| Message ID | 809516223.92250.1471987969563.JavaMail.zimbra@raptorengineeringinc.com |
|---|---|
| State | New |
| Headers | show |
Hi Timothy, Check out Hatim's GSOC work for manipulating status register and write protect bits: https://patchwork.coreboot.org/patch/4471/ https://patchwork.coreboot.org/patch/4472/ https://patchwork.coreboot.org/patch/4469/ https://patchwork.coreboot.org/patch/4467/ https://patchwork.coreboot.org/patch/4468/ https://patchwork.coreboot.org/patch/4470/ There's also similar work done in Chromium.org fork of flashrom which might do what you need (--wp-enable command): https://chromium.googlesource.com/chromiumos/third_party/flashrom/ On Tue, Aug 23, 2016 at 2:32 PM, Timothy Pearson < tpearson@raptorengineering.com> wrote: > RFC PATCH > > TPM-enabled systems require an immutable (or at least very difficult to > modify) CRTM, which can be provided via a locked bootblock sector. > > Add initial support for locking the upper 4K sector on Winbond Flash > ROMs. Unlocking the sector after it has been locked requires hardware > access to the write protect pin, satisfying the above requirements for many > use cases. > > To use, pass the --lock flag to Flashrom. This flag can be used in > isolation, or as part of a normal read / write / verify cycle. > > Index: spi25_statusreg.c > =================================================================== > --- spi25_statusreg.c (revision 1955) > +++ spi25_statusreg.c (working copy) > @@ -123,6 +123,78 @@ > return readarr[0]; > } > > +static uint8_t spi_read_status_register_2(struct flashctx *flash) > +{ > + static const unsigned char cmd[JEDEC_RDSR_OUTSIZE] = { JEDEC_RDSR2 > }; > + /* FIXME: No workarounds for driver/hardware bugs in generic code. > */ > + unsigned char readarr[2]; /* JEDEC_RDSR2_INSIZE=1 but wbsio needs > 2 */ > + int ret; > + > + /* Read Status Register */ > + ret = spi_send_command(flash, sizeof(cmd), sizeof(readarr), cmd, > readarr); > + if (ret) > + msg_cerr("RDSR2 failed!\n"); > + > + return readarr[0]; > +} > + > +/* Winbond sector protection enable that tries to set the status register > bits given. */ > +int spi_enable_sectorprotect_winbond(struct flashctx *flash, const > uint8_t status_flags) > +{ > + uint8_t status, status2; > + int result; > + uint8_t lock_mask = 0x80; > + uint8_t lock2_mask = 0x1; > + > + status = spi_read_status_register(flash); > + status2 = spi_read_status_register_2(flash); > + if ((status & lock_mask) != 0) { > + msg_cdbg("\n\tNeed to disable the register lock first... > "); > + if ((status2 & lock2_mask) != 0) { > + msg_cerr("Hardware protection is active, enabling > write protection is impossible.\n"); > + return 1; > + } > + /* All bits except the register lock bit (often called > SPRL, SRWD, WPEN) are readonly. */ > + result = spi_write_status_register(flash, status & > ~lock_mask); > + if (result) { > + msg_cerr("spi_write_status_register failed.\n"); > + return result; > + } > + status = spi_read_status_register(flash); > + if ((status & lock_mask) != 0) { > + msg_cerr("Unsetting lock bit(s) failed.\n"); > + return 1; > + } > + msg_cdbg("done.\n"); > + } > + > + /* Set requested protect bits */ > + result = spi_write_status_register(flash, status | (status_flags > << 2) ); > + if (result) { > + msg_cerr("spi_write_status_register failed.\n"); > + return result; > + } > + status = spi_read_status_register(flash); > + if ((status & (status_flags << 2)) != (status_flags << 2)) { > + msg_cerr("Setting lock bit(s) failed.\n"); > + return 1; > + } > + > + /* Set lock bit */ > + result = spi_write_status_register(flash, status | lock_mask); > + if (result) { > + msg_cerr("spi_write_status_register failed.\n"); > + return result; > + } > + status = spi_read_status_register(flash); > + if ((status & lock_mask) == 0) { > + msg_cerr("Setting lock bit(s) failed.\n"); > + return 1; > + } > + > + return 0; > +} > + > /* A generic block protection disable. > * Tests if a protection is enabled with the block protection mask > (bp_mask) and returns success otherwise. > * Tests if the register bits are locked with the lock_mask (lock_mask). > Index: flashrom.c > =================================================================== > --- flashrom.c (revision 1955) > +++ flashrom.c (working copy) > @@ -1977,7 +1977,7 @@ > * Besides that, the function itself is a textbook example of abysmal > code flow. > */ > int doit(struct flashctx *flash, int force, const char *filename, int > read_it, > - int write_it, int erase_it, int verify_it) > + int write_it, int erase_it, int verify_it, int lock_it) > { > uint8_t *oldcontents; > uint8_t *newcontents; > @@ -2129,6 +2129,13 @@ > msg_cinfo("VERIFIED.\n"); > } > > + if (lock_it && flash->chip->lock) { > + msg_cinfo("Locking upper 4K (bootblock)... "); > + ret = flash->chip->lock(flash, 0x11); > + if (!ret) > + msg_cinfo("LOCKED.\n"); > + } > + > out: > free(oldcontents); > free(newcontents); > Index: cli_classic.c > =================================================================== > --- cli_classic.c (revision 1955) > +++ cli_classic.c (working copy) > @@ -49,6 +49,7 @@ > " -r | --read <file> read flash and save to > <file>\n" > " -w | --write <file> write <file> to > flash\n" > " -v | --verify <file> verify flash against > <file>\n" > + " -u | --lock lock upper Flash > region (typically the 4K bootblock)\n" > " -E | --erase erase flash memory\n" > " -V | --verbose more verbose output\n" > " -c | --chip <chipname> probe only for > specified flash chip\n" > @@ -101,18 +102,19 @@ > #if CONFIG_PRINT_WIKI == 1 > int list_supported_wiki = 0; > #endif > - int read_it = 0, write_it = 0, erase_it = 0, verify_it = 0; > + int read_it = 0, write_it = 0, erase_it = 0, verify_it = 0, > lock_it = 0; > int dont_verify_it = 0, list_supported = 0, operation_specified = > 0; > enum programmer prog = PROGRAMMER_INVALID; > int ret = 0; > > - static const char optstring[] = "r:Rw:v:nVEfc:l:i:p:Lzho:"; > + static const char optstring[] = "r:Rw:v:nuVEfc:l:i:p:Lzho:"; > static const struct option long_options[] = { > {"read", 1, NULL, 'r'}, > {"write", 1, NULL, 'w'}, > {"erase", 0, NULL, 'E'}, > {"verify", 1, NULL, 'v'}, > {"noverify", 0, NULL, 'n'}, > + {"lock", 0, NULL, 'u'}, > {"chip", 1, NULL, 'c'}, > {"verbose", 0, NULL, 'V'}, > {"force", 0, NULL, 'f'}, > @@ -187,6 +189,9 @@ > } > dont_verify_it = 1; > break; > + case 'u': > + lock_it = 1; > + break; > case 'c': > chip_to_probe = strdup(optarg); > break; > @@ -522,7 +527,7 @@ > goto out_shutdown; > } > > - if (!(read_it | write_it | verify_it | erase_it)) { > + if (!(read_it | write_it | verify_it | erase_it | lock_it)) { > msg_ginfo("No operations were specified.\n"); > goto out_shutdown; > } > @@ -542,7 +547,7 @@ > * Give the chip time to settle. > */ > programmer_delay(100000); > - ret |= doit(fill_flash, force, filename, read_it, write_it, > erase_it, verify_it); > + ret |= doit(fill_flash, force, filename, read_it, write_it, > erase_it, verify_it, lock_it); > > unmap_flash(fill_flash); > out_shutdown: > Index: flashchips.c > =================================================================== > --- flashchips.c (revision 1955) > +++ flashchips.c (working copy) > @@ -14581,6 +14581,7 @@ > }, > .printlock = spi_prettyprint_status_register_plain, > /* TODO: improve */ > .unlock = spi_disable_blockprotect, > + .lock = spi_enable_sectorprotect_winbond, > .write = spi_chip_write_256, > .read = spi_chip_read, > .voltage = {2700, 3600}, > Index: chipdrivers.h > =================================================================== > --- chipdrivers.h (revision 1955) > +++ chipdrivers.h (working copy) > @@ -73,6 +73,7 @@ > int spi_prettyprint_status_register_bp4_srwd(struct flashctx *flash); > int spi_prettyprint_status_register_bp2_bpl(struct flashctx *flash); > int spi_prettyprint_status_register_bp2_tb_bpl(struct flashctx *flash); > +int spi_enable_sectorprotect_winbond(struct flashctx *flash, const > uint8_t status_flags); > int spi_disable_blockprotect(struct flashctx *flash); > int spi_disable_blockprotect_bp1_srwd(struct flashctx *flash); > int spi_disable_blockprotect_bp2_srwd(struct flashctx *flash); > Index: flash.h > =================================================================== > --- flash.h (revision 1955) > +++ flash.h (working copy) > @@ -200,6 +200,7 @@ > } block_erasers[NUM_ERASEFUNCTIONS]; > > int (*printlock) (struct flashctx *flash); > + int (*lock) (struct flashctx *flash, const uint8_t status_flags); > int (*unlock) (struct flashctx *flash); > int (*write) (struct flashctx *flash, const uint8_t *buf, unsigned > int start, unsigned int len); > int (*read) (struct flashctx *flash, uint8_t *buf, unsigned int > start, unsigned int len); > @@ -281,7 +282,7 @@ > void print_banner(void); > void list_programmers_linebreak(int startcol, int cols, int paren); > int selfcheck(void); > -int doit(struct flashctx *flash, int force, const char *filename, int > read_it, int write_it, int erase_it, int verify_it); > +int doit(struct flashctx *flash, int force, const char *filename, int > read_it, int write_it, int erase_it, int verify_it, int lock_it); > int read_buf_from_file(unsigned char *buf, unsigned long size, const char > *filename); > int write_buf_to_file(const unsigned char *buf, unsigned long size, const > char *filename); > > Index: spi.h > =================================================================== > --- spi.h (revision 1955) > +++ spi.h (working copy) > @@ -121,6 +121,11 @@ > #define JEDEC_RDSR_OUTSIZE 0x01 > #define JEDEC_RDSR_INSIZE 0x01 > > +/* Read Status Register 2 */ > +#define JEDEC_RDSR2 0x35 > +#define JEDEC_RDSR2_OUTSIZE 0x01 > +#define JEDEC_RDSR2_INSIZE 0x01 > + > /* Status Register Bits */ > #define SPI_SR_WIP (0x01 << 0) > #define SPI_SR_WEL (0x01 << 1) > > _______________________________________________ > flashrom mailing list > flashrom@flashrom.org > https://www.flashrom.org/mailman/listinfo/flashrom >
Index: spi25_statusreg.c =================================================================== --- spi25_statusreg.c (revision 1955) +++ spi25_statusreg.c (working copy) @@ -123,6 +123,78 @@ return readarr[0]; } +static uint8_t spi_read_status_register_2(struct flashctx *flash) +{ + static const unsigned char cmd[JEDEC_RDSR_OUTSIZE] = { JEDEC_RDSR2 }; + /* FIXME: No workarounds for driver/hardware bugs in generic code. */ + unsigned char readarr[2]; /* JEDEC_RDSR2_INSIZE=1 but wbsio needs 2 */ + int ret; + + /* Read Status Register */ + ret = spi_send_command(flash, sizeof(cmd), sizeof(readarr), cmd, readarr); + if (ret) + msg_cerr("RDSR2 failed!\n"); + + return readarr[0]; +} + +/* Winbond sector protection enable that tries to set the status register bits given. */ +int spi_enable_sectorprotect_winbond(struct flashctx *flash, const uint8_t status_flags) +{ + uint8_t status, status2; + int result; + uint8_t lock_mask = 0x80; + uint8_t lock2_mask = 0x1; + + status = spi_read_status_register(flash); + status2 = spi_read_status_register_2(flash); + if ((status & lock_mask) != 0) { + msg_cdbg("\n\tNeed to disable the register lock first... "); + if ((status2 & lock2_mask) != 0) { + msg_cerr("Hardware protection is active, enabling write protection is impossible.\n"); + return 1; + } + /* All bits except the register lock bit (often called SPRL, SRWD, WPEN) are readonly. */ + result = spi_write_status_register(flash, status & ~lock_mask); + if (result) { + msg_cerr("spi_write_status_register failed.\n"); + return result; + } + status = spi_read_status_register(flash); + if ((status & lock_mask) != 0) { + msg_cerr("Unsetting lock bit(s) failed.\n"); + return 1; + } + msg_cdbg("done.\n"); + } + + /* Set requested protect bits */ + result = spi_write_status_register(flash, status | (status_flags << 2) ); + if (result) { + msg_cerr("spi_write_status_register failed.\n"); + return result; + } + status = spi_read_status_register(flash); + if ((status & (status_flags << 2)) != (status_flags << 2)) { + msg_cerr("Setting lock bit(s) failed.\n"); + return 1; + } + + /* Set lock bit */ + result = spi_write_status_register(flash, status | lock_mask); + if (result) { + msg_cerr("spi_write_status_register failed.\n"); + return result; + } + status = spi_read_status_register(flash); + if ((status & lock_mask) == 0) { + msg_cerr("Setting lock bit(s) failed.\n"); + return 1; + } + + return 0; +} + /* A generic block protection disable. * Tests if a protection is enabled with the block protection mask (bp_mask) and returns success otherwise. * Tests if the register bits are locked with the lock_mask (lock_mask). Index: flashrom.c =================================================================== --- flashrom.c (revision 1955) +++ flashrom.c (working copy) @@ -1977,7 +1977,7 @@ * Besides that, the function itself is a textbook example of abysmal code flow. */ int doit(struct flashctx *flash, int force, const char *filename, int read_it, - int write_it, int erase_it, int verify_it) + int write_it, int erase_it, int verify_it, int lock_it) { uint8_t *oldcontents; uint8_t *newcontents; @@ -2129,6 +2129,13 @@ msg_cinfo("VERIFIED.\n"); } + if (lock_it && flash->chip->lock) { + msg_cinfo("Locking upper 4K (bootblock)... "); + ret = flash->chip->lock(flash, 0x11); + if (!ret) + msg_cinfo("LOCKED.\n"); + } + out: free(oldcontents); free(newcontents); Index: cli_classic.c =================================================================== --- cli_classic.c (revision 1955) +++ cli_classic.c (working copy) @@ -49,6 +49,7 @@ " -r | --read <file> read flash and save to <file>\n" " -w | --write <file> write <file> to flash\n" " -v | --verify <file> verify flash against <file>\n" + " -u | --lock lock upper Flash region (typically the 4K bootblock)\n" " -E | --erase erase flash memory\n" " -V | --verbose more verbose output\n" " -c | --chip <chipname> probe only for specified flash chip\n" @@ -101,18 +102,19 @@ #if CONFIG_PRINT_WIKI == 1 int list_supported_wiki = 0; #endif - int read_it = 0, write_it = 0, erase_it = 0, verify_it = 0; + int read_it = 0, write_it = 0, erase_it = 0, verify_it = 0, lock_it = 0; int dont_verify_it = 0, list_supported = 0, operation_specified = 0; enum programmer prog = PROGRAMMER_INVALID; int ret = 0; - static const char optstring[] = "r:Rw:v:nVEfc:l:i:p:Lzho:"; + static const char optstring[] = "r:Rw:v:nuVEfc:l:i:p:Lzho:"; static const struct option long_options[] = { {"read", 1, NULL, 'r'}, {"write", 1, NULL, 'w'}, {"erase", 0, NULL, 'E'}, {"verify", 1, NULL, 'v'}, {"noverify", 0, NULL, 'n'}, + {"lock", 0, NULL, 'u'}, {"chip", 1, NULL, 'c'}, {"verbose", 0, NULL, 'V'}, {"force", 0, NULL, 'f'}, @@ -187,6 +189,9 @@ } dont_verify_it = 1; break; + case 'u': + lock_it = 1; + break; case 'c': chip_to_probe = strdup(optarg); break; @@ -522,7 +527,7 @@ goto out_shutdown; } - if (!(read_it | write_it | verify_it | erase_it)) { + if (!(read_it | write_it | verify_it | erase_it | lock_it)) { msg_ginfo("No operations were specified.\n"); goto out_shutdown; } @@ -542,7 +547,7 @@ * Give the chip time to settle. */ programmer_delay(100000); - ret |= doit(fill_flash, force, filename, read_it, write_it, erase_it, verify_it); + ret |= doit(fill_flash, force, filename, read_it, write_it, erase_it, verify_it, lock_it); unmap_flash(fill_flash); out_shutdown: Index: flashchips.c =================================================================== --- flashchips.c (revision 1955) +++ flashchips.c (working copy) @@ -14581,6 +14581,7 @@ }, .printlock = spi_prettyprint_status_register_plain, /* TODO: improve */ .unlock = spi_disable_blockprotect, + .lock = spi_enable_sectorprotect_winbond, .write = spi_chip_write_256, .read = spi_chip_read, .voltage = {2700, 3600}, Index: chipdrivers.h =================================================================== --- chipdrivers.h (revision 1955) +++ chipdrivers.h (working copy) @@ -73,6 +73,7 @@ int spi_prettyprint_status_register_bp4_srwd(struct flashctx *flash); int spi_prettyprint_status_register_bp2_bpl(struct flashctx *flash); int spi_prettyprint_status_register_bp2_tb_bpl(struct flashctx *flash); +int spi_enable_sectorprotect_winbond(struct flashctx *flash, const uint8_t status_flags); int spi_disable_blockprotect(struct flashctx *flash); int spi_disable_blockprotect_bp1_srwd(struct flashctx *flash); int spi_disable_blockprotect_bp2_srwd(struct flashctx *flash); Index: flash.h =================================================================== --- flash.h (revision 1955) +++ flash.h (working copy) @@ -200,6 +200,7 @@ } block_erasers[NUM_ERASEFUNCTIONS]; int (*printlock) (struct flashctx *flash); + int (*lock) (struct flashctx *flash, const uint8_t status_flags); int (*unlock) (struct flashctx *flash); int (*write) (struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len); int (*read) (struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len); @@ -281,7 +282,7 @@ void print_banner(void); void list_programmers_linebreak(int startcol, int cols, int paren); int selfcheck(void); -int doit(struct flashctx *flash, int force, const char *filename, int read_it, int write_it, int erase_it, int verify_it); +int doit(struct flashctx *flash, int force, const char *filename, int read_it, int write_it, int erase_it, int verify_it, int lock_it); int read_buf_from_file(unsigned char *buf, unsigned long size, const char *filename); int write_buf_to_file(const unsigned char *buf, unsigned long size, const char *filename); Index: spi.h =================================================================== --- spi.h (revision 1955) +++ spi.h (working copy) @@ -121,6 +121,11 @@ #define JEDEC_RDSR_OUTSIZE 0x01 #define JEDEC_RDSR_INSIZE 0x01 +/* Read Status Register 2 */ +#define JEDEC_RDSR2 0x35 +#define JEDEC_RDSR2_OUTSIZE 0x01 +#define JEDEC_RDSR2_INSIZE 0x01 + /* Status Register Bits */ #define SPI_SR_WIP (0x01 << 0) #define SPI_SR_WEL (0x01 << 1)