From: Tulio A M Mendes <tadryanom@hotmail.com>
Date: Tue, 10 Feb 2026 04:04:05 +0000 (-0300)
Subject: fix: replace hardcoded 0xC0000000 in slab.c with hal_mm_phys_to_virt()
X-Git-Url: https://projects.tadryanom.me/sitemap.xml?a=commitdiff_plain;h=8300757e23b49af40aa2b01616f412d5220cb5f2;p=AdrOS.git

fix: replace hardcoded 0xC0000000 in slab.c with hal_mm_phys_to_virt()

slab.c used 'base + 0xC0000000U' to convert physical to virtual
addresses, which is x86 higher-half specific. This breaks on ARM,
RISC-V, and MIPS where the kernel virtual base differs.

Add hal_mm_phys_to_virt(), hal_mm_virt_to_phys(), and
hal_mm_kernel_virt_base() to the HAL mm interface with proper
implementations for x86 (0xC0000000 offset) and identity-mapped
stubs for ARM, RISC-V, MIPS.

Passes: make, cppcheck, QEMU smoke test.
---

diff --git a/include/hal/mm.h b/include/hal/mm.h
index 7b89eff..e118b27 100644
--- a/include/hal/mm.h
+++ b/include/hal/mm.h
@@ -7,4 +7,8 @@
 
 int hal_mm_map_physical_range(uintptr_t phys_start, uintptr_t phys_end, uint32_t flags, uintptr_t* out_virt);
 
+uintptr_t hal_mm_phys_to_virt(uintptr_t phys);
+uintptr_t hal_mm_virt_to_phys(uintptr_t virt);
+uintptr_t hal_mm_kernel_virt_base(void);
+
 #endif
diff --git a/src/hal/arm/mm.c b/src/hal/arm/mm.c
index a11e99a..08f91f9 100644
--- a/src/hal/arm/mm.c
+++ b/src/hal/arm/mm.c
@@ -7,3 +7,15 @@ int hal_mm_map_physical_range(uintptr_t phys_start, uintptr_t phys_end, uint32_t
     (void)out_virt;
     return -1;
 }
+
+uintptr_t hal_mm_phys_to_virt(uintptr_t phys) {
+    return phys;
+}
+
+uintptr_t hal_mm_virt_to_phys(uintptr_t virt) {
+    return virt;
+}
+
+uintptr_t hal_mm_kernel_virt_base(void) {
+    return 0;
+}
diff --git a/src/hal/mips/mm.c b/src/hal/mips/mm.c
index a11e99a..08f91f9 100644
--- a/src/hal/mips/mm.c
+++ b/src/hal/mips/mm.c
@@ -7,3 +7,15 @@ int hal_mm_map_physical_range(uintptr_t phys_start, uintptr_t phys_end, uint32_t
     (void)out_virt;
     return -1;
 }
+
+uintptr_t hal_mm_phys_to_virt(uintptr_t phys) {
+    return phys;
+}
+
+uintptr_t hal_mm_virt_to_phys(uintptr_t virt) {
+    return virt;
+}
+
+uintptr_t hal_mm_kernel_virt_base(void) {
+    return 0;
+}
diff --git a/src/hal/riscv/mm.c b/src/hal/riscv/mm.c
index a11e99a..08f91f9 100644
--- a/src/hal/riscv/mm.c
+++ b/src/hal/riscv/mm.c
@@ -7,3 +7,15 @@ int hal_mm_map_physical_range(uintptr_t phys_start, uintptr_t phys_end, uint32_t
     (void)out_virt;
     return -1;
 }
+
+uintptr_t hal_mm_phys_to_virt(uintptr_t phys) {
+    return phys;
+}
+
+uintptr_t hal_mm_virt_to_phys(uintptr_t virt) {
+    return virt;
+}
+
+uintptr_t hal_mm_kernel_virt_base(void) {
+    return 0;
+}
diff --git a/src/hal/x86/mm.c b/src/hal/x86/mm.c
index e9be2ef..158a8ed 100644
--- a/src/hal/x86/mm.c
+++ b/src/hal/x86/mm.c
@@ -31,3 +31,17 @@ int hal_mm_map_physical_range(uintptr_t phys_start, uintptr_t phys_end, uint32_t
     *out_virt = virt_base + (phys_start - phys_start_aligned);
     return 0;
 }
+
+#define X86_KERNEL_VIRT_BASE 0xC0000000U
+
+uintptr_t hal_mm_phys_to_virt(uintptr_t phys) {
+    return phys + X86_KERNEL_VIRT_BASE;
+}
+
+uintptr_t hal_mm_virt_to_phys(uintptr_t virt) {
+    return virt - X86_KERNEL_VIRT_BASE;
+}
+
+uintptr_t hal_mm_kernel_virt_base(void) {
+    return X86_KERNEL_VIRT_BASE;
+}
diff --git a/src/mm/slab.c b/src/mm/slab.c
index 9edd0bd..b103620 100644
--- a/src/mm/slab.c
+++ b/src/mm/slab.c
@@ -1,5 +1,6 @@
 #include "slab.h"
 #include "pmm.h"
+#include "hal/mm.h"
 #include "uart_console.h"
 
 #include <stddef.h>
@@ -35,8 +36,7 @@ static int slab_grow(slab_cache_t* cache) {
      * For now, slab pages come from pmm_alloc_page which returns
      * physical addresses. We need to convert to virtual. */
 
-    /* Use kernel virtual = phys + 0xC0000000 for higher-half */
-    uint8_t* vbase = base + 0xC0000000U;
+    uint8_t* vbase = (uint8_t*)hal_mm_phys_to_virt((uintptr_t)base);
 
     for (uint32_t i = 0; i < cache->objs_per_slab; i++) {
         struct slab_free_node* node = (struct slab_free_node*)(vbase + i * cache->obj_size);