On 21.12.2010 08:21, Albert ARIBAUD wrote:
Hi Dirk,
Le 21/12/2010 08:11, Dirk Behme a écrit :
But the issue with drivers/mtd/nand/omap_gpmc.c (i.e. the additional ldrb r3, [r3]) is still open? Has anybody tried to replace it with a nop in the binary to be sure this is the root cause?
Can you try and preprocess the C file for both the broken and working cases, then post the preprocessed C extract? Differences at the C level may help understanding differences at the asm level.
gcc version 4.5.1 (Sourcery G++ Lite 2010.09-50)
Work: ====
static void omap_nand_hwcontrol(struct mtd_info *mtd, int32_t cmd, uint32_t ctrl) { register struct nand_chip *this = mtd->priv; ... if (cmd != -1)
(*(volatile unsigned char *)(this->IO_ADDR_W) = (cmd)); }
if (cmd != NAND_CMD_NONE) 84: e3710001 cmn r1, #1 origwriteb(cmd, this->IO_ADDR_W); 88: 15933004 ldrne r3, [r3, #4] 8c: 120110ff andne r1, r1, #255 ; 0xff 90: 15c31000 strbne r1, [r3] 94: e12fff1e bx lr ...
Broken: ======
static void omap_nand_hwcontrol(struct mtd_info *mtd, int32_t cmd, uint32_t ctrl) { register struct nand_chip *this = mtd->priv; ... if (cmd != -1) ({ do { } while (0); (*(volatile unsigned char *)(this->IO_ADDR_W) = (cmd)); }); }
if (cmd != NAND_CMD_NONE) 84: e3710001 cmn r1, #1 writeb(cmd, this->IO_ADDR_W); 88: 15933004 ldrne r3, [r3, #4] 8c: 120110ff andne r1, r1, #255 ; 0xff 90: 15c31000 strbne r1, [r3] 94: 15d33000 ldrbne r3, [r3] 98: e12fff1e bx lr ...
The issue seems to be the additional 'ldrbne r3, [r3]' added by the compiler in the broken version.
Best regards
Dirk