I had an issue to boot an A2 pandaboard from a Kingston 512MB SD card, I got the following output from X-Loader:
** Can't read from device 0 **
another Kingston 2GB SD card worked fine

it turned out that the problem is some missing delay in the MMC configuration code of X-loader, i.e. git://git.omapzoom.org/repo/x-loader.git, omap4_dev branch (the problem also exists with MLO from the minimal fs)

below patch fixes the issue for me:

diff --git a/cpu/omap4/mmc.c b/cpu/omap4/mmc.c
index efd7860..280e75b 100644
--- a/cpu/omap4/mmc.c
+++ b/cpu/omap4/mmc.c
@@ -547,6 +547,7 @@ unsigned char configure_mmc(mmc_card_data
*mmc_card_cur,
        if (dsor == 3)
                dsor = 4;
                        
+       printf("delaying\n");
        ret_val = mmc_clock_config(mmc_cont_cur, CLK_MISC, dsor);
        if (ret_val != 1)
                return ret_val;

posted at: 21:57 | path: /projects/PandaBoard | permanent link