Architectural Support: x86_64 (#37)

[lunaix-os.git] / lunaix-os / arch / x86 / boot / i386 / kremap32.c

diff --git a/lunaix-os/arch/x86/boot/i386/kremap32.c b/lunaix-os/arch/x86/boot/i386/kremap32.c
new file mode 100644 (file)
index 0000000..c73c2a3
--- /dev/null
+++ b/lunaix-os/arch/x86/boot/i386/kremap32.c
@@ -0,0 +1,111 @@
+#define __BOOT_CODE__
+
+#include <lunaix/mm/pagetable.h>
+#include <lunaix/compiler.h>
+
+#include <sys/boot/bstage.h>
+#include <sys/mm/mm_defs.h>
+
+bridge_farsym(__kexec_start);
+bridge_farsym(__kexec_end);
+bridge_farsym(__kexec_text_start);
+bridge_farsym(__kexec_text_end);
+
+// define the initial page table layout
+struct kernel_map;
+
+static struct kernel_map kernel_pt __section(".kpg");
+export_symbol(debug, boot, kernel_pt);
+
+struct kernel_map {
+    pte_t l0t[_PAGE_LEVEL_SIZE];
+    pte_t pg_mnt[_PAGE_LEVEL_SIZE];
+
+    struct {
+        pte_t _lft[_PAGE_LEVEL_SIZE];
+    } kernel_lfts[16];
+} align(4);
+
+static void boot_text
+do_remap()
+{
+    struct kernel_map* kpt_pa = (struct kernel_map*)to_kphysical(&kernel_pt);
+    
+    size_t mia_casa_i   = pfn_at(KERNEL_RESIDENT, L0T_SIZE);
+    pte_t* klptep       = (pte_t*) &kpt_pa->l0t[mia_casa_i];
+    pte_t* ktep         = (pte_t*)  kpt_pa->kernel_lfts;    
+    pte_t* boot_l0tep   = (pte_t*)  kpt_pa;
+
+    set_pte(boot_l0tep, pte_mkhuge(mkpte_prot(KERNEL_DATA)));
+
+    // --- 将内核重映射至高半区 ---
+
+    // Hook the kernel reserved LFTs onto L0T
+    pte_t pte = mkpte((ptr_t)ktep, KERNEL_DATA);
+    
+    for (u32_t i = 0; i < KEXEC_RSVD; i++) {
+        pte = pte_setpaddr(pte, (ptr_t)&kpt_pa->kernel_lfts[i]);
+        set_pte(klptep, pte);
+
+        klptep++;
+    }
+
+    // Ensure the size of kernel is within the reservation
+    pfn_t kimg_pagecount = 
+        pfn(__far(__kexec_end) - __far(__kexec_start));
+    if (kimg_pagecount > KEXEC_RSVD * _PAGE_LEVEL_SIZE) {
+        // ERROR: require more pages
+        //  here should do something else other than head into blocking
+        asm("ud2");
+    }
+
+    // Now, map the kernel
+
+    pfn_t kimg_end = pfn(to_kphysical(__far(__kexec_end)));
+    pfn_t i = pfn(to_kphysical(__far(__kexec_text_start)));
+    ktep += i;
+
+    // kernel .text
+    pte = pte_setprot(pte, KERNEL_EXEC);
+    pfn_t ktext_end = pfn(to_kphysical(__far(__kexec_text_end)));
+    for (; i < ktext_end; i++) {
+        pte = pte_setpaddr(pte, page_addr(i));
+        set_pte(ktep, pte);
+
+        ktep++;
+    }
+
+    // all remaining kernel sections
+    pte = pte_setprot(pte, KERNEL_DATA);
+    for (; i < kimg_end; i++) {
+        pte = pte_setpaddr(pte, page_addr(i));
+        set_pte(ktep, pte);
+
+        ktep++;
+    }
+
+    // XXX: Mapping the kernel .rodata section?
+
+    // set mount point
+    pte_t* kmntep = (pte_t*) &kpt_pa->l0t[pfn_at(PG_MOUNT_1, L0T_SIZE)];
+    set_pte(kmntep, mkpte((ptr_t)kpt_pa->pg_mnt, KERNEL_DATA));
+
+    // Build up self-reference
+    int level = (VMS_SELF / L0T_SIZE) & _PAGE_LEVEL_MASK;
+    
+    pte = mkpte_root((ptr_t)kpt_pa, KERNEL_DATA);
+    set_pte(&boot_l0tep[level], pte);
+}
+
+ptr_t boot_text
+remap_kernel()
+{
+    ptr_t kmap_pa = to_kphysical(&kernel_pt);
+    for (size_t i = 0; i < sizeof(kernel_pt); i++) {
+        ((u8_t*)kmap_pa)[i] = 0;
+    }
+
+    do_remap();
+
+    return kmap_pa;
+}
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