program loading, others

big kernel additions: paging, elf loading, separate kernel and user page allocation
it now properly loads and runs sd0:bin/init.elf
still need to determine which disk was booted from, and start the init on that disk

1 files changed, 0 insertions, 63 deletions

diff --git a/src/kernel/mem.c b/src/kernel/mem.c
deleted file mode 100644
index d3baad3..0000000
--- a/src/kernel/mem.c
+++ /dev/null
@@ -1,63 +0,0 @@
-#include <stdint.h>
-#include "panic.h"
-#include "mem.h"
-
-#define DYNAMIC_START (0x10000000)
-#define DYNAMIC_END   (DYNAMIC_START + 65536 * 4096)
-#define PAGE_TO_ADDR(n) ((void *)(DYNAMIC_START | ((n) << 12)))
-#define ADDR_TO_PAGE(n) (((uint32_t)(n) & ~DYNAMIC_START) >> 12)
-
-#define MMAP_START (0x00010000)
-#define PAGE_USED(n) ((*(uint8_t *)(MMAP_START + (n >> 3)) >> (n & 7)) & 1)
-#define CLEAR_PAGE(n)  *(uint8_t *)(MMAP_START + (n >> 3)) &= ~(1 << (n & 7))
-#define SET_PAGE(n)    *(uint8_t *)(MMAP_START + (n >> 3)) |=   1 << (n & 7)
-
-extern const void kernel_bss_end;
-
-uint16_t pages_left;
-
-void init_mmap() {
-  volatile uint8_t *end_ptr = (uint8_t *)(DYNAMIC_END - 1);
-  uint8_t end_val = *end_ptr;
-  *end_ptr = (uint8_t)~end_val;
-  if (*end_ptr != (uint8_t)~end_val)
-    panic("Not enough memory. Must have at least 512MiB.");
-
-  for (uint32_t *m = (uint32_t *)MMAP_START; m < (uint32_t *)(MMAP_START + (65536 / 8)); ++m)
-    *m = 0;
-
-  uint16_t kernel_bss_pages = (((uint32_t)&kernel_bss_end - DYNAMIC_START - 1) >> 12) + 1;
-  for (uint16_t i = 0; i < kernel_bss_pages; ++i)
-    SET_PAGE(i);
-
-  pages_left = 65536 - kernel_bss_pages;
-}
-
-//very inneficient algorithm, just returns first hole big enough.
-//a smarter algorithm might pick the smallest one available,
-//and go by bytes (or dwords) instead of bits where possible.
-void *allocate_pages(uint16_t n) {
-  uint16_t run = 0;
-  
-  for (uint32_t page = 0; page < 65536; ++page) {
-    if (PAGE_USED(page))
-      run = 0;
-    else if (++run == n) {
-      uint16_t start = page - run + 1;
-      for (uint32_t i = start; i <= page; ++i)
-        SET_PAGE(i);
-      pages_left -= n;
-      return PAGE_TO_ADDR(start);
-    }
-  }
-
-  return 0;
-}
-
-//in the future, change this to go by bytes or dwords instead of bits.
-void free_pages(const void *ptr, uint16_t n) {
-  uint16_t page = ADDR_TO_PAGE(ptr);
-  for (uint32_t i = page; i < page + n; ++i)
-    CLEAR_PAGE(i);
-  pages_left += n;
-}
\ No newline at end of file