[U-Boot] gcc optimizing option cause printf() and others crash.why?

[yaojin liu]

I use arm-2009q1-203-arm-none-linux-gnueabi-i686-pc-linux-gnu.tar.gz to
compile uboot1.3.4, and found that if I set OPTFLAGS to -O1,or O2, uboot
will crash, usually in printf().
when i set to O3, it runs to prompt, but after several seconds(or minutes),
the code is dead,and the console has no response.
Os also has the problem,usually cannot run to main_loop().
How should i resolve this problem?

2010/7/29 yaojin liu <lanmanck at gmail.com>

> hi,all:
> I encounter strange thing again. :(
>
> it seems the vsprintf will overrun. have someone met before?
>
> To debug it ,I define a function writing character directly to the
> register: "u_sendstring()"
>
> Here is the code for debugging printf:
>
>  void printf(const char *fmt, ...)
>
> {
>
> va_list args;
>
> uint i;
>
> char printbuffer[CONFIG_SYS_PBSIZE];
>
> va_start(args, fmt);
>
> /* For this to work, printbuffer must be larger than
>
> * anything we ever want to print.
>
> */
>
> u_sendstring("printf2\n");
>
> i = vsprintf(printbuffer, fmt, args);
>
> u_sendstring("printf3\n");
>
> va_end(args);
>
> puts(printbuffer);
>
> }
>
> and here is the output:
>
> DM3xx=>>:    DONEprintf2
>
> DM3xx=>>: printf3
>
> DM3xx=>>: U-Boot 2009.03 ( 2010 - 23:14:17)
>
> DM3xx=>>: I2C:   ready
>
> DM3xx=>>: DRAM:  printf2
>
> DM3xx=>>: printf3
>
> DM3xx=>>: 128printf2
>
> DM3xx=>>: printf3
>
> DM3xx=>>:  MB
>
> DM3xx=>>: NAND:  board_nand_init end
>
> DM3xx=>>: nand_scan1
>
> DM3xx=>>: nand_scan_ident1
>
> DM3xx=>>: nand_scan_ident2
>
> DM3xx=>>: nand_get_flash_type1
>
> DM3xx=>>: nand_get_flash_type2
>
> DM3xx=>>: nand_get_flash_type4
>
> DM3xx=>>: printf2n BOOTME
>
> DM3xx=>>:  BOOTME
>
> DM3xx=>>:  BOOTME
>
> DM3xx=>>:  BOOTME
>
>
> /////////////////////// weill, you can see that the first string will
> output correctly,such as "128" "MB", but when it ran
> to nand_get_flash_type(), the chip reboot.
>
> static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
> struct nand_chip *chip, int busw, int *maf_id)
>
> {
>
> struct nand_flash_dev *type = NULL;
>
> int i, dev_id, maf_idx;
>
> int tmp_id, tmp_manf;
>
> /* Select the device */
>
> chip->select_chip(mtd, 0);
>
> u_sendstring("nand_get_flash_type1\n");
>
> .....
>
> u_sendstring("nand_get_flash_type4\n");
>
> printk("NAND device: Manufacturer ID:"
>
>          " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id, dev_id,
>
>          nand_manuf_ids[maf_idx].name, type->name);
>
> u_sendstring("nand_get_flash_type5\n");
>
> return type;
>
> }
>
> printk is just printf. So as i describe above, the code ran to vsprintf and
> no respond anymore.
> How could this happen? Is it another hardware bug?
>
>