stos: bpal: Add memory map callbacks

Signed-off-by: Chloe M. <chloe@mensia.org>

paw/stos/ke/bpal/proto/limine.c

@@ -43,6 +43,13 @@ static struct limine_bootloader_performance_request LoaderPerReq = {
     .revision = 0
 };
 
+/* Memory map request */
+static struct limine_memmap_response *MapResp = NULL;
+static volatile struct limine_memmap_request MapReq = {
+    .id = LIMINE_MEMMAP_REQUEST_ID,
+    .revision = 0
+};
+
 VOID
 BpalInitFramebuffer(BPAL_HANDLE *Handle)
 {
@@ -65,6 +72,22 @@ BpalInitFramebuffer(BPAL_HANDLE *Handle)
     Framebuffer->BlueMaskShift = FRAMEBUFFER->blue_mask_shift;
 }
 
+static ST_STATUS
+LimineMemEntryIdx(USIZE Idx, MEMMAP_ENTRY *Result)
+{
+    struct limine_memmap_entry *Entry;
+
+    if (Idx >= MapResp->entry_count) {
+        return STATUS_NOT_FOUND;
+    }
+
+    Entry = MapResp->entries[Idx];
+    Result->Base = Entry->base;
+    Result->Length = Entry->length;
+    Result->Type = Entry->type;
+    return STATUS_SUCCESS;
+}
+
 VOID
 KeBpalLimineInit(BPAL_HANDLE *Handle)
 {
@@ -72,6 +95,7 @@ KeBpalLimineInit(BPAL_HANDLE *Handle)
     LoaderPerfResp = LoaderPerReq.response;
     HHDMResp = HHDMReq.response;
     FbResp = FbReq.response;
+    MapResp = MapReq.response;
 
     DTRACE(
         "slut handed control by %s %s\n",
@@ -91,4 +115,5 @@ KeBpalLimineInit(BPAL_HANDLE *Handle)
 
     BpalInitFramebuffer(Handle);
     Handle->KernelBase = HHDMResp->offset;
+    Handle->MemEntryIdx = LimineMemEntryIdx;
 }