fix/kernel: Fixed ACPI tables

kernel/GNUmakefile

@@ -69,6 +69,12 @@ ifeq ($(CONFIG_ENABLE_FLANTERM),y)
     CFLAGS += -I../external/flanterm/ -DFLANTERM_SUPPORT=1
 endif
 
+ifeq ($(CONFIG_LARGE_PAGES),y)
+    CFLAGS += -DLARGE_PAGES=1
+else
+    CFLAGS += -DLARGE_PAGES=0
+endif
+
 EXCLUDE_SRCS := \
     src/mm/heap/ff.c \
     ../external/flanterm/flanterm.c \

kernel/Kconfig

@@ -5,15 +5,15 @@ menu "Build"
         prompt "Build Mode"
         default BUILD_MODE_DEBUG
 
-    config BUILD_MODE_DEBUG
+        config BUILD_MODE_DEBUG
-        bool "Debug"
+            bool "Debug"
-        help
+            help
-          Build with debug symbols and no optimizations.
+              Build with debug symbols and no optimizations.
 
-    config BUILD_MODE_RELEASE
+        config BUILD_MODE_RELEASE
-        bool "Release"
+            bool "Release"
-        help
+            help
-          Build with optimizations and no debug symbols.
+              Build with optimizations and no debug symbols.
 
     endchoice
 endmenu
@@ -23,10 +23,10 @@ menu "Memory"
         prompt "Kernel Heap Algorithm"
         default KERNEL_HEAP_FF
 
-    config KERNEL_HEAP_FF
+        config KERNEL_HEAP_FF
-        bool "First-Fit"
+            bool "First-Fit"
-        help
+            help
-          Use the First-Fit memory allocation algorithm (ff.c).
+              Use the First-Fit memory allocation algorithm (ff.c).
 
     endchoice
 
@@ -52,3 +52,12 @@ menu "Extras"
         help
           Includes support for the Flanterm terminal emulator. Useful for debugging real hardware.
 endmenu
+
+menu "Experimental"
+    comment "These features are experimental and might break the kernel. Don't expect stability."
+
+    config LARGE_PAGES
+        bool "Enable 2M Pages"
+        help
+          Adds support for vmap_large()
+endmenu

kernel/src/arch/paging.c

@@ -112,7 +112,8 @@ uint64_t *pmget(void)
     return (uint64_t *)HIGHER_HALF(cr3);
 }
 
-/* Map virtual to physical address (large), only use during paging init */
+/* Map virtual to physical address (large 2M pages) */
+#if LARGE_PAGES
 bool _supports_large_pages()
 {
     uint32_t eax, ebx, ecx, edx;
@@ -150,6 +151,18 @@ int vmap_large(uint64_t *pagemap, uint64_t virt, uint64_t phys, uint64_t flags)
     __asm__ volatile("invlpg (%0)" ::"r"(virt) : "memory");
     return 0;
 }
+#else  // LARGE_PAGES
+bool _supports_large_pages()
+{
+    log_early("warning: Large pages are disabled in the kernel");
+    return false;
+}
+
+int vmap_large(uint64_t *, uint64_t, uint64_t, uint64_t)
+{
+    return -1;
+}
+#endif // LARGE_PAGES
 
 /* Map virtual to physical address */
 int vmap(uint64_t *pagemap, uint64_t virt, uint64_t phys, uint64_t flags)

kernel/src/boot/emk.h

@@ -35,6 +35,10 @@ extern struct limine_mp_response *mp_response;
 extern struct flanterm_context *ft_ctx;
 #endif // FLANTERM_SUPPORT
 
+#ifndef LARGE_PAGES
+#define LARGE_PAGES 0
+#endif // LARGE_PAGES
+
 #define LOG_SEPARATOR "----------------------------------------"
 
 #endif // EMK_H

kernel/src/mm/vmm.c

@@ -135,7 +135,6 @@ void *vallocat(vctx_t *ctx, size_t pages, uint64_t flags, uint64_t phys)
 
                 vmap(ctx->pagemap, new->start + (i * PAGE_SIZE), page, new->flags);
             }
-            memset((void *)new->start, PAGE_SIZE * pages, 0);
             return (void *)new->start;
         }
         region = region->next;
@@ -161,7 +160,6 @@ void *vallocat(vctx_t *ctx, size_t pages, uint64_t flags, uint64_t phys)
 
         vmap(ctx->pagemap, new->start + (i * PAGE_SIZE), page, new->flags);
     }
-    memset((void *)new->start, PAGE_SIZE * pages, 0);
     return (void *)new->start;
 }
 

kernel/src/sys/acpi.c

@@ -1,28 +1,14 @@
+/* EMK 1.0 Copyright (c) 2025 Piraterna */
 #include <sys/acpi.h>
 #include <boot/emk.h>
 #include <lib/string.h>
 #include <util/log.h>
 #include <sys/kpanic.h>
 #include <mm/vmm.h>
-#include <mm/heap.h>
 
 static int acpi_uses_xsdt = 0;
 static void *acpi_rsdt_ptr = NULL;
 
-void *acpi_vtable(uint64_t phys)
-{
-    acpi_sdt_header_t *tmp = (acpi_sdt_header_t *)vallocat(kvm_ctx, 1, VALLOC_RW, phys);
-    if (!tmp)
-    {
-        kpanic(NULL, "Failed to map first page of ACPI table, got virt: %p", tmp);
-        return NULL;
-    }
-
-    uint32_t full_size = tmp->length;
-    uint32_t page_count = (full_size + 0xFFF) / 0x1000;
-    return vallocat(kvm_ctx, page_count, VALLOC_RW, phys);
-}
-
 void acpi_init(void)
 {
     if (!rsdp_response || !rsdp_response->address)
@@ -31,53 +17,47 @@ void acpi_init(void)
     }
 
     acpi_rsdp_t *rsdp = (acpi_rsdp_t *)vallocat(kvm_ctx, 1, VALLOC_RW, rsdp_response->address);
-    if (memcmp(rsdp->signature, "RSD PTR", 7) != 0)
-        kpanic(NULL, "Invalid RSDP signature! EMK depends on APIC 1.0 or higher");
 
-    if (rsdp->revision >= 2)
+    if (memcmp(rsdp->signature, "RSD PTR", 7) != 0)
+        kpanic(NULL, "Invalid RSDP signature!");
+
+    if (rsdp->revision != 0)
     {
         acpi_uses_xsdt = 1;
         acpi_xsdp_t *xsdp = (acpi_xsdp_t *)rsdp;
-        acpi_rsdt_ptr = acpi_vtable(xsdp->xsdt_address);
+        acpi_rsdt_ptr = (acpi_xsdt_t *)HIGHER_HALF(xsdp->xsdt_address);
-        log_early("Using XSDT");
+        log_early("XSDT found at %p", acpi_rsdt_ptr);
-    }
+        return;
-    else
-    {
-        acpi_uses_xsdt = 0;
-        acpi_rsdt_ptr = acpi_vtable(rsdp->rsdt_address);
-        log_early("Using RSDT");
     }
+
+    acpi_rsdt_ptr = (acpi_rsdt_t *)HIGHER_HALF(rsdp->rsdt_address);
+    log_early("RSDT found at %p", acpi_rsdt_ptr);
 }
 
 void *acpi_find_table(const char *name)
 {
-    if (!acpi_rsdt_ptr || !name)
+    if (!acpi_uses_xsdt)
-        return NULL;
-
-    if (acpi_uses_xsdt)
-    {
-        acpi_xsdt_t *xsdt = (acpi_xsdt_t *)acpi_rsdt_ptr;
-        uint32_t entries = (xsdt->sdt.length - sizeof(xsdt->sdt)) / 8;
-
-        for (uint32_t i = 0; i < entries; i++)
-        {
-            uint64_t phys_addr = ((uint64_t *)xsdt->table)[i];
-            acpi_sdt_header_t *sdt = (acpi_sdt_header_t *)acpi_vtable(phys_addr);
-            if (!memcmp(sdt->signature, name, 4))
-                return sdt;
-        }
-    }
-    else
     {
         acpi_rsdt_t *rsdt = (acpi_rsdt_t *)acpi_rsdt_ptr;
         uint32_t entries = (rsdt->sdt.length - sizeof(rsdt->sdt)) / 4;
-
         for (uint32_t i = 0; i < entries; i++)
         {
-            uint32_t phys_addr = ((uint32_t *)rsdt->table)[i];
+            acpi_sdt_header_t *sdt = (acpi_sdt_header_t *)HIGHER_HALF(*((uint32_t *)rsdt->table + i));
-            acpi_sdt_header_t *sdt = (acpi_sdt_header_t *)acpi_vtable(phys_addr);
             if (!memcmp(sdt->signature, name, 4))
-                return sdt;
+                return (void *)sdt;
+        }
+        return NULL;
+    }
+    acpi_xsdt_t *xsdt = (acpi_xsdt_t *)acpi_rsdt_ptr;
+    log_early("XSDT address: %p", xsdt);
+    uint32_t entries = (xsdt->sdt.length - sizeof(xsdt->sdt)) / 8;
+
+    for (uint32_t i = 0; i < entries; i++)
+    {
+        acpi_sdt_header_t *sdt = (acpi_sdt_header_t *)HIGHER_HALF(*((uint64_t *)xsdt->table + i));
+        if (!memcmp(sdt->signature, name, 4))
+        {
+            return (void *)sdt;
         }
     }