Index: conf/i386-pc.rmk
===================================================================
--- conf/i386-pc.rmk (revision 2201)
+++ conf/i386-pc.rmk (working copy)
@@ -185,8 +185,15 @@
aout.mod bsd.mod pxe.mod pxecmd.mod datetime.mod date.mod \
datehook.mod lsmmap.mod ata_pthru.mod hdparm.mod \
usb.mod uhci.mod ohci.mod usbtest.mod usbms.mod usb_keyboard.mod \
- efiemu.mod mmap.mod acpi.mod
+ efiemu.mod mmap.mod acpi.mod drivemap.mod
+# For drivemap.mod.
+drivemap_mod_SOURCES = commands/i386/pc/drivemap.c \
+ commands/i386/pc/drivemap_int13h.S
+drivemap_mod_ASFLAGS = $(COMMON_ASFLAGS)
+drivemap_mod_CFLAGS = $(COMMON_CFLAGS)
+drivemap_mod_LDFLAGS = $(COMMON_LDFLAGS)
+
# For efiemu.mod.
efiemu_mod_SOURCES = efiemu/main.c efiemu/i386/loadcore32.c \
efiemu/i386/loadcore64.c efiemu/i386/pc/cfgtables.c \
Index: commands/i386/pc/drivemap.c
===================================================================
--- commands/i386/pc/drivemap.c (revision 0)
+++ commands/i386/pc/drivemap.c (revision 0)
@@ -0,0 +1,443 @@
+/* drivemap.c - command to manage the BIOS drive mappings. */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see .
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+
+#define MODNAME "drivemap"
+
+static grub_extcmd_t cmd_reghandle;
+
+/* Remember to update enum opt_idxs accordingly. */
+static const struct grub_arg_option options[] = {
+ {"list", 'l', 0, "show the current mappings", 0, 0},
+ {"reset", 'r', 0, "reset all mappings to the default values", 0, 0},
+ {"swap", 's', 0, "perform both direct and reverse mappings", 0, 0},
+ {0, 0, 0, 0, 0, 0}
+};
+
+/* Remember to update options[] accordingly. */
+enum opt_idxs
+{
+ OPTIDX_LIST = 0,
+ OPTIDX_RESET,
+ OPTIDX_SWAP,
+};
+
+/* Realmode far ptr (2 * 16b) to the previous INT13h handler. */
+extern grub_uint32_t grub_drivemap_int13_oldhandler;
+
+/* The type "void" is used for imported assembly labels, takes no storage and
+ serves just to take the address with &label. Do NOT put void* here. */
+/* Start of the handler bundle. */
+extern const void grub_drivemap_int13_handler_base;
+/* Start of the drive mappings area (space reserved at runtime). */
+extern const void grub_drivemap_int13_mapstart;
+/* The assembly function to replace the old INT13h handler. It should not be
+ called because it does not follow any C callspecs and returns with IRET. */
+extern const void grub_drivemap_int13_handler;
+
+typedef struct drivemap_node
+{
+ struct drivemap_node *next;
+ grub_uint8_t newdrive;
+ grub_uint8_t redirto;
+} drivemap_node_t;
+
+static drivemap_node_t *map_head;
+static void *insthandler_hook;
+static int handlermem_hnd;
+static grub_err_t install_int13_handler (int noret __attribute__ ((unused)));
+static grub_err_t uninstall_int13_handler (void);
+
+/* Puts the specified mapping into the table, replacing an existing mapping
+ for newdrive or adding a new one if required. */
+static grub_err_t
+drivemap_set (grub_uint8_t newdrive, grub_uint8_t redirto)
+{
+ drivemap_node_t *mapping = 0;
+ drivemap_node_t *search = map_head;
+ while (search)
+ {
+ if (search->newdrive == newdrive)
+ {
+ mapping = search;
+ break;
+ }
+ search = search->next;
+ }
+
+ /* Check for pre-existing mappings to modify before creating a new one. */
+ if (mapping)
+ mapping->redirto = redirto;
+ else
+ {
+ mapping = grub_malloc (sizeof (drivemap_node_t));
+ if (! mapping)
+ return grub_error (GRUB_ERR_OUT_OF_MEMORY,
+ "cannot allocate map entry, not enough memory");
+ mapping->newdrive = newdrive;
+ mapping->redirto = redirto;
+ mapping->next = map_head;
+ map_head = mapping;
+ }
+ return GRUB_ERR_NONE;
+}
+
+/* Removes the mapping for newdrive from the table. If there is no mapping,
+ then this function behaves like a no-op on the map. */
+static void
+drivemap_remove (grub_uint8_t newdrive)
+{
+ drivemap_node_t *mapping = 0;
+ drivemap_node_t *search = map_head;
+ drivemap_node_t *previous = 0;
+
+ while (search)
+ {
+ if (search->newdrive == newdrive)
+ {
+ mapping = search;
+ break;
+ }
+ previous = search;
+ search = search->next;
+ }
+
+ if (mapping)
+ {
+ if (previous)
+ previous->next = mapping->next;
+ else
+ map_head = mapping->next;
+ grub_free (mapping);
+ }
+}
+
+/* Given a device name, resolves its BIOS disk number and stores it in the
+ passed location, which should only be trusted if ERR_NONE is returned. */
+static grub_err_t
+parse_biosdisk (const char *name, grub_uint8_t * disknum)
+{
+ grub_disk_t disk;
+ /* Skip the first ( in (hd0) - disk_open wants just the name. */
+ if (*name == '(')
+ name++;
+
+ disk = grub_disk_open (name);
+ if (! disk)
+ return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "unknown device \"%s\"", name);
+ const enum grub_disk_dev_id id = disk->dev->id;
+ /* The following assignment is only sound if the device is indeed a
+ biosdisk. The caller must check the return value. */
+ if (disknum)
+ *disknum = disk->id;
+ grub_disk_close (disk);
+ if (id != GRUB_DISK_DEVICE_BIOSDISK_ID)
+ return grub_error (GRUB_ERR_BAD_DEVICE, "%s is not a BIOS disk", name);
+ return GRUB_ERR_NONE;
+}
+
+/* Given a BIOS disk number, returns its GRUB device name if it exists.
+ If the call succeeds, the resulting device string must be freed.
+ For nonexisting BIOS disk numbers, this function returns
+ GRUB_ERR_UNKNOWN_DEVICE. */
+static grub_err_t
+revparse_biosdisk (const grub_uint8_t dnum, const char **output)
+{
+ int found = 0;
+ auto int find (const char *name);
+ int find (const char *name)
+ {
+ const grub_disk_t disk = grub_disk_open (name);
+ if (! disk)
+ return 0;
+ if (disk->id == dnum && disk->dev->id == GRUB_DISK_DEVICE_BIOSDISK_ID)
+ {
+ found = 1;
+ if (output)
+ *output = grub_strdup (name);
+ }
+ grub_disk_close (disk);
+ return found;
+ }
+
+ grub_disk_dev_iterate (find);
+ if (found)
+ return GRUB_ERR_NONE;
+ return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "BIOS disk %02x not found", dnum);
+}
+
+/* Given a GRUB-like device name and a convenient location, stores the
+ related BIOS disk number. Accepts devices like \((f|h)dN\), with
+ 0 <= N < 128. */
+static grub_err_t
+tryparse_diskstring (const char *str, grub_uint8_t * output)
+{
+ /* Skip opening paren in order to allow both (hd0) and hd0. */
+ if (*str == '(')
+ str++;
+ if ((str[0] == 'f' || str[0] == 'h') && str[1] == 'd')
+ {
+ grub_uint8_t bios_num = (str[0] == 'h') ? 0x80 : 0x00;
+ unsigned long drivenum = grub_strtoul (str + 2, 0, 0);
+ if (grub_errno == GRUB_ERR_NONE && drivenum < 128)
+ {
+ bios_num |= drivenum;
+ if (output)
+ *output = bios_num;
+ return GRUB_ERR_NONE;
+ }
+ }
+ return grub_error (GRUB_ERR_BAD_ARGUMENT, "device format \"%s\" "
+ "invalid: must be (f|h)dN, with 0 <= N < 128", str);
+}
+
+static grub_err_t
+grub_cmd_drivemap (struct grub_extcmd *cmd, int argc, char **args)
+{
+ if (cmd->state[OPTIDX_LIST].set || argc == 0)
+ {
+ /* Show: list mappings. */
+ if (! map_head)
+ {
+ grub_printf ("No drives have been remapped");
+ return GRUB_ERR_NONE;
+ }
+ grub_printf ("Showing only remapped drives.\n");
+ grub_printf ("BIOS disk #num ----> GRUB device\n");
+ drivemap_node_t *curnode = map_head;
+ while (curnode)
+ {
+ const char *dname = 0;
+ grub_err_t err = revparse_biosdisk (curnode->redirto, &dname);
+ if (err != GRUB_ERR_NONE)
+ return err;
+ grub_printf ("%cD #%-3u (0x%02x) %s\n",
+ (curnode->newdrive & 0x80) ? 'H' : 'F',
+ curnode->newdrive & 0x7F, curnode->newdrive,
+ dname);
+ curnode = curnode->next;
+ grub_free ((char *) dname);
+ }
+ return GRUB_ERR_NONE;
+ }
+ else if (cmd->state[OPTIDX_RESET].set)
+ {
+ /* Reset: just delete all mappings, freeing their memory. */
+ drivemap_node_t *curnode = map_head;
+ drivemap_node_t *prevnode = 0;
+ while (curnode)
+ {
+ prevnode = curnode;
+ curnode = curnode->next;
+ grub_free (prevnode);
+ }
+ map_head = 0;
+ return GRUB_ERR_NONE;
+ }
+
+ /* Neither flag: put mapping. */
+ grub_uint8_t mapfrom = 0;
+ grub_uint8_t mapto = 0xFF;
+ grub_err_t err;
+
+ if (argc != 2)
+ return grub_error (GRUB_ERR_BAD_ARGUMENT, "two arguments required");
+
+ err = parse_biosdisk (args[0], &mapfrom);
+ if (err != GRUB_ERR_NONE)
+ return err;
+
+ /* When swapping we require both devices to be BIOS disks, but when
+ performing direct mappings we only require the 2nd argument to look
+ like a BIOS disk in order to resolve it into a BIOS disk number. */
+ if (cmd->state[OPTIDX_SWAP].set)
+ err = parse_biosdisk (args[1], &mapto);
+ else
+ err = tryparse_diskstring (args[1], &mapto);
+ if (err != GRUB_ERR_NONE)
+ return err;
+
+ if (mapto == mapfrom)
+ {
+ /* Reset to default. */
+ grub_dprintf (MODNAME, "Removing the mapping for %s (%02x)",
+ args[0], mapfrom);
+ drivemap_remove (mapfrom);
+ return GRUB_ERR_NONE;
+ }
+ /* Set the mapping for the disk (overwrites any existing mapping). */
+ grub_dprintf (MODNAME, "%s %s (%02x) = %s (%02x)\n",
+ cmd->state[OPTIDX_SWAP].set ? "Swapping" : "Mapping",
+ args[1], mapto, args[0], mapfrom);
+ err = drivemap_set (mapto, mapfrom);
+ /* If -s, perform the reverse mapping too (only if the first was OK). */
+ if (cmd->state[OPTIDX_SWAP].set && err == GRUB_ERR_NONE)
+ err = drivemap_set (mapfrom, mapto);
+ return err;
+}
+
+typedef struct __attribute__ ((packed)) int13map_node
+{
+ grub_uint8_t disknum;
+ grub_uint8_t mapto;
+} int13map_node_t;
+
+#define INT13H_OFFSET(x) ( ((grub_uint8_t*)(x)) - ((grub_uint8_t*)&grub_drivemap_int13_handler_base) )
+#define INT13H_REBASE(x) ( (void*) (handler_base + (x)) )
+#define INT13H_TONEWADDR(x) INT13H_REBASE( INT13H_OFFSET( x ) )
+
+/* Int13h handler installer - reserves conventional memory for the handler,
+ copies it over and sets the IVT entry for int13h.
+ This code rests on the assumption that GRUB does not activate any kind
+ of memory mapping apart from identity paging, since it accesses
+ realmode structures by their absolute addresses, like the IVT at 0;
+ and transforms a pmode pointer into a rmode seg:off far ptr. */
+static grub_err_t
+install_int13_handler (int noret __attribute__ ((unused)))
+{
+ grub_size_t entries = 0;
+ drivemap_node_t *curentry = map_head;
+
+ /* Count entries to prepare a contiguous map block. */
+ while (curentry)
+ {
+ entries++;
+ curentry = curentry->next;
+ }
+ if (entries == 0)
+ {
+ /* No need to install the int13h handler. */
+ grub_dprintf (MODNAME, "No drives marked as remapped, installation "
+ "of an int13h handler is not required.");
+ return GRUB_ERR_NONE;
+ }
+ else
+ {
+ /* Real mode IVT slot (seg:off far pointer) for interrupt 0x13. */
+ grub_uint32_t *ivtslot = UINT_TO_PTR (0x0000004c);
+ /* Size of the full int13 handler "bundle", including code and map. */
+ grub_uint64_t total_size;
+ /* Base address of the space reserved for the handler bundle. */
+ grub_uint8_t *handler_base = 0;
+ /* Address of the map within the deployed bundle. */
+ int13map_node_t *handler_map;
+ /* Real mode IVT entry (seg:off far pointer) for the new handler. */
+ grub_uint32_t ivtentry;
+
+ grub_dprintf (MODNAME, "Installing int13h handler...\n");
+
+ /* Save the pointer to the old handler. */
+ grub_drivemap_int13_oldhandler = *ivtslot;
+ grub_dprintf (MODNAME, "Old int13 handler at %04x:%04x\n",
+ (grub_drivemap_int13_oldhandler >> 16) & 0x0ffff,
+ grub_drivemap_int13_oldhandler & 0x0ffff);
+
+ /* Find a rmode-segment-aligned zone in conventional memory big
+ enough to hold the handler and its data. */
+ total_size = INT13H_OFFSET(&grub_drivemap_int13_mapstart)
+ + (entries + 1) * sizeof (int13map_node_t);
+ grub_dprintf (MODNAME, "Payload is %llu bytes long\n", total_size);
+ handler_base = grub_mmap_malign_and_register (16, total_size,
+ &handlermem_hnd,
+ GRUB_MACHINE_MEMORY_RESERVED,
+ GRUB_MMAP_MALLOC_LOW);
+ if (! handler_base)
+ return grub_error (GRUB_ERR_OUT_OF_MEMORY, "Could not reserve "
+ "memory for the int13h handler");
+
+ /* Copy int13h handler bundle to reserved area. */
+ grub_dprintf (MODNAME, "Reserved memory at %p, copying handler...\n",
+ handler_base);
+ grub_memcpy (handler_base, &grub_drivemap_int13_handler_base,
+ INT13H_OFFSET (&grub_drivemap_int13_mapstart));
+
+ /* Copy the mappings to the reserved area. */
+ curentry = map_head;
+ grub_size_t i;
+ handler_map = INT13H_TONEWADDR (&grub_drivemap_int13_mapstart);
+ grub_dprintf (MODNAME, "Target map at %p, copying mappings...\n",
+ handler_map);
+ for (i = 0; i < entries; ++i, curentry = curentry->next)
+ {
+ handler_map[i].disknum = curentry->newdrive;
+ handler_map[i].mapto = curentry->redirto;
+ grub_dprintf (MODNAME, "\t#%d: 0x%02x <- 0x%02x\n", i,
+ handler_map[i].disknum, handler_map[i].mapto);
+ }
+ /* Signal end-of-map. */
+ handler_map[i].disknum = 0;
+ handler_map[i].mapto = 0;
+ grub_dprintf (MODNAME, "\t#%d: 0x00 <- 0x00 (end)\n", i);
+
+ /* Install our function as the int13h handler in the IVT. */
+ ivtentry = ((grub_uint32_t) handler_base) << 12; /* Segment address. */
+ ivtentry |=
+ (grub_uint16_t) INT13H_OFFSET (&grub_drivemap_int13_handler);
+ grub_dprintf (MODNAME, "New int13 handler IVT pointer: %04x:%04x\n",
+ (ivtentry >> 16) & 0x0ffff, ivtentry & 0x0ffff);
+ *ivtslot = ivtentry;
+
+ return GRUB_ERR_NONE;
+ }
+}
+
+static grub_err_t
+uninstall_int13_handler (void)
+{
+ grub_uint32_t *ivtslot = UINT_TO_PTR (0x0000004c);
+
+ if (grub_drivemap_int13_oldhandler != 0)
+ return GRUB_ERR_NONE;
+
+ *ivtslot = grub_drivemap_int13_oldhandler;
+ grub_mmap_free_and_unregister (handlermem_hnd);
+ grub_drivemap_int13_oldhandler = 0;
+
+ return GRUB_ERR_NONE;
+}
+
+GRUB_MOD_INIT (drivemap)
+{
+ cmd_reghandle = grub_register_extcmd (MODNAME, grub_cmd_drivemap,
+ GRUB_COMMAND_FLAG_BOTH,
+ MODNAME
+ " -l | -r | [-s] grubdev biosdisk",
+ "Manage the BIOS drive mappings",
+ options);
+ insthandler_hook =
+ grub_loader_register_preboot_hook (&install_int13_handler,
+ &uninstall_int13_handler,
+ GRUB_LOADER_PREBOOT_HOOK_PRIO_NORMAL);
+}
+
+GRUB_MOD_FINI (drivemap)
+{
+ grub_loader_unregister_preboot_hook (insthandler_hook);
+ insthandler_hook = 0;
+ grub_unregister_extcmd (cmd_reghandle);
+}
Index: commands/i386/pc/drivemap_int13h.S
===================================================================
--- commands/i386/pc/drivemap_int13h.S (revision 0)
+++ commands/i386/pc/drivemap_int13h.S (revision 0)
@@ -0,0 +1,70 @@
+/* drivemap_int13h.S - interrupt handler for the BIOS drive remapper */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see .
+ */
+
+#include
+
+#define INT13H_OFFSET(x) ((x) - grub_drivemap_int13_handler_base)
+
+.code16
+
+/* Copy starts here. When deployed, this label must be segment-aligned. */
+VARIABLE(grub_drivemap_int13_handler_base)
+
+/* Far pointer to the old handler. Stored as a CS:IP in the style of real-mode
+ IVT entries (thus PI:SC in mem). */
+VARIABLE(grub_drivemap_int13_oldhandler)
+ .word 0x0, 0x0
+
+/* Actual int13 handler. We use relative addressing with CS in order to be as
+ unintrusive as possible with registers and the stack. */
+FUNCTION(grub_drivemap_int13_handler)
+ /* Map the drive number (always in DL). */
+ push %ax
+ push %bx
+ push %si
+ movw $INT13H_OFFSET(grub_drivemap_int13_mapstart), %bx
+ xorw %si, %si
+
+more_remaining:
+ movw %cs:(%bx,%si), %ax
+ cmpb %ah, %al
+ jz not_found /* DRV=DST => map end - drive not remapped, keep DL. */
+ cmpb %dl, %al
+ jz found /* Found - drive remapped, modify DL. */
+ addw $2, %si
+ jmp more_remaining /* Not found, but more remaining, loop. */
+
+found:
+ movb %ah, %dl
+
+not_found:
+ pop %si
+ pop %bx
+ pop %ax
+
+ /* Upon arrival to this point the stack must be exactly like at entry.
+ This long jump will transfer the caller's stack to the old INT13
+ handler, thus making it return directly to the original caller. */
+ ljmp *%cs:INT13H_OFFSET(grub_drivemap_int13_oldhandler)
+
+
+/* This label MUST be at the end of the copied block, since the installer code
+ reserves additional space for mappings at runtime and copies them over it. */
+.align 2
+VARIABLE(grub_drivemap_int13_mapstart)