a good deal of process

doc/design/memory_map.txt

@@ -4,6 +4,8 @@
   0x00 : fat
   0x04 : root directory
   0x08 : kernel
+  0x0c : file handle array
+  0x10 : process array
 0x0600 - 0x1fff : not assigned
 0x2000 - 0x3fff : memory map
   for each word : 1 page

src/kernel/files.c

@@ -0,0 +1,44 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include "files.h"
+
+uint16_t open_file(uint8_t *name) {
+  //TODO
+}
+
+void close_file(uint16_t handle) {
+  FILE_HANDLES[handle].first_sector = 0;
+}
+
+void read_file(uint16_t handle, uint32_t length, void *buffer) {
+  //TODO
+}
+
+void write_file(uint16_t handle, uint32_t length, void *buffer) {
+  //TODO
+}
+
+void seek_file(uint16_t handle, int32_t by) {
+  //TODO
+}
+
+uint32_t get_size(uint16_t handle) {
+  //TODO
+}

src/kernel/files.h

@@ -0,0 +1,40 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include <stdint.h>
+
+#ifndef FILES_H
+#define FILES_H
+
+struct file_handle_info {
+  uint16_t first_sector;
+  uint16_t current_sector;
+  uint8_t *io_buffer;
+  uint32_t position;
+};
+
+#define FILE_HANDLES ((struct file_handle_info *)*(uint32_t *)0x0000050c)
+uint16_t open_file(uint8_t *name);
+void close_file(uint16_t handle);
+void read_file(uint16_t handle, uint32_t length, void *buffer);
+void write_file(uint16_t handle, uint32_t length, void *buffer);
+void seek_file(uint16_t handle, int32_t by);
+uint32_t get_size(uint16_t handle);
+
+#endif

src/kernel/main.c

@@ -18,8 +18,19 @@ OF THIS SOFTWARE.
 */
 
 #include "vga.h"
+#include "files.h"
+#include "mem.h"
+#include "proc.h"
 
 void main(void) {
+  *(uint32_t *)0x0000050c = (uint32_t)allocate_pages(16 * sizeof(struct file_handle_info), 2);
+  for (struct file_handle_info *i = FILE_HANDLES, *l = FILE_HANDLES + 65536; i < l; ++i)
+    i->first_sector = 0;
+
+  *(uint32_t *)0x00000510 = (uint32_t)allocate_pages(16 * sizeof(struct proc_info), 2);
+  for (struct proc_info *i = FILE_HANDLES, *l = FILE_HANDLES + 65536; i < l; ++i)
+    i->memory_start = 0;
+
   put_sz("Welcome to Portland version 0.0.8!\n");
   while (1)
     put_sz("|\b/\b-\b\\\b");

src/kernel/mem.c

@@ -0,0 +1,41 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include "mem.h"
+
+void *allocate_pages(uint16_t n_pages, uint16_t proc_n) {
+  for (uint16_t *i = MMAP, *l = MMAP + 0x1000 - proc_n; ++i; i <= l)
+   outer_for:
+    if (!*i) {
+      for (uint16_t j = 1; j < n_pages; ++j)
+        if (i[j]) {
+          i += j + 1;
+          goto outer_for;
+        }
+      for (uint16_t j = 0; j < n_pages; ++j)
+        i[j] = proc_n;
+      return (void *)((i - MMAP) * 0x1000);
+    }
+  return (void *)0;
+}
+
+void deallocate_pages(void *from, uint16_t n_pages) {
+  for (uint16_t *mb = MMAP + ((uint32_t)from / 0x1000), *l = mb + n_pages; mb < l; ++mb)
+    *mb = 0;
+}

src/kernel/mem.h

@@ -0,0 +1,29 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include <stdint.h>
+
+#ifndef MEM_H
+#define MEM_H
+
+#define MMAP ((uint16_t *)0x00002000)
+void *allocate_pages(uint16_t n_pages, uint16_t proc_n);
+void deallocate_pages(void *from, uint16_t n_pages);
+
+#endif

src/kernel/proc.c

@@ -0,0 +1,43 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include "proc.h"
+#include "mem.h"
+#include "files.h"
+
+uint16_t new_proc(uint8_t *file) {
+  uint16_t handle = open_file(file);
+  if (handle)
+    for (uint16_t id = 3; id; ++id)
+      if (!(PROCS[id].memory_start)) {
+        uint32_t size = get_size(id);
+        void *mem = PROCS[id].memory_start = allocate_pages(PROCS[id].n_pages = (size - 1) / 4096 + 1, id);
+        read_file(handle, size, mem);
+        close_file(handle);
+        //Process file header and make new process
+        return id;
+      }
+  close_file(handle);
+  return 0;
+}
+
+void end_proc(uint16_t id) {
+  deallocate_pages(PROCS[id].memory_start, PROCS[id].n_pages);
+  PROCS[id].memory_start = 0;
+}

src/kernel/proc.h

@@ -0,0 +1,34 @@
+/*
+Copyright 2019 Benji Dial
+
+Permission to use, copy, modify, and/or distribute this
+software for any purpose with or without fee is hereby
+granted, provided that the above copyright notice and this
+permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS
+ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+OF THIS SOFTWARE.
+*/
+
+#include <stdint.h>
+
+#ifndef PROC_H
+#define PROC_H
+
+struct proc_info {
+  void *memory_start;
+  uint16_t n_pages;
+};
+
+#define PROCS ((struct proc_info *)*(uint32_t *)0x00000510)
+uint16_t new_proc(uint8_t *file);
+void end_proc(uint16_t id);
+
+#endif