From 0eebfaa58898acd4d5c3e6c02ce6cf3510c32629 Mon Sep 17 00:00:00 2001
From: streaksu <assemblyislaw@gmail.com>
Date: Mon, 3 Jan 2022 18:58:37 +0100
Subject: [PATCH] disk: Make disk_read_sectors() return errors instead of bool

---
 stage23/drivers/disk.h    |  8 +++++++-
 stage23/drivers/disk.s2.c | 19 ++++++++++---------
 stage23/lib/part.s2.c     | 14 ++++++++++++--
 3 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/stage23/drivers/disk.h b/stage23/drivers/disk.h
index 386194af..419d185d 100644
--- a/stage23/drivers/disk.h
+++ b/stage23/drivers/disk.h
@@ -14,7 +14,13 @@ struct volume *disk_volume_from_efi_handle(EFI_HANDLE efi_handle);
 
 #endif
 
+enum {
+    DISK_SUCCESS,
+    DISK_NO_MEDIA,
+    DISK_FAILURE
+};
+
 void disk_create_index(void);
-bool disk_read_sectors(struct volume *volume, void *buf, uint64_t block, size_t count);
+int disk_read_sectors(struct volume *volume, void *buf, uint64_t block, size_t count);
 
 #endif
diff --git a/stage23/drivers/disk.s2.c b/stage23/drivers/disk.s2.c
index 12c37c22..07094c91 100644
--- a/stage23/drivers/disk.s2.c
+++ b/stage23/drivers/disk.s2.c
@@ -89,7 +89,7 @@ static size_t fastest_xfer_size(struct volume *volume) {
     return fastest_size;
 }
 
-bool disk_read_sectors(struct volume *volume, void *buf, uint64_t block, size_t count) {
+int disk_read_sectors(struct volume *volume, void *buf, uint64_t block, size_t count) {
     struct dap dap = {0};
 
     if (count * volume->sector_size > XFER_BUF_SIZE)
@@ -113,13 +113,13 @@ bool disk_read_sectors(struct volume *volume, void *buf, uint64_t block, size_t
     rm_int(0x13, &r, &r);
 
     if (r.eflags & EFLAGS_CF) {
-        return false;
+        return DISK_FAILURE;
     }
 
     if (buf != NULL)
         memcpy(buf, xfer_buf, count * volume->sector_size);
 
-    return true;
+    return DISK_SUCCESS;
 }
 
 void disk_create_index(void) {
@@ -163,7 +163,7 @@ void disk_create_index(void) {
         if (drive_params.info_flags & (1 << 2) && drive > 0x8f) {
             // The medium could not be present (e.g.: CD-ROMs)
             // Do a test run to see if we can actually read it
-            if (!disk_read_sectors(block, NULL, 0, 1)) {
+            if (disk_read_sectors(block, NULL, 0, 1) != DISK_SUCCESS) {
                 continue;
             }
             block->index = optical_indices++;
@@ -200,17 +200,18 @@ void disk_create_index(void) {
 
 #if uefi == 1
 
-bool disk_read_sectors(struct volume *volume, void *buf, uint64_t block, size_t count) {
+int disk_read_sectors(struct volume *volume, void *buf, uint64_t block, size_t count) {
     EFI_STATUS status;
 
     status = volume->block_io->ReadBlocks(volume->block_io,
                                volume->block_io->Media->MediaId,
                                block, count * volume->sector_size, buf);
-    if (status != 0) {
-        return false;
+    
+    switch (status) {
+        case EFI_SUCCESS: return DISK_SUCCESS;
+        case EFI_NO_MEDIA: return DISK_NO_MEDIA;
+        default: return DISK_FAILURE;
     }
-
-    return true;
 }
 
 static alignas(4096) uint8_t unique_sector_pool[8192];
diff --git a/stage23/lib/part.s2.c b/stage23/lib/part.s2.c
index 8e089ac0..ed3e51bb 100644
--- a/stage23/lib/part.s2.c
+++ b/stage23/lib/part.s2.c
@@ -34,15 +34,25 @@ static bool cache_block(struct volume *volume, uint64_t block) {
 
     uint64_t xfer_size = volume->fastest_xfer_size;
 
-    while (!disk_read_sectors(volume, volume->cache,
+    for (;;) {
+        int ret = disk_read_sectors(volume, volume->cache,
                            first_sect + block * volume->fastest_xfer_size,
-                           xfer_size)) {
+                           xfer_size);
+
+        switch (ret) {
+            case DISK_NO_MEDIA:
+                return false;
+            case DISK_SUCCESS:
+                goto disk_success;
+        }
+
         xfer_size--;
         if (xfer_size == 0) {
             return false;
         }
     }
 
+disk_success:
     volume->cache_status = CACHE_READY;
     volume->cached_block = block;