From 2d2512453b9a27e4da9a82c5eafb4ad3fcf55d20 Mon Sep 17 00:00:00 2001 From: Carl-Daniel Hailfinger Date: Fri, 24 Feb 2012 23:49:30 +0000 Subject: SFDP: Fetch parameter table in a more portable way SFDP parameter table reads expect a dummy byte between written data (opcode+address) and read data on the SPI bus. Read that dummy byte instead of writing it to be compatible with all programmer drivers. Reduce SFDP parameter table read chunk size from 8 to 2 to handle programmers with small readcount limits. Corresponding to flashrom svn r1506. Signed-off-by: Carl-Daniel Hailfinger Acked-by: Stefan Tauner --- sfdp.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/sfdp.c b/sfdp.c index 123c982d..39d59e03 100644 --- a/sfdp.c +++ b/sfdp.c @@ -19,6 +19,7 @@ #include #include +#include #include "flash.h" #include "spi.h" #include "chipdrivers.h" @@ -26,31 +27,39 @@ static int spi_sfdp_read_sfdp_chunk(struct flashctx *flash, uint32_t address, uint8_t *buf, int len) { int i, ret; + uint8_t *newbuf; const unsigned char cmd[JEDEC_SFDP_OUTSIZE] = { JEDEC_SFDP, (address >> 16) & 0xff, (address >> 8) & 0xff, (address >> 0) & 0xff, /* FIXME: the following dummy byte explodes on some programmers. - * One possible workaround would be to read the dummy byte + * One workaround is to read the dummy byte * instead and discard its value. */ 0 }; msg_cspew("%s: addr=0x%x, len=%d, data:\n", __func__, address, len); - ret = spi_send_command(flash, sizeof(cmd), len, cmd, buf); + newbuf = malloc(len + 1); + if (!newbuf) + return SPI_PROGRAMMER_ERROR; + ret = spi_send_command(flash, sizeof(cmd) - 1, len + 1, cmd, newbuf); + memmove(buf, newbuf + 1, len); + free(newbuf); + if (ret) + return ret; for (i = 0; i < len; i++) msg_cspew(" 0x%02x", buf[i]); msg_cspew("\n"); - return ret; + return 0; } static int spi_sfdp_read_sfdp(struct flashctx *flash, uint32_t address, uint8_t *buf, int len) { - /* FIXME: this is wrong. There are different upper bounds for the number - * of bytes to read on the various programmers (even depending on the - * rest of the structure of the transaction).*/ - int maxstep = 8; + /* FIXME: There are different upper bounds for the number of bytes to + * read on the various programmers (even depending on the rest of the + * structure of the transaction). 2 is a safe bet. */ + int maxstep = 2; int ret = 0; while (len > 0) { int step = min(len, maxstep); -- cgit v1.2.3