On 13.07.2010 17:02, Michael Karcher wrote:
Am Sonntag, den 11.07.2010, 01:02 +0200 schrieb Carl-Daniel Hailfinger:
-int it8716f_spi_chip_write_256(struct flashchip *flash, uint8_t *buf) +static int round_up(int val, int granularity) {
- int total_size = 1024 * flash->total_size;
- int i;
int tmp;
/* Premature optimization? You decide. */
if (!(granularity & (granularity - 1))) {
/* Granularity is a power of two. */return (val + granularity - 1) & ~ (granularity - 1);}
tmp = val % granularity;
if (!tmp)
return val;else
return val - tmp + granularity;+}
I in fact *do* decide. But not about the premature optimization, but about a premature generalization. Don't write a general round_up function, but just write the power-of-two case.
Since we're only handling a very special case (round_up_to_next_multiple_of_power_of_two_granularity) and use it only one time anyway, it doesn't really make sense to provide a separate function for this. Killed as per IRC discussion.
If you use the bitwise round-up here: Acked-by: Michael Karcher flashrom@mkarcher.dialup.fu-berlin.de
Thanks!
New patch follows.
Convert SPI chips to partial write, but wrap the write functions in a compat layer to allow converting the rest of flashrom later. I actually have patches for most of the remaining conversion, but I wanted to get this out and reviewed first.
Compile tested, and runtime tested on Intel NM10. I would really appreciate it if someone could test this on a machine with IT87 SPI flash.
Signed-off-by: Carl-Daniel Hailfinger c-d.hailfinger.devel.2006@gmx.net Acked-by: Michael Karcher flashrom@mkarcher.dialup.fu-berlin.de
Index: flashrom-partial_write_spi_intermediate/flash.h =================================================================== --- flashrom-partial_write_spi_intermediate/flash.h (Revision 1079) +++ flashrom-partial_write_spi_intermediate/flash.h (Arbeitskopie) @@ -456,6 +456,7 @@ int dummy_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr); int dummy_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len); +int dummy_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len); #endif
/* nic3com.c */ @@ -529,7 +530,7 @@ int ft2232_spi_init(void); int ft2232_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr); int ft2232_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len); -int ft2232_spi_write_256(struct flashchip *flash, uint8_t *buf); +int ft2232_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len);
/* bitbang_spi.c */ extern int bitbang_spi_half_period; @@ -537,7 +538,7 @@ int bitbang_spi_init(void); int bitbang_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr); int bitbang_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len); -int bitbang_spi_write_256(struct flashchip *flash, uint8_t *buf); +int bitbang_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len);
/* buspirate_spi.c */ struct buspirate_spispeeds { @@ -548,7 +549,7 @@ int buspirate_spi_shutdown(void); int buspirate_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr); int buspirate_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len); -int buspirate_spi_write_256(struct flashchip *flash, uint8_t *buf); +int buspirate_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len);
/* dediprog.c */ int dediprog_init(void); @@ -668,7 +669,7 @@
/* Optimized functions for this programmer */ int (*read)(struct flashchip *flash, uint8_t *buf, int start, int len); - int (*write_256)(struct flashchip *flash, uint8_t *buf); + int (*write_256)(struct flashchip *flash, uint8_t *buf, int start, int len); };
extern enum spi_controller spi_controller; @@ -689,7 +690,7 @@ int ich_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr); int ich_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len); -int ich_spi_write_256(struct flashchip *flash, uint8_t * buf); +int ich_spi_write_256(struct flashchip *flash, uint8_t * buf, int start, int len); int ich_spi_send_multicommand(struct spi_command *cmds);
/* it87spi.c */ @@ -701,13 +702,13 @@ int it8716f_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr); int it8716f_spi_chip_read(struct flashchip *flash, uint8_t *buf, int start, int len); -int it8716f_spi_chip_write_256(struct flashchip *flash, uint8_t *buf); +int it8716f_spi_chip_write_256(struct flashchip *flash, uint8_t *buf, int start, int len);
/* sb600spi.c */ int sb600_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr); int sb600_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len); -int sb600_spi_write_1(struct flashchip *flash, uint8_t *buf); +int sb600_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len); extern uint8_t *sb600_spibar;
/* wbsio_spi.c */ @@ -715,7 +716,7 @@ int wbsio_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr); int wbsio_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len); -int wbsio_spi_write_1(struct flashchip *flash, uint8_t *buf); +int wbsio_spi_write_1(struct flashchip *flash, uint8_t *buf, int start, int len);
/* serprog.c */ int serprog_init(void); Index: flashrom-partial_write_spi_intermediate/spi25.c =================================================================== --- flashrom-partial_write_spi_intermediate/spi25.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/spi25.c (Arbeitskopie) @@ -874,6 +874,7 @@
/* * Read a part of the flash chip. + * FIXME: Use the chunk code from Michael Karcher instead. * Each page is read separately in chunks with a maximum size of chunksize. */ int spi_read_chunked(struct flashchip *flash, uint8_t *buf, int start, int len, int chunksize) @@ -913,6 +914,7 @@
/* * Write a part of the flash chip. + * FIXME: Use the chunk code from Michael Karcher instead. * Each page is written separately in chunks with a maximum size of chunksize. */ int spi_write_chunked(struct flashchip *flash, uint8_t *buf, int start, int len, int chunksize) @@ -963,20 +965,13 @@ * and for chips where memory mapped programming is impossible * (e.g. due to size constraints in IT87* for over 512 kB) */ -int spi_chip_write_1(struct flashchip *flash, uint8_t *buf) +/* real chunksize is 1, logical chunksize is 1 */ +int spi_chip_write_1_new(struct flashchip *flash, uint8_t *buf, int start, int len) { - int total_size = 1024 * flash->total_size; int i, result = 0;
spi_disable_blockprotect(); - /* Erase first */ - msg_cinfo("Erasing flash before programming... "); - if (erase_flash(flash)) { - msg_cerr("ERASE FAILED!\n"); - return -1; - } - msg_cinfo("done.\n"); - for (i = 0; i < total_size; i++) { + for (i = start; i < start + len; i++) { result = spi_byte_program(i, buf[i]); if (result) return 1; @@ -987,11 +982,23 @@ return 0; }
-int spi_aai_write(struct flashchip *flash, uint8_t *buf) +int spi_chip_write_1(struct flashchip *flash, uint8_t *buf) { - uint32_t addr = 0; - uint32_t len = flash->total_size * 1024; - uint32_t pos = addr; + spi_disable_blockprotect(); + /* Erase first */ + msg_cinfo("Erasing flash before programming... "); + if (erase_flash(flash)) { + msg_cerr("ERASE FAILED!\n"); + return -1; + } + msg_cinfo("done.\n"); + + return spi_chip_write_1_new(flash, buf, 0, flash->total_size * 1024); +} + +int spi_aai_write(struct flashchip *flash, uint8_t *buf, int start, int len) +{ + uint32_t pos = start; int result; unsigned char cmd[JEDEC_AAI_WORD_PROGRAM_CONT_OUTSIZE] = { JEDEC_AAI_WORD_PROGRAM, @@ -1006,9 +1013,9 @@ .writecnt = JEDEC_AAI_WORD_PROGRAM_OUTSIZE, .writearr = (const unsigned char[]){ JEDEC_AAI_WORD_PROGRAM, - (pos >> 16) & 0xff, - (pos >> 8) & 0xff, - (pos & 0xff), + (start >> 16) & 0xff, + (start >> 8) & 0xff, + (start & 0xff), buf[0], buf[1] }, @@ -1026,17 +1033,21 @@ #if defined(__i386__) || defined(__x86_64__) case SPI_CONTROLLER_IT87XX: case SPI_CONTROLLER_WBSIO: - msg_cerr("%s: impossible with this SPI controller," + msg_perr("%s: impossible with this SPI controller," " degrading to byte program\n", __func__); - return spi_chip_write_1(flash, buf); + return spi_chip_write_1_new(flash, buf, start, len); #endif #endif default: break; }
+ /* The even start address and even length requirements can be either + * honored outside this function, or we can call spi_byte_program + * for the first and/or last byte and use AAI for the rest. + */ /* The data sheet requires a start address with the low bit cleared. */ - if (addr % 2) { + if (start % 2) { msg_cerr("%s: start address not even! Please report a bug at " "flashrom@flashrom.org\n", __func__); return SPI_GENERIC_ERROR; @@ -1048,15 +1059,14 @@ return SPI_GENERIC_ERROR; }
- if (erase_flash(flash)) { - msg_cerr("ERASE FAILED!\n"); - return -1; - }
result = spi_send_multicommand(cmds); if (result) { msg_cerr("%s failed during start command execution\n", __func__); + /* FIXME: Should we send WRDI here as well to make sure the chip + * is not in AAI mode? + */ return result; } while (spi_read_status_register() & JEDEC_RDSR_BIT_WIP) @@ -1065,7 +1075,7 @@ /* We already wrote 2 bytes in the multicommand step. */ pos += 2;
- while (pos < addr + len) { + while (pos < start + len) { cmd[1] = buf[pos++]; cmd[2] = buf[pos++]; spi_send_command(JEDEC_AAI_WORD_PROGRAM_CONT_OUTSIZE, 0, cmd, NULL); Index: flashrom-partial_write_spi_intermediate/it87spi.c =================================================================== --- flashrom-partial_write_spi_intermediate/it87spi.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/it87spi.c (Arbeitskopie) @@ -292,7 +292,7 @@ }
/* Page size is usually 256 bytes */ -static int it8716f_spi_page_program(struct flashchip *flash, int block, uint8_t *buf) +static int it8716f_spi_page_program(struct flashchip *flash, uint8_t *buf, int start) { int i; int result; @@ -305,7 +305,7 @@ OUTB(0x06, it8716f_flashport + 1); OUTB(((2 + (fast_spi ? 1 : 0)) << 4), it8716f_flashport); for (i = 0; i < 256; i++) { - chip_writeb(buf[256 * block + i], bios + 256 * block + i); + chip_writeb(buf[i], bios + start + i); } OUTB(0, it8716f_flashport); /* Wait until the Write-In-Progress bit is cleared. @@ -334,29 +334,39 @@ return 0; }
-int it8716f_spi_chip_write_256(struct flashchip *flash, uint8_t *buf) +int it8716f_spi_chip_write_256(struct flashchip *flash, uint8_t *buf, int start, int len) { - int total_size = 1024 * flash->total_size; - int i; - /* * IT8716F only allows maximum of 512 kb SPI chip size for memory * mapped access. */ - if ((programmer == PROGRAMMER_IT87SPI) || (total_size > 512 * 1024)) { - spi_chip_write_1(flash, buf); + if ((programmer == PROGRAMMER_IT87SPI) || (flash->total_size * 1024 > 512 * 1024)) { + spi_chip_write_1_new(flash, buf, start, len); } else { + int lenhere; spi_disable_blockprotect(); - /* Erase first */ - msg_pinfo("Erasing flash before programming... "); - if (erase_flash(flash)) { - msg_perr("ERASE FAILED!\n"); - return -1; + + if (start % 256) { + /* start to the end of the page or start + len, + * whichever is smaller. Page length is hardcoded to + * 256 bytes (IT87 SPI hardware limitation). + */ + lenhere = min(len, 256 - (start % 256)); + spi_chip_write_1_new(flash, buf, start, lenhere); + start += lenhere; + len -= lenhere; + buf += lenhere; } - msg_pinfo("done.\n"); - for (i = 0; i < total_size / 256; i++) { - it8716f_spi_page_program(flash, i, buf); + + /* FIXME: Handle chips which have max writechunk size >1 and <256. */ + while (len >= 256) { + it8716f_spi_page_program(flash, buf, start); + start += 256; + len -= 256; + buf += 256; } + if (len) + spi_chip_write_1_new(flash, buf, start, len); }
return 0; Index: flashrom-partial_write_spi_intermediate/buspirate_spi.c =================================================================== --- flashrom-partial_write_spi_intermediate/buspirate_spi.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/buspirate_spi.c (Arbeitskopie) @@ -309,18 +309,8 @@ return spi_read_chunked(flash, buf, start, len, 12); }
-int buspirate_spi_write_256(struct flashchip *flash, uint8_t *buf) +int buspirate_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len) { - int total_size = 1024 * flash->total_size; - spi_disable_blockprotect(); - /* Erase first. */ - msg_pinfo("Erasing flash before programming... "); - if (erase_flash(flash)) { - msg_perr("ERASE FAILED!\n"); - return -1; - } - msg_pinfo("done.\n"); - - return spi_write_chunked(flash, buf, 0, total_size, 12); + return spi_write_chunked(flash, buf, start, len, 12); } Index: flashrom-partial_write_spi_intermediate/bitbang_spi.c =================================================================== --- flashrom-partial_write_spi_intermediate/bitbang_spi.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/bitbang_spi.c (Arbeitskopie) @@ -139,10 +139,8 @@ return spi_read_chunked(flash, buf, start, len, 64 * 1024); }
-int bitbang_spi_write_256(struct flashchip *flash, uint8_t *buf) +int bitbang_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len) { - int total_size = 1024 * flash->total_size; - - msg_pdbg("total_size is %d\n", total_size); - return spi_write_chunked(flash, buf, 0, total_size, 256); + spi_disable_blockprotect(); + return spi_write_chunked(flash, buf, start, len, 256); } Index: flashrom-partial_write_spi_intermediate/flashchips.c =================================================================== --- flashrom-partial_write_spi_intermediate/flashchips.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/flashchips.c (Arbeitskopie) @@ -1423,7 +1423,7 @@ .block_erase = spi_block_erase_c7, } }, - .write = spi_aai_write, + .write = spi_chip_write_1, .read = spi_chip_read, },
Index: flashrom-partial_write_spi_intermediate/spi.c =================================================================== --- flashrom-partial_write_spi_intermediate/spi.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/spi.c (Arbeitskopie) @@ -66,7 +66,7 @@ .command = sb600_spi_send_command, .multicommand = default_spi_send_multicommand, .read = sb600_spi_read, - .write_256 = sb600_spi_write_1, + .write_256 = sb600_spi_write_256, },
{ /* SPI_CONTROLLER_VIA */ @@ -99,7 +99,7 @@ .command = dummy_spi_send_command, .multicommand = default_spi_send_multicommand, .read = dummy_spi_read, - .write_256 = NULL, + .write_256 = dummy_spi_write_256, }, #endif
@@ -117,7 +117,7 @@ .command = dediprog_spi_send_command, .multicommand = default_spi_send_multicommand, .read = dediprog_spi_read, - .write_256 = spi_chip_write_1, + .write_256 = spi_chip_write_1_new, }, #endif
@@ -196,8 +196,11 @@ /* * Program chip using page (256 bytes) programming. * Some SPI masters can't do this, they use single byte programming instead. + * The redirect to single byte programming is achieved by setting + * .write_256 = spi_chip_write_1 */ -int spi_chip_write_256(struct flashchip *flash, uint8_t *buf) +/* real chunksize is up to 256, logical chunksize is 256 */ +int spi_chip_write_256_new(struct flashchip *flash, uint8_t *buf, int start, int len) { if (!spi_programmer[spi_controller].write_256) { msg_perr("%s called, but SPI page write is unsupported on this " @@ -206,9 +209,30 @@ return 1; }
- return spi_programmer[spi_controller].write_256(flash, buf); + return spi_programmer[spi_controller].write_256(flash, buf, start, len); }
+/* Wrapper function until the generic code is converted to partial writes. */ +int spi_chip_write_256(struct flashchip *flash, uint8_t *buf) +{ + int ret; + + spi_disable_blockprotect(); + msg_pinfo("Erasing flash before programming... "); + if (erase_flash(flash)) { + msg_perr("ERASE FAILED!\n"); + return -1; + } + msg_pinfo("done.\n"); + msg_pinfo("Programming flash... "); + ret = spi_chip_write_256_new(flash, buf, 0, flash->total_size * 1024); + if (!ret) + msg_pinfo("done.\n"); + else + msg_pinfo("\n"); + return ret; +} + /* * Get the lowest allowed address for read accesses. This often happens to * be the lowest allowed address for all commands which take an address. Index: flashrom-partial_write_spi_intermediate/ft2232_spi.c =================================================================== --- flashrom-partial_write_spi_intermediate/ft2232_spi.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/ft2232_spi.c (Arbeitskopie) @@ -288,20 +288,10 @@ return spi_read_chunked(flash, buf, start, len, 64 * 1024); }
-int ft2232_spi_write_256(struct flashchip *flash, uint8_t *buf) +int ft2232_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len) { - int total_size = 1024 * flash->total_size; - spi_disable_blockprotect(); - /* Erase first. */ - msg_pinfo("Erasing flash before programming... "); - if (erase_flash(flash)) { - msg_perr("ERASE FAILED!\n"); - return -1; - } - msg_pinfo("done.\n"); - msg_pdbg("total_size is %d\n", total_size); - return spi_write_chunked(flash, buf, 0, total_size, 256); + return spi_write_chunked(flash, buf, start, len, 256); }
#endif Index: flashrom-partial_write_spi_intermediate/wbsio_spi.c =================================================================== --- flashrom-partial_write_spi_intermediate/wbsio_spi.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/wbsio_spi.c (Arbeitskopie) @@ -189,16 +189,14 @@ return read_memmapped(flash, buf, start, len); }
-int wbsio_spi_write_1(struct flashchip *flash, uint8_t *buf) +int wbsio_spi_write_1(struct flashchip *flash, uint8_t *buf, int start, int len) { - int size = flash->total_size * 1024; - - if (size > 1024 * 1024) { + if (flash->total_size * 1024 > 1024 * 1024) { msg_perr("%s: Winbond saved on 4 register bits so max chip size is 1024 KB!\n", __func__); return 1; }
- return spi_chip_write_1(flash, buf); + return spi_chip_write_1_new(flash, buf, start, len); }
#endif Index: flashrom-partial_write_spi_intermediate/dummyflasher.c =================================================================== --- flashrom-partial_write_spi_intermediate/dummyflasher.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/dummyflasher.c (Arbeitskopie) @@ -167,3 +167,12 @@ return spi_read_chunked(flash, buf, start, len, 64 * 1024); }
+/* Is is impossible to trigger this code path because dummyflasher probing will + * never be successful, and the current frontend refuses to write in that case. + * Other frontends may allow writing even for non-detected chips, though. + */ +int dummy_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len) +{ + spi_disable_blockprotect(); + return spi_write_chunked(flash, buf, start, len, 256); +} Index: flashrom-partial_write_spi_intermediate/sb600spi.c =================================================================== --- flashrom-partial_write_spi_intermediate/sb600spi.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/sb600spi.c (Arbeitskopie) @@ -48,25 +48,10 @@ return spi_read_chunked(flash, buf, start, len, 8); }
-/* FIXME: SB600 can write 5 bytes per transaction. */ -int sb600_spi_write_1(struct flashchip *flash, uint8_t *buf) +int sb600_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len) { - int total_size = flash->total_size * 1024; - int result = 0; - spi_disable_blockprotect(); - /* Erase first */ - msg_pinfo("Erasing flash before programming... "); - if (erase_flash(flash)) { - msg_perr("ERASE FAILED!\n"); - return -1; - } - msg_pinfo("done.\n"); - - msg_pinfo("Programming flash"); - result = spi_write_chunked(flash, buf, 0, total_size, 5); - msg_pinfo(" done.\n"); - return result; + return spi_write_chunked(flash, buf, start, len, 5); }
static void reset_internal_fifo_pointer(void) Index: flashrom-partial_write_spi_intermediate/ichspi.c =================================================================== --- flashrom-partial_write_spi_intermediate/ichspi.c (Revision 1079) +++ flashrom-partial_write_spi_intermediate/ichspi.c (Arbeitskopie) @@ -683,36 +683,15 @@ return spi_read_chunked(flash, buf, start, len, maxdata); }
-int ich_spi_write_256(struct flashchip *flash, uint8_t * buf) +int ich_spi_write_256(struct flashchip *flash, uint8_t * buf, int start, int len) { - int i, ret = 0; - int total_size = flash->total_size * 1024; - int erase_size = 64 * 1024; int maxdata = 64;
if (spi_controller == SPI_CONTROLLER_VIA) maxdata = 16;
spi_disable_blockprotect(); - /* Erase first */ - msg_pinfo("Erasing flash before programming... "); - if (erase_flash(flash)) { - msg_perr("ERASE FAILED!\n"); - return -1; - } - msg_pinfo("done.\n"); - - msg_pinfo("Programming page: \n"); - for (i = 0; i < total_size / erase_size; i++) { - ret = spi_write_chunked(flash, buf + (i * erase_size), - i * erase_size, erase_size, maxdata); - if (ret) - break; - } - - msg_pinfo("\n"); - - return ret; + return spi_write_chunked(flash, buf, start, len, maxdata); }
int ich_spi_send_command(unsigned int writecnt, unsigned int readcnt, Index: flashrom-partial_write_spi_intermediate/chipdrivers.h =================================================================== --- flashrom-partial_write_spi_intermediate/chipdrivers.h (Revision 1079) +++ flashrom-partial_write_spi_intermediate/chipdrivers.h (Arbeitskopie) @@ -43,6 +43,8 @@ int spi_block_erase_c7(struct flashchip *flash, unsigned int addr, unsigned int blocklen); int spi_chip_write_1(struct flashchip *flash, uint8_t *buf); int spi_chip_write_256(struct flashchip *flash, uint8_t *buf); +int spi_chip_write_1_new(struct flashchip *flash, uint8_t *buf, int start, int len); +int spi_chip_write_256_new(struct flashchip *flash, uint8_t *buf, int start, int len); int spi_chip_read(struct flashchip *flash, uint8_t *buf, int start, int len); uint8_t spi_read_status_register(void); int spi_disable_blockprotect(void); @@ -51,7 +53,7 @@ int spi_nbyte_read(int addr, uint8_t *bytes, int len); int spi_read_chunked(struct flashchip *flash, uint8_t *buf, int start, int len, int chunksize); int spi_write_chunked(struct flashchip *flash, uint8_t *buf, int start, int len, int chunksize); -int spi_aai_write(struct flashchip *flash, uint8_t *buf); +int spi_aai_write(struct flashchip *flash, uint8_t *buf, int start, int len);
/* 82802ab.c */ uint8_t wait_82802ab(chipaddr bios);