November 2020 - flashrom-gerrit

Change in flashrom[master]: fmap: Bring in CrOS get_fmap_entries() verbatim
by Edward O'Callaghan (Code Review) Nov. 1, 2020

Nov. 1, 2020

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/47063 ) Change subject: fmap: Bring in CrOS get_fmap_entries() verbatim ...................................................................... fmap: Bring in CrOS get_fmap_entries() verbatim Change-Id: I0b2372e3473939064515f698b23ad4c0048bb408 Signed-off-by: Edward O'Callaghan <quasisec(a)google.com> --- M fmap.c M fmap.h 2 files changed, 314 insertions(+), 0 deletions(-) git pull ssh://review.coreboot.org:29418/flashrom refs/changes/63/47063/1 diff --git a/fmap.c b/fmap.c index 2f34a5c..b3d8542 100644 --- a/fmap.c +++ b/fmap.c @@ -38,8 +38,15 @@ #include <stdlib.h> #include <string.h> #include <sys/types.h> +#include <arpa/inet.h> + #include "flash.h" #include "fmap.h" +#include "layout.h" +#include "search.h" + +#define ACPI_FMAP_PATH "/sys/devices/platform/chromeos_acpi/FMAP" +#define FDT_FMAP_PATH "/proc/device-tree/firmware/chromeos/fmap-offset" static size_t fmap_size(const struct fmap *fmap) { @@ -146,6 +153,14 @@ return 0; } +int fmap_find(struct fmap *fmap) +{ + if (!is_valid_fmap(fmap)) + return 0; + + return fmap_size(fmap); +} + static int fmap_lsearch_rom(struct fmap **fmap_out, struct flashctx *const flashctx, size_t rom_offset, size_t len) { @@ -329,3 +344,301 @@ return ret; } + +/* Read value from ACPI in sysfs, if it exists. */ +__attribute__((unused)) static int read_fmap_base_acpi(uint32_t *out) +{ + int rv = 0; + FILE *f; + + if (!(f = fopen(ACPI_FMAP_PATH, "r"))) + return -1; + + /* FMAP base is an ASCII signed integer. */ + if (fscanf(f, "%d", (int *)out) != 1) + rv = -1; + + fclose(f); + + if (rv) + msg_gdbg("%s: failed to read fmap_base from ACPI\n", __func__); + else + msg_gdbg("%s: read fmap_base from ACPI\n", __func__); + + return rv; +} + +/* Read value from FDT, if it exists. */ +__attribute__((unused)) static int read_fmap_base_fdt(uint32_t *out) +{ + int rv = 0; + uint32_t data; + FILE *f; + + if (!(f = fopen(FDT_FMAP_PATH, "r"))) + return -1; + + /* Value is stored as network-byte order dword. */ + if (fread(&data, sizeof(data), 1, f) != 1) + rv = -1; + else + *out = ntohl(data); + + fclose(f); + + if (rv) + msg_gdbg("%s: failed to read fmap_base from FDT\n", __func__); + else + msg_gdbg("%s: read fmap_base from FDT\n", __func__); + + return rv; +} + +/* + * Find the FMAP base from ACPI or FDT. + * @search: Search information + * @offset: Place to put offset + * @return 0 if offset found, -1 if not + */ +static int get_fmap_base(struct search_info *search, off_t *offset) +{ + uint32_t fmap_base; + uint32_t from_top; + +#if IS_X86 + if (read_fmap_base_acpi(&fmap_base) < 0) + return -1; +#elif IS_ARM + if (read_fmap_base_fdt(&fmap_base) < 0) + return -1; +#else + return -1; +#endif + + /* + * TODO(b/158017386): see if we can remove this hack. It may + * only apply to older platforms which are now AUE. + * + * There are 2 kinds of fmap_base. + * + * 1. Shadow ROM/BIOS area (x86), such as 0xFFxxxxxx. + * 2. Offset to start of flash, such as 0x00xxxxxx. + * + * The shadow ROM is a cached copy of the BIOS ROM which resides below + * 4GB host/CPU memory address space on x86. The top of BIOS address + * aligns to the last byte of address space, 0xFFFFFFFF. So to obtain + * the ROM offset when shadow ROM is used, we subtract the fmap_base + * from 4G minus 1. + * + * CPU address flash address + * space p space + * 0xFFFFFFFF +-------+ --- +-------+ 0x400000 + * | | ^ | | ^ + * | 4MB | | | | | from_top + * | | v | | v + * fmap_base--> | -fmap | ------|--fmap-|-- the offset we need. + * ^ | | | | + * | +-------+-------+-------+ 0x000000 + * | | | + * | | | + * | | | + * | | | + * 0x00000000 +-------+ + * + * We'll use bit 31 to determine if the shadow BIOS area is being used. + * This is sort of a hack, but allows us to perform sanity checking for + * older x86-based Chrome OS platforms. + */ + + msg_gdbg("%s: fmap_base: %#x, ROM size: 0x%zx\n", + __func__, fmap_base, search->total_size); + + if (fmap_base & (1 << 31)) { + from_top = 0xFFFFFFFF - fmap_base + 1; + msg_gdbg("%s: fmap is located in shadow ROM, from_top: %#x\n", + __func__, from_top); + if (from_top > search->total_size) + return -1; + *offset = search->total_size - from_top; + } else { + msg_gdbg("%s: fmap is located in physical ROM\n", __func__); + if (fmap_base > search->total_size) + return -1; + *offset = fmap_base; + } + + msg_gdbg("%s: ROM offset: %#jx\n", __func__, (intmax_t)*offset); + return 0; +} + +static int add_fmap_entries_from_buf(const uint8_t *buf) +{ + struct fmap *fmap; + int i; + struct flashrom_layout *const layout = get_global_layout(); + + fmap = (struct fmap *)(buf); + + for (i = 0; i < fmap->nareas; i++) { + if (layout->num_entries >= MAX_ROMLAYOUT) { + msg_gerr("ROM image contains too many regions\n"); + return -1; + } + layout->entries[layout->num_entries].start = fmap->areas[i].offset; + + /* + * Flashrom rom entries use absolute addresses. So for non-zero + * length entries, we need to subtract 1 from offset + size to + * determine the end address. + */ + layout->entries[layout->num_entries].end = fmap->areas[i].offset + + fmap->areas[i].size; + if (fmap->areas[i].size) + layout->entries[layout->num_entries].end--; + + size_t name_len = sizeof(fmap->areas[i].name); + layout->entries[layout->num_entries].name = calloc(1, name_len); + memcpy(layout->entries[layout->num_entries].name, fmap->areas[i].name, name_len); + + layout->entries[layout->num_entries].included = 0; + strcpy(layout->entries[layout->num_entries].file, ""); + + msg_gdbg("added fmap region \"%s\" (file=\"%s\") as %sincluded," + " start: 0x%08x, end: 0x%08x\n", + layout->entries[layout->num_entries].name, + layout->entries[layout->num_entries].file, + layout->entries[layout->num_entries].included ? "" : "not ", + layout->entries[layout->num_entries].start, + layout->entries[layout->num_entries].end); + layout->num_entries++; + } + + return layout->num_entries; +} + +enum found_t { + FOUND_NONE, + FOUND_FMAP, +}; + +/* returns the number of entries added, or <0 to indicate error */ +static int add_fmap_entries(void *source_handle, + size_t image_size, + int (*read_chunk)(void *handle, + void *dest, + size_t offset, + size_t size)) +{ + static enum found_t found = FOUND_NONE; + struct search_info search; + struct fmap fmap_header; + uint8_t *buf = NULL; + off_t offset; + struct flashrom_layout *const layout = get_global_layout(); + + if (found != FOUND_NONE) { + msg_gdbg("Already found fmap entries, not searching again.\n"); + return 0; + } + + search_init(&search, source_handle, + image_size, sizeof(fmap_header), read_chunk); + search.handler = get_fmap_base; + while (found == FOUND_NONE && !search_find_next(&search, &offset)) { + if (search.image) { + memcpy(&fmap_header, search.image + offset, + sizeof(fmap_header)); + } else if (read_chunk(source_handle, (uint8_t *)&fmap_header, + offset, sizeof(fmap_header))) { + msg_gdbg("[L%d] failed to read flash at offset %#jx\n", + __LINE__, (intmax_t)offset); + return -1; + } + int buf_size = fmap_find(&fmap_header); + if (buf_size == 0) + continue; + buf = calloc(1, buf_size); + + if (read_chunk(source_handle, buf, offset, buf_size)) { + msg_gdbg("[L%d] failed to read %d bytes at offset 0x%lx\n", + __LINE__, buf_size, (unsigned long)offset); + return -1; + } else { + found = FOUND_FMAP; + } + } + + switch (found) { + case FOUND_FMAP: + layout->num_entries = add_fmap_entries_from_buf(buf); + break; + default: + msg_gdbg("%s: no fmap present\n", __func__); + } + if (buf) + free(buf); + search_free(&search); + + return layout->num_entries; +} + +/* + * read_chunk() callback used when reading contents from a file. + */ +static int read_from_file(void *fhandle, + void *dest, + size_t offset, + size_t size) +{ + FILE *handle = fhandle; + + if (fseek(handle, offset, SEEK_SET)) { + msg_cerr("%s failed to seek to position %zd\n", + __func__, offset); + return 1; + } + + if (fread(dest, 1, size, handle) != size) { + msg_cerr("%s failed to read %zd bytes\n", + __func__, offset); + return 1; + } + + return 0; +} + +/* + * read_chunk() callback used when reading contents from the flash device. + */ +static int read_from_flash(void *handle, + void *dest, + size_t offset, + size_t size) +{ + struct flashctx *flash = handle; + + return read_flash(flash, dest, offset, size); +} + +int get_fmap_entries(const char *filename, struct flashctx *flash) +{ + int rv; + size_t image_size = flash->chip->total_size * 1024; + + /* Let's try retrieving entries from file. */ + if (filename) { + FILE *handle; + + handle = fopen(filename, "r"); + if (handle) { + rv = add_fmap_entries(handle, + image_size, read_from_file); + fclose(handle); + if (rv > 0) + return rv; + msg_cerr("No fmap entries found in %s\n", filename); + } + } + + return add_fmap_entries(flash, image_size, read_from_flash); +} diff --git a/fmap.h b/fmap.h index 924e11f..840de3d 100644 --- a/fmap.h +++ b/fmap.h @@ -67,5 +67,6 @@ int fmap_read_from_buffer(struct fmap **fmap_out, const uint8_t *buf, size_t len); int fmap_read_from_rom(struct fmap **fmap_out, struct flashctx *const flashctx, size_t rom_offset, size_t len); +int get_fmap_entries(const char *filename, struct flashctx *flash); #endif /* __FMAP_H__*/ -- To view, visit https://review.coreboot.org/c/flashrom/+/47063 To unsubscribe, or for help writing mail filters, visit https://review.coreboot.org/settings Gerrit-Project: flashrom Gerrit-Branch: master Gerrit-Change-Id: I0b2372e3473939064515f698b23ad4c0048bb408 Gerrit-Change-Number: 47063 Gerrit-PatchSet: 1 Gerrit-Owner: Edward O'Callaghan <quasisec(a)chromium.org> Gerrit-MessageType: newchange

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Change in flashrom[master]: fmap.c: inline fmap_find()
by Edward O'Callaghan (Code Review) Nov. 1, 2020

Nov. 1, 2020

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/47064 ) Change subject: fmap.c: inline fmap_find() ...................................................................... fmap.c: inline fmap_find() Change-Id: I2925cf62465ea35faf76b8d570eb886091250c07 Signed-off-by: Edward O'Callaghan <quasisec(a)google.com> --- M fmap.c 1 file changed, 2 insertions(+), 10 deletions(-) git pull ssh://review.coreboot.org:29418/flashrom refs/changes/64/47064/1 diff --git a/fmap.c b/fmap.c index b3d8542..8155aa3 100644 --- a/fmap.c +++ b/fmap.c @@ -153,14 +153,6 @@ return 0; } -int fmap_find(struct fmap *fmap) -{ - if (!is_valid_fmap(fmap)) - return 0; - - return fmap_size(fmap); -} - static int fmap_lsearch_rom(struct fmap **fmap_out, struct flashctx *const flashctx, size_t rom_offset, size_t len) { @@ -554,9 +546,9 @@ __LINE__, (intmax_t)offset); return -1; } - int buf_size = fmap_find(&fmap_header); - if (buf_size == 0) + if (!is_valid_fmap(&fmap_header)) continue; + int buf_size = fmap_size(&fmap_header); buf = calloc(1, buf_size); if (read_chunk(source_handle, buf, offset, buf_size)) { -- To view, visit https://review.coreboot.org/c/flashrom/+/47064 To unsubscribe, or for help writing mail filters, visit https://review.coreboot.org/settings Gerrit-Project: flashrom Gerrit-Branch: master Gerrit-Change-Id: I2925cf62465ea35faf76b8d570eb886091250c07 Gerrit-Change-Number: 47064 Gerrit-PatchSet: 1 Gerrit-Owner: Edward O'Callaghan <quasisec(a)chromium.org> Gerrit-MessageType: newchange

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Change in flashrom[master]: fmap.c: Port to upstream
by Edward O'Callaghan (Code Review) Nov. 1, 2020

Nov. 1, 2020

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/47065 ) Change subject: fmap.c: Port to upstream ...................................................................... fmap.c: Port to upstream Change-Id: I489761f531c3a44978f6450cdd0f1ff991f13d87 Signed-off-by: Edward O'Callaghan <quasisec(a)google.com> --- M fmap.c M layout.h 2 files changed, 2 insertions(+), 1 deletion(-) git pull ssh://review.coreboot.org:29418/flashrom refs/changes/65/47065/1 diff --git a/fmap.c b/fmap.c index 8155aa3..fb6e0d3 100644 --- a/fmap.c +++ b/fmap.c @@ -609,7 +609,7 @@ { struct flashctx *flash = handle; - return read_flash(flash, dest, offset, size); + return flash->chip->read(flash, dest, offset, size); } int get_fmap_entries(const char *filename, struct flashctx *flash) diff --git a/layout.h b/layout.h index 8e4eb13..b32d0ca 100644 --- a/layout.h +++ b/layout.h @@ -40,6 +40,7 @@ chipoff_t end; bool included; char *name; + char file[256]; /* file[0]=='\0' means not specified. */ }; struct flashrom_layout { -- To view, visit https://review.coreboot.org/c/flashrom/+/47065 To unsubscribe, or for help writing mail filters, visit https://review.coreboot.org/settings Gerrit-Project: flashrom Gerrit-Branch: master Gerrit-Change-Id: I489761f531c3a44978f6450cdd0f1ff991f13d87 Gerrit-Change-Number: 47065 Gerrit-PatchSet: 1 Gerrit-Owner: Edward O'Callaghan <quasisec(a)chromium.org> Gerrit-MessageType: newchange

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Change in flashrom[master]: cli_classic.c: Attempt to hook up fmap cros feature
by Edward O'Callaghan (Code Review) Nov. 1, 2020

Nov. 1, 2020

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/47066 ) Change subject: cli_classic.c: Attempt to hook up fmap cros feature ...................................................................... cli_classic.c: Attempt to hook up fmap cros feature Change-Id: Ieb8e96821832ed8a4ab6f1525a2b263925c76968 Signed-off-by: Edward O'Callaghan <quasisec(a)google.com> --- M cli_classic.c 1 file changed, 26 insertions(+), 0 deletions(-) git pull ssh://review.coreboot.org:29418/flashrom refs/changes/66/47066/1 diff --git a/cli_classic.c b/cli_classic.c index ae7f6ef..beb578c 100644 --- a/cli_classic.c +++ b/cli_classic.c @@ -154,11 +154,13 @@ int read_it = 0, write_it = 0, erase_it = 0, verify_it = 0; int dont_verify_it = 0, dont_verify_all = 0, list_supported = 0, operation_specified = 0; struct flashrom_layout *layout = NULL; + int set_ignore_fmap = 0; enum programmer prog = PROGRAMMER_INVALID; enum { OPTION_IFD = 0x0100, OPTION_FMAP, OPTION_FMAP_FILE, + OPTION_IGNORE_FMAP, OPTION_FLASH_CONTENTS, OPTION_FLASH_NAME, OPTION_FLASH_SIZE, @@ -187,6 +189,7 @@ {"ifd", 0, NULL, OPTION_IFD}, {"fmap", 0, NULL, OPTION_FMAP}, {"fmap-file", 1, NULL, OPTION_FMAP_FILE}, + {"ignore-fmap", 0, NULL, OPTION_IGNORE_FMAP}, {"image", 1, NULL, 'i'}, {"flash-contents", 1, NULL, OPTION_FLASH_CONTENTS}, {"flash-name", 0, NULL, OPTION_FLASH_NAME}, @@ -314,6 +317,9 @@ cli_classic_abort_usage("Error: --layout and --fmap both specified. Aborting.\n"); fmap = 1; break; + case OPTION_IGNORE_FMAP: + set_ignore_fmap = 1; + break; case 'i': tempstr = strdup(optarg); if (register_include_arg(&include_args, tempstr)) { @@ -641,6 +647,26 @@ goto out_shutdown; } +#if 0 + /* If the user doesn't specify any -i argument, then we can skip the + * fmap parsing to speed up. */ + if (get_num_include_args() == 0 && !extract_it) { + msg_gdbg("No -i argument is specified, set ignore_fmap.\n"); + set_ignore_fmap = 1; + } +#endif + + /* + * Add entries for regions specified in flashmap, unless the user + * explicitly requested not to look for fmap, or provided a layout + * file. + */ + if (!set_ignore_fmap && !layoutfile && + get_fmap_entries(filename, fill_flash) < 0) { + ret = 1; + goto out_shutdown; + } + if (set_wp_enable && set_wp_disable) { msg_ginfo("Error: --wp-enable and --wp-disable are mutually exclusive\n"); ret = 1; -- To view, visit https://review.coreboot.org/c/flashrom/+/47066 To unsubscribe, or for help writing mail filters, visit https://review.coreboot.org/settings Gerrit-Project: flashrom Gerrit-Branch: master Gerrit-Change-Id: Ieb8e96821832ed8a4ab6f1525a2b263925c76968 Gerrit-Change-Number: 47066 Gerrit-PatchSet: 1 Gerrit-Owner: Edward O'Callaghan <quasisec(a)chromium.org> Gerrit-MessageType: newchange

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Change in flashrom[master]: search.c: Fix warnings
by Edward O'Callaghan (Code Review) Nov. 1, 2020

Nov. 1, 2020

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/47062 ) Change subject: search.c: Fix warnings ...................................................................... search.c: Fix warnings Change-Id: I9f5e9e5a799a1d702381d48682b536e6d53331ad Signed-off-by: Edward O'Callaghan <quasisec(a)google.com> --- M search.c 1 file changed, 5 insertions(+), 9 deletions(-) git pull ssh://review.coreboot.org:29418/flashrom refs/changes/62/47062/1 diff --git a/search.c b/search.c index 1a9f197..0801a14 100644 --- a/search.c +++ b/search.c @@ -79,19 +79,16 @@ search->state = SEARCH_STATE_USE_HANDLER; search->stride = search->ceiling_size / 2; search->offset = search->ceiling_size - search->stride; - /* no break */ + /* fallthrough */ case SEARCH_STATE_USE_HANDLER: search->state = SEARCH_STATE_BINARY_SEARCH; search->offset = search->ceiling_size - search->stride; if (search->handler) { ret = search->handler(search, offsetp); - if (!ret && - (*offsetp < - (search->total_size - search->min_size)) && - (*offsetp >= 0)) + if (!ret && ((size_t)*offsetp < (search->total_size - search->min_size)) && (*offsetp >= 0)) return 0; } - /* no break */ + /* fallthrough */ case SEARCH_STATE_BINARY_SEARCH: /* * For efficient operation, we start with the largest stride @@ -127,8 +124,7 @@ if (search->offset < 0) { search->stride /= 2; search->offset = search->ceiling_size - search->stride; - while (search->offset > - (search->total_size - search->min_size)) + while ((size_t)search->offset > (search->total_size - search->min_size)) search->offset -= search->stride; if (search->stride < 16) { search->state = SEARCH_STATE_FULL_SEARCH; @@ -163,7 +159,7 @@ */ do { *offsetp = search->offset--; - } while (*offsetp > search->total_size - search->min_size); + } while ((size_t)*offsetp > search->total_size - search->min_size); if (search->offset < 0) search->state = SEARCH_STATE_DONE; return 0; -- To view, visit https://review.coreboot.org/c/flashrom/+/47062 To unsubscribe, or for help writing mail filters, visit https://review.coreboot.org/settings Gerrit-Project: flashrom Gerrit-Branch: master Gerrit-Change-Id: I9f5e9e5a799a1d702381d48682b536e6d53331ad Gerrit-Change-Number: 47062 Gerrit-PatchSet: 1 Gerrit-Owner: Edward O'Callaghan <quasisec(a)chromium.org> Gerrit-MessageType: newchange

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Change in flashrom[master]: search,Makefile: Import from CrOS verbatim
by Edward O'Callaghan (Code Review) Nov. 1, 2020

Nov. 1, 2020

Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/47061 ) Change subject: search,Makefile: Import from CrOS verbatim ...................................................................... search,Makefile: Import from CrOS verbatim Change-Id: I7e4e90195b7857a4089d79264d471ede9ab79cd1 Signed-off-by: Edward O'Callaghan <quasisec(a)google.com> --- M Makefile A search.c A search.h 3 files changed, 305 insertions(+), 1 deletion(-) git pull ssh://review.coreboot.org:29418/flashrom refs/changes/61/47061/1 diff --git a/Makefile b/Makefile index 225db9d..4f04ae9 100644 --- a/Makefile +++ b/Makefile @@ -643,7 +643,7 @@ ############################################################################### # Library code. -LIB_OBJS = libflashrom.o layout.o flashrom.o udelay.o programmer.o helpers.o ich_descriptors.o fmap.o +LIB_OBJS = libflashrom.o layout.o flashrom.o udelay.o programmer.o helpers.o ich_descriptors.o fmap.o search.o ############################################################################### # Frontend related stuff. diff --git a/search.c b/search.c new file mode 100644 index 0000000..1a9f197 --- /dev/null +++ b/search.c @@ -0,0 +1,198 @@ +/* + * Copyright 2013, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * This is ported from the flashmap utility: http://flashmap.googlecode.com + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <limits.h> + +#include "flash.h" +#include "search.h" + + +/* Ceil a number to the minimum power of 2 value. For example, + * ceiling(2) = 2 + * ceiling(5) = 8 + * ceiling(254K) = 256K + * + * Return -1 if the input value is invalid.. + */ +static long int ceiling(long int v) { + int shiftwidth; + + if (v <= 0) return -1; + + /* it is power of 2. */ + if (!(v & (v - 1))) return v; + + /* pollute all bits below MSB to 1. */ + for (shiftwidth = (sizeof(v) * CHAR_BIT) / 2; + shiftwidth > 0; + shiftwidth /= 2) { + v = v | (v >> shiftwidth); + } + + return v + 1; +} + +int search_find_next(struct search_info *search, off_t *offsetp) +{ + int ret; + + switch (search->state) { + case SEARCH_STATE_START: + search->ceiling_size = ceiling(search->total_size); + search->state = SEARCH_STATE_USE_HANDLER; + search->stride = search->ceiling_size / 2; + search->offset = search->ceiling_size - search->stride; + /* no break */ + case SEARCH_STATE_USE_HANDLER: + search->state = SEARCH_STATE_BINARY_SEARCH; + search->offset = search->ceiling_size - search->stride; + if (search->handler) { + ret = search->handler(search, offsetp); + if (!ret && + (*offsetp < + (search->total_size - search->min_size)) && + (*offsetp >= 0)) + return 0; + } + /* no break */ + case SEARCH_STATE_BINARY_SEARCH: + /* + * For efficient operation, we start with the largest stride + * possible and then decrease the stride on each iteration. We + * will check for a remainder when modding the offset with the + * previous stride. This makes it so that each offset is only + * checked once. + * + * At some point, programmer transaction overhead becomes + * greater than simply copying everything into RAM and + * checking one byte at a time. At some arbitrary point, we'll + * stop being clever and use brute force instead by copying + * the while ROM into RAM and searching one byte at a time. + * + * In practice, the flash map is usually stored in a + * write-protected section of flash which is often at the top + * of ROM where the boot vector on x86 resides. Because of + * this, we will search from top to bottom. + * + * We assume we can always return at least one offset here. + */ + *offsetp = search->offset; + + /* + * OK, now what offset should we return next? This loop skips + * any offsets that were already checked by larger strides. + */ + do { + search->offset -= search->stride; + } while (search->offset % (search->stride * 2) == 0); + + /* Move to next stride if necessary */ + if (search->offset < 0) { + search->stride /= 2; + search->offset = search->ceiling_size - search->stride; + while (search->offset > + (search->total_size - search->min_size)) + search->offset -= search->stride; + if (search->stride < 16) { + search->state = SEARCH_STATE_FULL_SEARCH; + search->offset = search->total_size - 1; + search->image = malloc(search->total_size); + if (!search->image) { + msg_gdbg("%s: failed to allocate %zd " + "bytes for search->image", + __func__, search->total_size); + return -1; + } + if (search->read_chunk(search->source_handle, + search->image, + 0, search->total_size)) { + msg_gdbg("[L%d] failed to read flash contents\n", + __LINE__); + return -1; + } + msg_gdbg("using brute force method to find fmap\n"); + } + } + return 0; + case SEARCH_STATE_FULL_SEARCH: + /* + * brute force + * We have read the entire ROM above, so the caller will be + * able to use search->image to access it. + * + * FIXME: This results in the entire ROM being read twice -- + * once here and again in doit(). The performance penalty + * needs to be dealt with before going upstream. + */ + do { + *offsetp = search->offset--; + } while (*offsetp > search->total_size - search->min_size); + if (search->offset < 0) + search->state = SEARCH_STATE_DONE; + return 0; + case SEARCH_STATE_DONE: + break; + } + + /* Give up, it is not there */ + return -1; +} + +void search_init(struct search_info *search, + void *source_handle, + size_t image_size, + size_t min_size, + int (*read_chunk)(void *handle, + void *dest, + size_t offset, + size_t size)) +{ + memset(search, '\0', sizeof(*search)); + search->min_size = min_size; + search->total_size = image_size; + search->source_handle = source_handle; + search->read_chunk = read_chunk; +} + +void search_free(struct search_info *search) +{ + if (search->image) + free(search->image); +} diff --git a/search.h b/search.h new file mode 100644 index 0000000..a1a5ac8 --- /dev/null +++ b/search.h @@ -0,0 +1,106 @@ +/* + * Copyright 2013, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * This is ported from the flashmap utility: http://flashmap.googlecode.com + */ + +#ifndef FLASHMAP_LIB_SEARCH_H__ +#define FLASHMAP_LIB_SEARCH_H__ + +/* Our current state in the search process */ +enum search_state_t { + SEARCH_STATE_START, + SEARCH_STATE_USE_HANDLER, /* Call handler function */ + SEARCH_STATE_BINARY_SEARCH, /* Fast binary search */ + SEARCH_STATE_FULL_SEARCH, /* Slow incremental search */ + SEARCH_STATE_DONE, /* Search completed */ +}; + +/* Keeps track of the state of our search */ +struct search_info { + void *source_handle; /* Pointer for read_chunk() below. */ + int (*read_chunk)(void *handle, /* Callback to read chunk of data. */ + void *dest, size_t offset, size_t size); + size_t total_size; /* Total size of the flash chip. */ + enum search_state_t state; /* Current state */ + size_t ceiling_size; /* Lowest power of 2 >= flash size */ + size_t stride; /* Current binary search stride */ + off_t offset; /* Next offset to return */ + uint8_t *image; /* Cache of entire flash image */ + size_t min_size; /* Minimum size of data to find */ + /* + * Utility wrapper for using external programs to aid in our search. + * @search: Pointer to search information + * @offset: Wrapper will set this if successful + * + * @return 0 if successful, -1 to indicate failure or offset not + * found by utility + */ + int (*handler)(struct search_info *search, off_t *offset); +}; + +/** + * search_find_next() - Find the next offset to check in a search operation + * + * If search->image is not NULL, then it contains the full flash image and + * the caller can use this instead of reading the data again. + * + * @search: Search information, set up by search_init() + * @offsetp: Returns next offset to check + * @return 0 if we have an offset, -1 if we have run out of places to look + */ +int search_find_next(struct search_info *search, off_t *offsetp); + +/** search_init() - Get ready to start a search + * + * @search: Search information, set up by this function + * @flash: Information about the flash chip + * @min_size: Minimum size of region that we want to find + */ +void search_init(struct search_info *search, + void *source_handle, + size_t image_size, + size_t min_size, + int (*read_chunk)(void *handle, + void *dest, + size_t offset, + size_t size)); + +/** search_free() - Free memory allocated by search + * + * @search: Search information, set up by search_init() + */ +void search_free(struct search_info *search); + +#endif -- To view, visit https://review.coreboot.org/c/flashrom/+/47061 To unsubscribe, or for help writing mail filters, visit https://review.coreboot.org/settings Gerrit-Project: flashrom Gerrit-Branch: master Gerrit-Change-Id: I7e4e90195b7857a4089d79264d471ede9ab79cd1 Gerrit-Change-Number: 47061 Gerrit-PatchSet: 1 Gerrit-Owner: Edward O'Callaghan <quasisec(a)chromium.org> Gerrit-MessageType: newchange

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