5 files changed, 94 insertions, 4 deletions
diff --git a/include/mercury/kernel/application.hpp b/include/mercury/kernel/application.hpp
new file mode 100644
index 0000000..bc4a763
--- /dev/null
+++ b/include/mercury/kernel/application.hpp
@@ -0,0 +1,72 @@
+#ifndef MERCURY_KERNEL_APPLICATION_HPP
+#define MERCURY_KERNEL_APPLICATION_HPP
+
+#include <mercury/kernel/vfile.hpp>
+#include <cstdint>
+
+namespace mercury::kernel::application {
+
+  enum class app_state {
+    running,
+    paused,
+    zombie
+  };
+
+  struct app_instance {
+
+    app_state state;
+
+    uint64_t *p4;
+    uint64_t *p3;
+    uint64_t *p2;
+
+    bool *p2es_to_free_on_exit;
+
+    uint64_t p4_paddr;
+
+    //set to 0 if none
+    uint64_t framebuffer_vaddr;
+
+    //only valid if state is zombie
+    int exit_code;
+
+    //only valid if state is paused
+    struct {
+      uint64_t rip;
+      uint64_t rsp;
+      //TODO: etc.
+    } saved_regs;
+
+    app_instance();
+    ~app_instance();
+
+    //2MiB page. vaddr and paddr must be aligned, and vaddr in valid range.
+    void map_page(uint64_t vaddr, uint64_t paddr,
+      bool write, bool execute, bool free_pram_on_exit);
+
+    //2MiB pages. returns start of first page.
+    uint64_t get_free_vaddr_pages(uint64_t count);
+
+    void create_stack();
+
+    void set_instruction_pointer(uint64_t vaddr);
+
+    //2MiB pages; only lower half.
+    uint64_t count_mapped_vram_pages();
+
+  };
+
+  extern app_instance *running_app;
+
+  enum class create_app_result {
+    success,
+    device_error,
+    app_corrupt,
+    fs_corrupt
+  };
+
+  create_app_result create_app(const vfile::vfile &file, app_instance *&out);
+
+}
+
+#endif
diff --git a/include/mercury/kernel/framebuffer.hpp b/include/mercury/kernel/framebuffer.hpp
index 5c6ca23..677a42a 100644
--- a/include/mercury/kernel/framebuffer.hpp
+++ b/include/mercury/kernel/framebuffer.hpp
@@ -5,8 +5,10 @@
 
 namespace mercury::kernel::framebuffer {
 
+  extern uint32_t *vaddr;
   extern int width;
   extern int height;
+  extern int dword_pitch;
 
   void init_framebuffer(uint64_t vaddr, uint64_t width, uint64_t height, uint64_t pitch);
 
diff --git a/include/mercury/kernel/paging.hpp b/include/mercury/kernel/paging.hpp
index 4ba5fdf..f6d400a 100644
--- a/include/mercury/kernel/paging.hpp
+++ b/include/mercury/kernel/paging.hpp
@@ -11,27 +11,36 @@ namespace mercury::kernel::paging {
   void mark_all_pram_used();
   void mark_all_vram_free();
 
-  //assumes page-alignment
   void mark_pram_region_free(uint64_t start_addr, uint64_t end_addr);
-  //assumes page-alignment
   void mark_vram_region_used(uint64_t start_addr, uint64_t end_addr);
 
   uint64_t find_unmapped_vram_region(uint64_t page_count);
 
+  uint64_t encode_pte(
+    uint64_t addr, bool user, bool write, bool execute, bool ps);
+
   void init_kernel_page_tables(uint64_t kernel_offset);
 
-  void map_kernel_stack();
+  void map_kernel_stacks();
 
-  //assumes page-alignment
   void map_kernel_page(
     uint64_t paddr, uint64_t vaddr, bool write, bool execute);
 
+  void unmap_kernel_page(uint64_t vaddr);
+
   //maps writable and not executable
   void *map_new_kernel_pages(uint64_t count);
 
+  //maps writable and not executable
+  void map_new_kernel_page(uint64_t &vaddr_out, uint64_t &paddr_out);
+
   uint64_t get_used_vram_page_count();
   uint64_t get_free_pram_page_count();
 
+  extern uint64_t kernel_p4e;
+
+  uint64_t take_2mib_pram_page();
+
 }
 
 #endif
diff --git a/include/mercury/kernel/terminal.hpp b/include/mercury/kernel/terminal.hpp
index 8efbcac..7b2d27a 100644
--- a/include/mercury/kernel/terminal.hpp
+++ b/include/mercury/kernel/terminal.hpp
@@ -28,6 +28,8 @@ namespace mercury::kernel::terminal {
 
   void put_int_decimal(uint64_t n, bool with_commas = true);
 
+  void put_int_hex(uint64_t n, int digits, bool with_dots = true);
+
 }
 
 #endif
diff --git a/include/mercury/kernel/vfile.hpp b/include/mercury/kernel/vfile.hpp
index 43dff96..ce72bb1 100644
--- a/include/mercury/kernel/vfile.hpp
+++ b/include/mercury/kernel/vfile.hpp
@@ -48,6 +48,11 @@ namespace mercury::kernel::vfile {
     //dir_entry.type is assumed to be directory. out must be empty on entry.
     storage::fs_result get_children(utility::vector<vfile> &out) const;
 
+    //assumes file is a regular file and [start, start + length)
+    //is in bounds of file. start and length are in bytes.
+    storage::fs_result read_file(
+      uint64_t start, uint64_t length, void *into) const;
+
   };
 
   //path must be absolute. follows symlinks on all but the last node.