1 files changed, 76 insertions, 0 deletions
diff --git a/bbl/bbl.c b/bbl/bbl.c
new file mode 100644
index 0000000..cd52fc1
--- /dev/null
+++ b/bbl/bbl.c
@@ -0,0 +1,76 @@
+#include "bbl.h"
+#include "mtrap.h"
+#include "atomic.h"
+#include "vm.h"
+#include "bits.h"
+#include "config.h"
+#include <string.h>
+
+static kernel_elf_info info;
+static volatile int elf_loaded;
+
+static void supervisor_vm_init()
+{
+  uintptr_t highest_va = -first_free_paddr;
+  mem_size = MIN(mem_size, highest_va - info.first_user_vaddr) & -MEGAPAGE_SIZE;
+
+  pte_t* sbi_pt = (pte_t*)(info.first_vaddr_after_user + info.load_offset);
+  memset(sbi_pt, 0, RISCV_PGSIZE);
+  pte_t* middle_pt = (void*)sbi_pt + RISCV_PGSIZE;
+#ifndef __riscv64
+  size_t num_middle_pts = 1;
+  pte_t* root_pt = middle_pt;
+  memset(root_pt, 0, RISCV_PGSIZE);
+#else
+  size_t num_middle_pts = (-info.first_user_vaddr - 1) / GIGAPAGE_SIZE + 1;
+  pte_t* root_pt = (void*)middle_pt + num_middle_pts * RISCV_PGSIZE;
+  memset(middle_pt, 0, (num_middle_pts + 1) * RISCV_PGSIZE);
+  for (size_t i = 0; i < num_middle_pts; i++)
+    root_pt[(1<<RISCV_PGLEVEL_BITS)-num_middle_pts+i] = ptd_create(((uintptr_t)middle_pt >> RISCV_PGSHIFT) + i);
+#endif
+
+  for (uintptr_t vaddr = info.first_user_vaddr, paddr = vaddr + info.load_offset, end = info.first_vaddr_after_user;
+       paddr < mem_size; vaddr += MEGAPAGE_SIZE, paddr += MEGAPAGE_SIZE) {
+    int l2_shift = RISCV_PGLEVEL_BITS + RISCV_PGSHIFT;
+    size_t l2_idx = (info.first_user_vaddr >> l2_shift) & ((1 << RISCV_PGLEVEL_BITS)-1);
+    l2_idx += ((vaddr - info.first_user_vaddr) >> l2_shift);
+    middle_pt[l2_idx] = pte_create(paddr >> RISCV_PGSHIFT, PTE_TYPE_SRWX_GLOBAL);
+  }
+
+  // map SBI at top of vaddr space
+  extern char _sbi_end;
+  uintptr_t num_sbi_pages = ((uintptr_t)&_sbi_end - 1) / RISCV_PGSIZE + 1;
+  assert(num_sbi_pages <= (1 << RISCV_PGLEVEL_BITS));
+  for (uintptr_t i = 0; i < num_sbi_pages; i++) {
+    uintptr_t idx = (1 << RISCV_PGLEVEL_BITS) - num_sbi_pages + i;
+    sbi_pt[idx] = pte_create(i, PTE_TYPE_SRX_GLOBAL);
+  }
+  pte_t* sbi_pte = middle_pt + ((num_middle_pts << RISCV_PGLEVEL_BITS)-1);
+  assert(!*sbi_pte);
+  *sbi_pte = ptd_create((uintptr_t)sbi_pt >> RISCV_PGSHIFT);
+
+  mb();
+  root_page_table = root_pt;
+  write_csr(sptbr, (uintptr_t)root_pt >> RISCV_PGSHIFT);
+}
+
+void boot_loader()
+{
+  extern char _payload_start, _payload_end;
+  load_kernel_elf(&_payload_start, &_payload_end - &_payload_start, &info);
+  supervisor_vm_init();
+#ifdef PK_ENABLE_LOGO
+  print_logo();
+#endif
+  mb();
+  elf_loaded = 1;
+  enter_supervisor_mode((void *)info.entry, 0);
+}
+
+void boot_other_hart()
+{
+  while (!elf_loaded)
+    ;
+  mb();
+  enter_supervisor_mode((void *)info.entry, 0);
+}