparam = (uchar *)BIOSXCHG + 2*1024; /* read into BIOSXCHG */ erp = (Extread *)biosparam; memset(erp, 0, sizeof *erp); erp->size = sizeof *erp; erp->nsects = 1; erp->addr = PADDR(BIOSXCHG); erp->stsect = offset; /* * ensure that addr fits in a short, * then jigger it to avoid segment 0. */ if((erp->addr & 0xffff0000) != 0) print("sectread: address %#lux not a short\n", erp->addr); erp->addr = ((erp->addr & 0xffff) >> 4) << 16 | (erp->addr & 0xf); if((erp->addr & 0xffff0000) != ((erp->addr + 512 - 1) & 0xffff0000)) print("sectread: address %#lux too near segment boundary\n", erp->addr); if (0 && Debug) print("reading drive %#ux offset %lld into seg:off %lux:%ux...", bdp->id, offset, erp->addr>>16, (ushort)erp->addr); if (Debug) dump(erp, sizeof *erp / 4); memset(®s, 0, sizeof regs); regs.es = erp->addr >> 16; if (biosdiskcall(®s, Biosrdsect, (ushort)erp->addr, bdp->id, PADDR(erp)) < 0) { print("sectread: bios failed to read %ld @ sector %lld of 0x%ux\n", n, offset, bdp->id); return -1; } /* copy into caller's buffer */ memmove(a, (char *)BIOSXCHG, n); if(0 && Debug){ cp = (uchar *)BIOSXCHG; print("-%ux %ux %ux %ux--%16.16s-\n", cp[0], cp[1], cp[2], cp[3], (char *)cp + 480); } return n;} /* not tested yet. */static intdreset(uchar drive){ print("devbios: resetting %#ux...", drive); memset(®s, 0, sizeof regs); if (biosdiskcall(®s, Biosinit, 0, drive, 0) < 0) print("failed"); print("\n"); return regs.ax? -1: 0; /* ax!=0 on error */} static intislba(uchar drive){ memset(®s, 0, sizeof regs); if (biosdiskcall(®s, Biosckext, 0x55aa, drive, 0) < 0) { /* * we have an old bios without extensions, in theory. * in practice, there may just be no drive for this number. */// print("islba: drive %ux: Biosckext failed\n", drive); return -1; } if(regs.bx != 0xaa55){ print("islba: buggy bios: drive %#ux extension check returned " "%lux in bx\n", drive, regs.bx); return -1; } if (Debug) print("islba: drive 0x%ux extensions version %d.%d cx 0x%lux\n", drive, (uchar)(regs.ax >> 8), (uchar)regs.ax, regs.cx); /* cx has Edd, Dap bits */ return regs.cx & Dap;} /* * works so so... some floppies are 0x80+x when they shouldn't be, * and report lba even if they cannot... */static Devsectsgetsize(uchar id, char *typep){ int dtype; memset(®s, 0, sizeof regs); if (biosdiskcall(®s, Biosdrvtype, 0x55aa, id, 0) < 0) return 0; dtype = (ushort)regs.ax >> 8; *typep = dtype; if(dtype == Typenone){ print("no such device 0x%ux of type %d\n", id, dtype); return 0; } if(dtype != Typedisk){ print("non-disk device 0x%ux of type %d\n", id, dtype); return 0; } return (ushort)regs.cx | regs.dx << 16;} /* extended get size */static Devbytesextgetsize(Biosdev *bdp){ Edrvparam *edp; edp = (Edrvparam *)BIOSXCHG; memset(edp, 0, sizeof *edp); edp->size = sizeof *edp; edp->dpilen = 36; memset(®s, 0, sizeof regs); if (biosdiskcall(®s, Biosedrvparam, 0, bdp->id, PADDR(edp)) < 0) return 0; /* old bios without extensions */ if(Debug) { print("extgetsize: drive 0x%ux info flags 0x%ux", bdp->id, edp->flags); if (edp->key == 0xbedd) print(" %.4s %.8s", edp->bustype, edp->ifctype); print("\n"); } if (edp->sectsz <= 0) { print("extgetsize: drive 0x%ux: non-positive sector size\n", bdp->id); edp->sectsz = 1; /* don't divide by zero */ } bdp->sectsz = edp->sectsz; return edp->physsects * edp->sectsz;} longbiosread(Fs *fs, void *a, long n){ int want, got, part; long totnr, stuck; Devbytes offset; Biosdev *bdp; if(fs->dev > bdrive.ndevs) return -1; if (n <= 0) return n; bdp = &bdev[fs->dev]; offset = bdp->offset; stuck = 0; for (totnr = 0; totnr < n && stuck < 4; totnr += got) { if (bdp->sectsz == 0) { print("devbios: zero sector size\n"); return -1; } want = bdp->sectsz; if (totnr + want > n) want = n - totnr; if(0 && Debug && debugload) print("bios%d, read: %ld @ off %lld, want: %d, id: 0x%ux\n", fs->dev, n, offset, want, bdp->id); part = offset % bdp->sectsz; if (part != 0) { /* back up to start of sector */ offset -= part; totnr -= part; if (totnr < 0) { print("biosread: negative count %ld\n", totnr); return -1; } } if ((vlong)offset < 0) { print("biosread: negative offset %lld\n", offset); return -1; } got = sectread(bdp, (char *)a + totnr, want, offset/bdp->sectsz); if(got <= 0){// print("biosread: failed to read %ld @ off %lld of 0x%ux, "// "want %d got %d\n",// n, offset, bdp->id, want, got); return -1; } offset += got; bdp->offset = offset; if (got < bdp->sectsz) stuck++; /* we'll have to re-read this sector */ else stuck = 0; } return totnr;} vlongbiosseek(Fs *fs, vlong off){ if (off < 0) { print("biosseek(fs, %lld) is illegal\n", off); return -1; } if(fs->dev > bdrive.ndevs) { print("biosseek: fs->dev %d > bdrive.ndevs %d\n", fs->dev, bdrive.ndevs); return -1; } bdev[fs->dev].offset = off; /* do not know size... (yet) */ return off;} void *biosgetfspart(int i, char *name, int chatty){ static Fs fs; if(strcmp(name, "9fat") != 0){ if(chatty) print("unknown partition bios%d!%s (use bios%d!9fat)\n", i, name, i);Lines 1–500 of 515. Load more
/* * boot driver for BIOS LBA devices * heavily dependent upon correct BIOS implementation */ #include <u.h> #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" #include "ureg.h" #include "fs.h" typedef uvlong Devbytes, Devsects; typedef struct Biosdrive Biosdrive; /* 1 drive -> ndevs */ typedef struct Biosdev Biosdev; enum { Debug = 0, Maxdevs = 8, CF = 1, /* carry flag: indicates an error */ Flopid = 0, /* first floppy */ Baseid = 0x80, /* first disk */ Dap = 1<<0, Edd = 1<<2, /* bios calls: int 0x13 disk services */ Biosinit = 0, /* initialise disk & floppy ctlrs */ Biosdrvsts, Bioschsrdsects, Biosdrvparam = 8, Biosctlrinit, Biosreset = 0xd, /* reset disk */ Biosdrvrdy = 0x10, Biosdrvtype = 0x15, Biosckext = 0x41, Biosrdsect, Biosedrvparam = 0x48, /* disk types */ Typenone = 0, Typedisk = 3, }; struct Biosdrive { int ndevs; }; struct Biosdev { Devbytes size; Devbytes offset; uchar id; /* drive number; e.g., 0x80 */ char type; ushort sectsz; }; typedef struct Extread { /* a device address packet */ uchar size; uchar unused1; uchar nsects; uchar unused2; ulong addr; /* segment:offset; ea = (segment<<4)+offset */ uvlong stsect; /* starting sector */ } Extread; typedef struct Edrvparam { /* from edd 1.1 spec */ ushort size; /* max. buffer size */ ushort flags; ulong physcyls; ulong physheads; ulong phystracksects; uvlong physsects; ushort sectsz; void *dpte; /* ~0ull: invalid */ /* remainder from edd 3.0 spec */ ushort key; /* 0xbedd if present */ uchar dpilen; uchar unused1; ushort unused2; char bustype[4]; /* "PCI" or "ISA" */ char ifctype[8]; /* "ATA", "ATAPI", "SCSI", "USB", "1394", "FIBRE" */ uvlong ifcpath; uvlong devpath; uchar unused3; uchar dpicksum; } Edrvparam; void realmode(int intr, Ureg *ureg); /* from trap.c */ int onlybios0; int biosinited; static Biosdev bdev[Maxdevs]; static Biosdrive bdrive; static Ureg regs; static int dreset(uchar drive); static Devbytes extgetsize(Biosdev *); static Devsects getsize(uchar drive, char *type); static int islba(uchar drive); /* * caller must zero or otherwise initialise *rp, * other than ax, bx, dx, si & ds. */ static int biosdiskcall(Ureg *rp, uchar op, ulong bx, ulong dx, ulong si) { rp->ax = op << 8; rp->bx = bx; rp->dx = dx; /* often drive id */ /* * ensure that addr fits in a short, * then jigger it and DS to avoid segment 0. */ if((si & 0xffff0000) != 0) print("biosdiskcall: address %#lux not a short\n", si); rp->ds = si >> 4; si &= 0xf; if((si & 0xffff0000) != ((si + 512 - 1) & 0xffff0000)) print("biosdiskcall: address %#lux too near segment boundary\n", si); rp->si = si; /* ds:si forms data access packet addr */ /* * *rp is copied into low memory (realmoderegs) and thence into * the machine registers before the BIOS call, and the registers are * copied into realmoderegs and thence into *rp after. */ realmode(0x13, rp); if (rp->flags & CF) { if (Debug && dx == Baseid) print("\nbiosdiskcall: int 0x13 op 0x%ux drive 0x%lux " "failed, ah error code 0x%ux\n", op, dx, (uchar)(rp->ax >> 8)); return -1; } return 0; } /* * Find out what the bios knows about devices. * our boot device could be usb; ghod only knows where it will appear. */ int biosinit(void) { int devid, lba, mask, lastbit; Devbytes size; char type; Biosdev *bdp; static int beenhere; /* 9pxeload can't use bios int 13 calls; they wedge the machine */ if (pxe || !biosload || onlybios0 || biosinited || beenhere) return 0; beenhere = 1; mask = lastbit = 0; for (devid = Baseid; devid < (1 << 8) && bdrive.ndevs < Maxdevs; devid++) { lba = islba(devid); if (lba < 0) break; /* don't reset; it seems to hang the bios */ if(!lba /* || devid != Baseid && dreset(devid) < 0 */ ) continue; type = Typenone; if (getsize(devid, &type) == 0) { /* no device, end of range */ // devid &= ~0xf; // devid += 0x10; // devid--; // break; continue; } lastbit = 1 << bdrive.ndevs; mask |= lastbit; bdp = &bdev[bdrive.ndevs]; bdp->id = devid; bdp->type = type; size = extgetsize(bdp); bdp->size = size; print("bios%d: drive 0x%ux: %,llud bytes, type %d\n", bdrive.ndevs, devid, size, type); bdrive.ndevs++; } USED(lastbit); // islba(Baseid); /* do a successful operation to make bios happy again */ /* * some bioses seem to only be able to read from drive number 0x80 * and certainly can't read from the highest drive number when we * call them, even if there is only one. attempting to read from the * last drive number may yield a hung machine or a two-minute pause. */ if (bdrive.ndevs > 0) { #ifdef NOT_LAST_DRIVE if (bdrive.ndevs == 1) { print("biosinit: sorry, only one bios drive; " "can't read last one\n"); onlybios0 = 1; } else biosinited = 1; bdrive.ndevs--; /* omit last drive number; it can't be read */ mask &= ~lastbit; #else biosinited = 1; #endif } return mask; } void biosinitdev(int i, char *name) { if(i >= bdrive.ndevs) panic("biosinitdev"); sprint(name, "bios%d", i); } void biosprintdevs(int i) { if(i >= bdrive.ndevs){ print("got a print for %d, only got %d\n", i, bdrive.ndevs); panic("biosprintdevs"); } print(" bios%d", i); } int biosboot(int dev, char *file, Boot *b) { Fs *fs; if(strncmp(file, "dos!", 4) == 0) file += 4; if(strchr(file, '!') != nil || strcmp(file, "") == 0) { print("syntax is bios0!file\n"); return -1; } fs = biosgetfspart(dev, "9fat", 1); if(fs == nil) return -1; return fsboot(fs, file, b); } static void dump(void *addr, int wds) { unsigned i; ulong *p = addr; for (i = 0; i < wds; i++) print("%lux ", p[i]); if (i % 8 == 7) print("\n"); print("\n"); } /* read n bytes at sector offset into a from drive id */ long sectread(Biosdev *bdp, void *a, long n, Devsects offset) { uchar *biosparam, *cp; Extread *erp; if(n < 0 || n > bdp->sectsz) return -1; if(Debug) /* scribble on the buffer to provoke trouble */ memset((uchar *)BIOSXCHG, 'r', bdp->sectsz); // if(Debug) // print("drive ready %#ux...", bdp->id); // memset(®s, 0, sizeof regs); // if (biosdiskcall(®s, Biosdrvrdy, 0, bdp->id, 0) < 0) // print("not ready\n"); /* space for a big, optical-size sector, just in case... */ biosparam = (uchar *)BIOSXCHG + 2*1024; /* read into BIOSXCHG */ erp = (Extread *)biosparam; memset(erp, 0, sizeof *erp); erp->size = sizeof *erp; erp->nsects = 1; erp->addr = PADDR(BIOSXCHG); erp->stsect = offset; /* * ensure that addr fits in a short, * then jigger it to avoid segment 0. */ if((erp->addr & 0xffff0000) != 0) print("sectread: address %#lux not a short\n", erp->addr); erp->addr = ((erp->addr & 0xffff) >> 4) << 16 | (erp->addr & 0xf); if((erp->addr & 0xffff0000) != ((erp->addr + 512 - 1) & 0xffff0000)) print("sectread: address %#lux too near segment boundary\n", erp->addr); if (0 && Debug) print("reading drive %#ux offset %lld into seg:off %lux:%ux...", bdp->id, offset, erp->addr>>16, (ushort)erp->addr); if (Debug) dump(erp, sizeof *erp / 4); memset(®s, 0, sizeof regs); regs.es = erp->addr >> 16; if (biosdiskcall(®s, Biosrdsect, (ushort)erp->addr, bdp->id, PADDR(erp)) < 0) { print("sectread: bios failed to read %ld @ sector %lld of 0x%ux\n", n, offset, bdp->id); return -1; } /* copy into caller's buffer */ memmove(a, (char *)BIOSXCHG, n); if(0 && Debug){ cp = (uchar *)BIOSXCHG; print("-%ux %ux %ux %ux--%16.16s-\n", cp[0], cp[1], cp[2], cp[3], (char *)cp + 480); } return n; } /* not tested yet. */ static int dreset(uchar drive) { print("devbios: resetting %#ux...", drive); memset(®s, 0, sizeof regs); if (biosdiskcall(®s, Biosinit, 0, drive, 0) < 0) print("failed"); print("\n"); return regs.ax? -1: 0; /* ax!=0 on error */ } static int islba(uchar drive) { memset(®s, 0, sizeof regs); if (biosdiskcall(®s, Biosckext, 0x55aa, drive, 0) < 0) { /* * we have an old bios without extensions, in theory. * in practice, there may just be no drive for this number. */ // print("islba: drive %ux: Biosckext failed\n", drive); return -1; } if(regs.bx != 0xaa55){ print("islba: buggy bios: drive %#ux extension check returned " "%lux in bx\n", drive, regs.bx); return -1; } if (Debug) print("islba: drive 0x%ux extensions version %d.%d cx 0x%lux\n", drive, (uchar)(regs.ax >> 8), (uchar)regs.ax, regs.cx); /* cx has Edd, Dap bits */ return regs.cx & Dap; } /* * works so so... some floppies are 0x80+x when they shouldn't be, * and report lba even if they cannot... */ static Devsects getsize(uchar id, char *typep) { int dtype; memset(®s, 0, sizeof regs); if (biosdiskcall(®s, Biosdrvtype, 0x55aa, id, 0) < 0) return 0; dtype = (ushort)regs.ax >> 8; *typep = dtype; if(dtype == Typenone){ print("no such device 0x%ux of type %d\n", id, dtype); return 0; } if(dtype != Typedisk){ print("non-disk device 0x%ux of type %d\n", id, dtype); return 0; } return (ushort)regs.cx | regs.dx << 16; } /* extended get size */ static Devbytes extgetsize(Biosdev *bdp) { Edrvparam *edp; edp = (Edrvparam *)BIOSXCHG; memset(edp, 0, sizeof *edp); edp->size = sizeof *edp; edp->dpilen = 36; memset(®s, 0, sizeof regs); if (biosdiskcall(®s, Biosedrvparam, 0, bdp->id, PADDR(edp)) < 0) return 0; /* old bios without extensions */ if(Debug) { print("extgetsize: drive 0x%ux info flags 0x%ux", bdp->id, edp->flags); if (edp->key == 0xbedd) print(" %.4s %.8s", edp->bustype, edp->ifctype); print("\n"); } if (edp->sectsz <= 0) { print("extgetsize: drive 0x%ux: non-positive sector size\n", bdp->id); edp->sectsz = 1; /* don't divide by zero */ } bdp->sectsz = edp->sectsz; return edp->physsects * edp->sectsz; } long biosread(Fs *fs, void *a, long n) { int want, got, part; long totnr, stuck; Devbytes offset; Biosdev *bdp; if(fs->dev > bdrive.ndevs) return -1; if (n <= 0) return n; bdp = &bdev[fs->dev]; offset = bdp->offset; stuck = 0; for (totnr = 0; totnr < n && stuck < 4; totnr += got) { if (bdp->sectsz == 0) { print("devbios: zero sector size\n"); return -1; } want = bdp->sectsz; if (totnr + want > n) want = n - totnr; if(0 && Debug && debugload) print("bios%d, read: %ld @ off %lld, want: %d, id: 0x%ux\n", fs->dev, n, offset, want, bdp->id); part = offset % bdp->sectsz; if (part != 0) { /* back up to start of sector */ offset -= part; totnr -= part; if (totnr < 0) { print("biosread: negative count %ld\n", totnr); return -1; } } if ((vlong)offset < 0) { print("biosread: negative offset %lld\n", offset); return -1; } got = sectread(bdp, (char *)a + totnr, want, offset/bdp->sectsz); if(got <= 0){ // print("biosread: failed to read %ld @ off %lld of 0x%ux, " // "want %d got %d\n", // n, offset, bdp->id, want, got); return -1; } offset += got; bdp->offset = offset; if (got < bdp->sectsz) stuck++; /* we'll have to re-read this sector */ else stuck = 0; } return totnr; } vlong biosseek(Fs *fs, vlong off) { if (off < 0) { print("biosseek(fs, %lld) is illegal\n", off); return -1; } if(fs->dev > bdrive.ndevs) { print("biosseek: fs->dev %d > bdrive.ndevs %d\n", fs->dev, bdrive.ndevs); return -1; } bdev[fs->dev].offset = off; /* do not know size... (yet) */ return off; } void * biosgetfspart(int i, char *name, int chatty) { static Fs fs; if(strcmp(name, "9fat") != 0){ if(chatty) print("unknown partition bios%d!%s (use bios%d!9fat)\n", i, name, i);