From 73f5bda01dbb1f6726593ab7a6139a1a8a1afb5a Mon Sep 17 00:00:00 2001 From: Stefan Tauner Date: Sun, 19 Oct 2014 07:53:45 +0000 Subject: Make read before write configurable (infrastructure part) - Introduce a variable in doit() that allows to influence read-before-write and its consequences. - Modify build_new_image so that it still works even if the old content is not read before. - Add copy_old_content() to ease the pain for future patches. Corresponding to flashrom svn r1851. Signed-off-by: Stefan Tauner Signed-off-by: Carl-Daniel Hailfinger Acked-by: Stefan Tauner --- flash.h | 2 +- flashrom.c | 34 +++++++++++++++++++++++----------- layout.c | 31 ++++++++++++++++++++++++++----- 3 files changed, 50 insertions(+), 17 deletions(-) diff --git a/flash.h b/flash.h index 03b26e7..ff4b06b 100644 --- a/flash.h +++ b/flash.h @@ -341,7 +341,7 @@ int register_include_arg(char *name); int process_include_args(void); int read_romlayout(const char *name); int normalize_romentries(const struct flashctx *flash); -int build_new_image(const struct flashctx *flash, uint8_t *oldcontents, uint8_t *newcontents); +int build_new_image(struct flashctx *flash, bool oldcontents_valid, uint8_t *oldcontents, uint8_t *newcontents); void layout_cleanup(void); /* spi.c */ diff --git a/flashrom.c b/flashrom.c index 9b82d4c..27bc36a 100644 --- a/flashrom.c +++ b/flashrom.c @@ -1906,6 +1906,7 @@ int doit(struct flashctx *flash, int force, const char *filename, int read_it, uint8_t *newcontents; int ret = 0; unsigned long size = flash->chip->total_size * 1024; + int read_all_first = 1; /* FIXME: Make this configurable. */ if (chip_safety_check(flash, force, read_it, write_it, erase_it, verify_it)) { msg_cerr("Aborting.\n"); @@ -1983,26 +1984,33 @@ int doit(struct flashctx *flash, int force, const char *filename, int read_it, /* Read the whole chip to be able to check whether regions need to be * erased and to give better diagnostics in case write fails. - * The alternative would be to read only the regions which are to be + * The alternative is to read only the regions which are to be * preserved, but in that case we might perform unneeded erase which * takes time as well. */ - msg_cinfo("Reading old flash chip contents... "); - if (flash->chip->read(flash, oldcontents, 0, size)) { - ret = 1; - msg_cinfo("FAILED.\n"); - goto out; + if (read_all_first) { + msg_cinfo("Reading old flash chip contents... "); + if (flash->chip->read(flash, oldcontents, 0, size)) { + ret = 1; + msg_cinfo("FAILED.\n"); + goto out; + } } msg_cinfo("done.\n"); /* Build a new image taking the given layout into account. */ - build_new_image(flash, oldcontents, newcontents); + if (build_new_image(flash, read_all_first, oldcontents, newcontents)) { + msg_gerr("Could not prepare the data to be written, aborting.\n"); + ret = 1; + goto out; + } // //////////////////////////////////////////////////////////// - if (write_it) { - if (erase_and_write_flash(flash, oldcontents, newcontents)) { - msg_cerr("Uh oh. Erase/write failed. Checking if anything has changed.\n"); + if (write_it && erase_and_write_flash(flash, oldcontents, newcontents)) { + msg_cerr("Uh oh. Erase/write failed."); + if (read_all_first) { + msg_cerr("Checking if anything has changed.\n"); msg_cinfo("Reading current flash chip contents... "); if (!flash->chip->read(flash, newcontents, 0, size)) { msg_cinfo("done.\n"); @@ -2017,7 +2025,11 @@ int doit(struct flashctx *flash, int force, const char *filename, int read_it, emergency_help_message(); ret = 1; goto out; - } + } else + msg_cerr("\n"); + emergency_help_message(); + ret = 1; + goto out; } /* Verify only if we either did not try to write (verify operation) or actually changed something. */ diff --git a/layout.c b/layout.c index a12eb28..0b9f6e5 100644 --- a/layout.c +++ b/layout.c @@ -257,7 +257,28 @@ int normalize_romentries(const struct flashctx *flash) return ret; } -int build_new_image(const struct flashctx *flash, uint8_t *oldcontents, uint8_t *newcontents) +static int copy_old_content(struct flashctx *flash, int oldcontents_valid, uint8_t *oldcontents, uint8_t *newcontents, unsigned int start, unsigned int size) +{ + if (!oldcontents_valid) { + /* oldcontents is a zero-filled buffer. By reading the current data into oldcontents here, we + * avoid a rewrite of identical regions even if an initial full chip read didn't happen. */ + msg_gdbg2("Read a chunk starting at 0x%06x (len=0x%06x).\n", start, size); + int ret = flash->chip->read(flash, oldcontents + start, start, size); + if (ret != 0) { + msg_gerr("Failed to read chunk 0x%06x-0x%06x.\n", start, start + size - 1); + return 1; + } + } + memcpy(newcontents + start, oldcontents + start, size); + return 0; +} + +/** + * Modify @newcontents so that it contains the data that should be on the chip eventually. In the case the user + * wants to update only parts of it, copy the chunks to be preserved from @oldcontents to @newcontents. If + * @oldcontents is not valid, we need to fetch the current data from the chip first. + */ +int build_new_image(struct flashctx *flash, bool oldcontents_valid, uint8_t *oldcontents, uint8_t *newcontents) { unsigned int start = 0; romentry_t *entry; @@ -276,14 +297,14 @@ int build_new_image(const struct flashctx *flash, uint8_t *oldcontents, uint8_t entry = get_next_included_romentry(start); /* No more romentries for remaining region? */ if (!entry) { - memcpy(newcontents + start, oldcontents + start, - size - start); + copy_old_content(flash, oldcontents_valid, oldcontents, newcontents, start, + size - start); break; } /* For non-included region, copy from old content. */ if (entry->start > start) - memcpy(newcontents + start, oldcontents + start, - entry->start - start); + copy_old_content(flash, oldcontents_valid, oldcontents, newcontents, start, + entry->start - start); /* Skip to location after current romentry. */ start = entry->end + 1; /* Catch overflow. */ -- cgit v1.1