[PATCH v2 1/3] hw/sd: sd: Fix incorrect populated function switch status data structure

[Bin Meng]

At present the function switch status data structure bit [399:376]
are wrongly pupulated. These 3 bytes encode function switch status
for the 6 function groups, with 4 bits per group, starting from
function group 6 at bit 399, then followed by function group 5 at
bit 395, and so on.

However the codes mistakenly fills in the function group 1 status
at bit 399. This fixes the code logic.

Fixes: a1bb27b1e9 ("SD card emulation (initial implementation)")
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

---

Changes in v2:
- remove the pointless zero initialization

 hw/sd/sd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index fad9cf1..3226404 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -806,11 +806,12 @@ static void sd_function_switch(SDState *sd, uint32_t arg)
     sd->data[11] = 0x43;
     sd->data[12] = 0x80;       /* Supported group 1 functions */
     sd->data[13] = 0x03;
+
     for (i = 0; i < 6; i ++) {
         new_func = (arg >> (i * 4)) & 0x0f;
         if (mode && new_func != 0x0f)
             sd->function_group[i] = new_func;
-        sd->data[14 + (i >> 1)] = new_func << ((i * 4) & 4);
+        sd->data[16 - (i >> 1)] |= new_func << ((i % 2) * 4);
     }
     memset(&sd->data[17], 0, 47);
     stw_be_p(sd->data + 64, sd_crc16(sd->data, 64));
-- 
2.7.4