feat/kernel: new vallocat API

kernel/src/mm/vmm.c

@@ -101,6 +101,66 @@ void *valloc(vctx_t *ctx, size_t pages, uint64_t flags)
     return (void *)new->start;
 }
 
+void *vallocat(vctx_t *ctx, size_t pages, uint64_t flags, uint64_t phys)
+{
+    if (ctx == NULL || ctx->root == NULL || ctx->pagemap == NULL)
+        return NULL;
+
+    vregion_t *region = ctx->root;
+    vregion_t *new = NULL;
+    vregion_t *last = ctx->root;
+
+    while (region)
+    {
+        if (region->next == NULL || region->start + region->pages < region->next->start)
+        {
+            new = (vregion_t *)palloc(1, true);
+            if (!new)
+                return NULL;
+
+            memset(new, 0, sizeof(vregion_t));
+            new->pages = pages;
+            new->flags = VFLAGS_TO_PFLAGS(flags);
+            new->start = region->start + (region->pages * PAGE_SIZE);
+            new->next = region->next;
+            new->prev = region;
+            region->next = new;
+            for (uint64_t i = 0; i < pages; i++)
+            {
+                uint64_t page = phys + i * PAGE_SIZE;
+                if (page == 0)
+                    return NULL;
+
+                vmap(ctx->pagemap, new->start + i * PAGE_SIZE, page, new->flags);
+            }
+            return (void *)new->start;
+        }
+        region = region->next;
+    }
+
+    new = (vregion_t *)palloc(1, true);
+    if (!new)
+        return NULL;
+
+    memset(new, 0, sizeof(vregion_t));
+    last->next = new;
+    new->prev = last;
+    new->start = last->start + (last->pages * PAGE_SIZE);
+    new->pages = pages;
+    new->flags = VFLAGS_TO_PFLAGS(flags);
+    new->next = NULL;
+
+    for (uint64_t i = 0; i < pages; i++)
+    {
+        uint64_t page = phys + i * PAGE_SIZE;
+        if (page == 0)
+            return NULL;
+
+        vmap(ctx->pagemap, new->start + i * PAGE_SIZE, page, new->flags);
+    }
+    return (void *)new->start;
+}
+
 void vfree(vctx_t *ctx, void *ptr)
 {
     if (ctx == NULL)

kernel/src/mm/vmm.h

@@ -38,6 +38,7 @@ typedef struct vctx
 vctx_t *vinit(uint64_t *pm, uint64_t start);
 void vdestroy(vctx_t *ctx);
 void *valloc(vctx_t *ctx, size_t pages, uint64_t flags);
+void *vallocat(vctx_t *ctx, size_t pages, uint64_t flags, uint64_t phys);
 void vfree(vctx_t *ctx, void *ptr);
 
 #endif // VMM_H

kernel/src/sys/acpi.c

@@ -4,6 +4,7 @@
 #include <lib/string.h>
 #include <util/log.h>
 #include <sys/kpanic.h>
+#include <mm/vmm.h>
 
 static int acpi_uses_xsdt = 0;
 static void *acpi_rsdt_ptr = NULL;
@@ -15,7 +16,9 @@ void acpi_init(void)
         kpanic(NULL, "No RSDP provided");
     }
 
-    acpi_rsdp_t *rsdp = (acpi_rsdp_t *)HIGHER_HALF(rsdp_response->address);
+    acpi_rsdp_t *rsdp = (acpi_rsdp_t *)vallocat(kvm_ctx, 1, VALLOC_RW, rsdp_response->address);
+    log_early("Allocated RSDP at %p", rsdp);
+
     if (memcmp(rsdp->signature, "RSD PTR", 7))
         kpanic(NULL, "Invalid RSDP signature!");