sdcard: solve backup bug when sd is re-inserted

This issue was existent for a long time. While using the BitBox02,
when the sdcard is plugged into the device and the user unplugs
and replugs it, backup operations (e.g., list backups, restore
from backup) failed and throwed error from the firmware side.

Sdcard backup operations first check if the sdcard is inserted
before calling sdcard interface funtions. This commit fixes
the re-insertion problem by reinitializing the sdcard whenever
it is checked if it is inserted.

The problem earlier most probably stems from sdcard being in an
unexpected state when it is re-inserted. The forced initialization
step fixes the broken states.

Signed-off-by: asi345 <[email protected]>

CHANGELOG.md

@@ -8,6 +8,7 @@ customers cannot upgrade their bootloader, its changes are recorded separately.
 
 ### [Unreleased]
 - Update manufacturer HID descriptor to bitbox.swiss
+- SD card: solve backup bug when sd card is re-inserted
 
 ### 9.21.0
 - Bitcoin: add support for sending to silent payment (BIP-352) addresses

src/rust/bitbox02-rust/src/hww/api/sdcard.rs

@@ -23,6 +23,7 @@ use crate::workflow::sdcard;
 pub async fn process(
     &pb::InsertRemoveSdCardRequest { action }: &pb::InsertRemoveSdCardRequest,
 ) -> Result<Response, Error> {
+    bitbox02::sd::sdcard_init();
     let inserted = bitbox02::sd::sdcard_inserted();
     match SdCardAction::try_from(action) {
         Ok(SdCardAction::InsertCard) => {}

src/rust/bitbox02-sys/build.rs

@@ -116,6 +116,7 @@ const ALLOWLIST_FNS: &[&str] = &[
     "screen_process",
     "screen_saver_disable",
     "screen_saver_enable",
+    "sd_card_init",
     "sd_card_inserted",
     "sd_erase_file_in_subdir",
     "sd_format",

src/rust/bitbox02/src/sd.rs

@@ -19,6 +19,14 @@ use alloc::vec::Vec;
 use crate::util::str_to_cstr_vec;
 use bitbox02_sys::SD_MAX_FILE_SIZE;
 
+#[cfg(not(feature = "testing"))]
+pub fn sdcard_init() -> () {
+    unsafe { bitbox02_sys::sd_card_init() }
+}
+
+#[cfg(feature = "testing")]
+pub fn sdcard_init() {}
+
 #[cfg(not(feature = "testing"))]
 pub fn sdcard_inserted() -> bool {
     unsafe { bitbox02_sys::sd_card_inserted() }

src/sd.c

@@ -27,6 +27,7 @@
 #include "screen.h"
 #include "sd.h"
 #include "util.h"
+#include <sd_mmc/sd_mmc_start.h>
 
 #include <ff.h>
 
@@ -92,6 +93,11 @@ static bool _get_absolute_path(
     return true;
 }
 
+void sd_card_init(void)
+{
+    sd_mmc_start();
+}
+
 /**
  * Checks if an SD card is inserted and, if so, mounts it.
  * Resumes the bus clock. If mounting fails, pauses the bus clock.

src/sd.h

@@ -28,6 +28,7 @@ typedef struct {
     char** files;
 } sd_list_t;
 
+void sd_card_init(void);
 // the caller must free list_out using sd_free_list(). list_out itself is not
 // freed, as it could be passed as a stack var.
 USE_RESULT bool sd_list(sd_list_t* list_out);