hw/sd/sdcard: Explicit dummy byte value

On error the DAT lines are left unmodified to their
previous states. QEMU returns 0x00 for convenience.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240730092138.32443-2-philmd@linaro.org>
This commit is contained in:
Philippe Mathieu-Daudé 2024-07-30 09:45:48 +02:00
parent 3fad6db79e
commit 22d5fb42a8

View file

@ -2478,20 +2478,22 @@ void sd_write_byte(SDState *sd, uint8_t value)
uint8_t sd_read_byte(SDState *sd) uint8_t sd_read_byte(SDState *sd)
{ {
/* TODO: Append CRCs */ /* TODO: Append CRCs */
const uint8_t dummy_byte = 0x00;
uint8_t ret; uint8_t ret;
uint32_t io_len; uint32_t io_len;
if (!sd->blk || !blk_is_inserted(sd->blk) || !sd->enable) if (!sd->blk || !blk_is_inserted(sd->blk) || !sd->enable)
return 0x00; return dummy_byte;
if (sd->state != sd_sendingdata_state) { if (sd->state != sd_sendingdata_state) {
qemu_log_mask(LOG_GUEST_ERROR, qemu_log_mask(LOG_GUEST_ERROR,
"%s: not in Sending-Data state\n", __func__); "%s: not in Sending-Data state\n", __func__);
return 0x00; return dummy_byte;
} }
if (sd->card_status & (ADDRESS_ERROR | WP_VIOLATION)) if (sd->card_status & (ADDRESS_ERROR | WP_VIOLATION)) {
return 0x00; return dummy_byte;
}
io_len = sd_blk_len(sd); io_len = sd_blk_len(sd);
@ -2517,7 +2519,7 @@ uint8_t sd_read_byte(SDState *sd)
if (sd->data_offset == 0) { if (sd->data_offset == 0) {
if (!address_in_range(sd, "READ_MULTIPLE_BLOCK", if (!address_in_range(sd, "READ_MULTIPLE_BLOCK",
sd->data_start, io_len)) { sd->data_start, io_len)) {
return 0x00; return dummy_byte;
} }
sd_blk_read(sd, sd->data_start, io_len); sd_blk_read(sd, sd->data_start, io_len);
} }