From 3fe1a3cfecb8546f90b9a0eb34871b6e786330f8 Mon Sep 17 00:00:00 2001
From: Adrien Bourmault <neox@os-k.eu>
Date: Thu, 9 Jan 2020 23:01:00 +0100
Subject: [PATCH] Dynamic paging functionnal #67

---
 kaleid/kernel/mm/paging.c   | 34 +++++++++++++++----------------
 kaleid/kernel/sh/testcmds.c | 40 +++++++++++++++++++++++++++++++------
 2 files changed, 51 insertions(+), 23 deletions(-)

diff --git a/kaleid/kernel/mm/paging.c b/kaleid/kernel/mm/paging.c
index 4ba948e..c8f581a 100644
--- a/kaleid/kernel/mm/paging.c
+++ b/kaleid/kernel/mm/paging.c
@@ -182,7 +182,7 @@ void MmInitPaging(void)
 //
 // Get a page from an address
 //
-static pte_t MmGetPageDescriptorFromVirtual(void *virtualAddr)
+static pte_t *MmGetPageDescriptorFromVirtual(void *virtualAddr)
 {
     ulong virtAddrPage = (ulong)virtualAddr & ( ~(KPAGESIZE - 1));
 
@@ -197,7 +197,7 @@ static pte_t MmGetPageDescriptorFromVirtual(void *virtualAddr)
     pte_t *pt = (pte_t*)( (ulong)pd[(virtAddrPage / ((ulong)KPAGESIZE * 0x200)) % 512] & ~(KPAGESIZE - 1));
     //DebugLog("pt\t: %p\n", pt);
 
-    ulong page = (ulong)pt[(virtAddrPage / ((ulong)KPAGESIZE)) % 512];
+    pte_t *page = &pt[(virtAddrPage / ((ulong)KPAGESIZE)) % 512];
     //DebugLog("page (with flags): %p\n", page);
 
     return page;
@@ -210,13 +210,13 @@ static pte_t MmGetPageDescriptorFromVirtual(void *virtualAddr)
 void *MmTransVirtToPhyAddr(void* virtualAddr)
 {
     ulong virtAddrPage = (ulong)virtualAddr & ( ~(KPAGESIZE - 1));
-    pte_t page = MmGetPageDescriptorFromVirtual(virtualAddr);
+    pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
 
-    if (page == (page & ~(KPAGESIZE - 1))) {
+    if (*page == (*page & ~(KPAGESIZE - 1))) {
         return NULL;
     }
 
-    return (void*)((page & ~(KPAGESIZE - 1))+ ((ulong)virtualAddr - (ulong)virtAddrPage));
+    return (void*)((*page & ~(KPAGESIZE - 1))+ ((ulong)virtualAddr - (ulong)virtAddrPage));
 }
 
 void *MmTransPhyToVirtAddr(void* physicalAddr)
@@ -229,11 +229,11 @@ void *MmTransPhyToVirtAddr(void* physicalAddr)
 //
 void MmSetPage(void* virtualAddr, ulong flags)
 {
-    pte_t page = MmGetPageDescriptorFromVirtual(virtualAddr);
+    pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
 
-    page |= flags;
+    *page |= flags;
 
-    KeFlushTlbSingle(page);
+    KeFlushTlbSingle(*page);
 }
 
 //
@@ -241,11 +241,11 @@ void MmSetPage(void* virtualAddr, ulong flags)
 //
 void MmUnsetPage(void* virtualAddr, ulong flags)
 {
-    pte_t page = MmGetPageDescriptorFromVirtual(virtualAddr);
+    pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
 
-    page &= (~flags);
+    *page &= (~flags);
 
-    KeFlushTlbSingle(page);
+    KeFlushTlbSingle(*page);
 }
 
 //
@@ -253,11 +253,11 @@ void MmUnsetPage(void* virtualAddr, ulong flags)
 //
 void MmMapPage(void* virtualAddr, void* physicalAddr, ulong flags)
 {
-    pte_t page = MmGetPageDescriptorFromVirtual(virtualAddr);
+    pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
 
-    page = ((ulong)physicalAddr & ~(KPAGESIZE - 1)) | flags;
+    *page = ((ulong)physicalAddr & ~(KPAGESIZE - 1)) | flags;
 
-    KeFlushTlbSingle(page);
+    KeFlushTlbSingle(*page);
 }
 
 //
@@ -265,11 +265,11 @@ void MmMapPage(void* virtualAddr, void* physicalAddr, ulong flags)
 //
 void MmUnmapPage(void* virtualAddr)
 {
-    pte_t page = MmGetPageDescriptorFromVirtual(virtualAddr);
+    pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
 
-    page = 0;
+    *page = 0;
 
-    KeFlushTlbSingle(page);
+    KeFlushTlbSingle(*page);
 }
 
 //-----------
diff --git a/kaleid/kernel/sh/testcmds.c b/kaleid/kernel/sh/testcmds.c
index d0421dd..9fb9b11 100644
--- a/kaleid/kernel/sh/testcmds.c
+++ b/kaleid/kernel/sh/testcmds.c
@@ -204,6 +204,38 @@ error_t CmdPageTranslateVirtToPhy(int argc, char **argv, char *cmdline)
     return EOK;
 }
 
+enum
+{
+    PRESENT      = 1 << 0,
+    READWRITE    = 1 << 1,
+    USERMODE     = 1 << 2,
+    WRITETHR     = 1 << 3,
+    CACHEDIS     = 1 << 4,
+    ACCESSED     = 1 << 5,
+    DIRTY        = 1 << 6,
+    HUGE         = 1 << 7,
+    NX           = 1UL << 63
+};
+
+error_t CmdPageMap(int argc, char **argv, char *cmdline)
+{
+    void *virtual = (void*)atoul(argv[1]);
+    void *physical = (void*)atoul(argv[2]);
+
+    MmMapPage(virtual, physical, PRESENT | READWRITE);
+
+    return EOK;
+}
+
+error_t CmdPageUnmap(int argc, char **argv, char *cmdline)
+{
+    void *virtual = (void*)atoul(argv[1]);
+
+    MmUnmapPage(virtual);
+
+    return EOK;
+}
+
 error_t CmdPageTranslatePhyToVirt(int argc, char **argv, char *cmdline)
 {
      void *address = (void*)atoul(argv[1]);
@@ -222,10 +254,6 @@ error_t CmdPF(int argc, char **argv, char *cmdline)
 {
     ulong *address = (ulong*)(ulong)atoul(argv[1]);
 
-    if (!address) {
-        address = (ulong *)0x80000000;
-    }
-
     KernLog("Provoking Page Fault at %#x\n", address);
 
     KernLog("It contained %#x\n", *address);
@@ -284,8 +312,8 @@ static Command_t testcmdtable[] =
     { "div",        CmdFloatDiv,     "Float div. Usage : div a b. Returns a/b"},
     { "transvtp",   CmdPageTranslateVirtToPhy,  "Translate a virtual to"
                                                   " physical address (paging)"},
-    { "transptv",   CmdPageTranslatePhyToVirt,  "Translate a physical to"
-                                                   " virtual address (paging)"},
+    { "pmap",       CmdPageMap,        "Map a page to given physical addr"    },
+    { "punmap",     CmdPageUnmap,      "Unmap a page"                         },
     { "pf",         CmdPF,             "Provoke a PF. Usage: pfault <address>"},
     { "shell",      CmdShell,          "Start a new shell (nested)",          },
     { "stkov",      CmdStackOverflow,  "Provoke a stack overflow"             },