Initial commit

kernel/start.c

@@ -0,0 +1,51 @@
+#include "kernel/lib.h"
+#include "kernel/riscv.h"
+#include "kernel/kalloc.h"
+#include "kernel/vm.h"
+#include "kernel/cpu.h"
+
+Cpu cpus[MAX_CPU];
+
+extern uint32_t _bss_start;
+extern uint32_t _bss_end;
+extern uint32_t _ram_end;
+
+void kstrap()
+{
+    panic("kstrap");
+}
+
+void kstart()
+{
+    kalloc_init();
+    kvm_init();
+   
+    panic("kstart: end");
+}
+
+void kinit()
+{
+    // @Todo Initialize CPUs
+    Cpu null_cpu = {0};
+    cpus[0] = null_cpu;
+
+    // Clear the BSS section
+    for (uint32_t* ptr = &_bss_start; ptr < &_bss_end; ++ptr)
+    {
+        *ptr = 0U;
+    }
+
+    w_mideleg(0xFFFF);
+    w_medeleg(0xFFFF);
+
+    w_sstatus(SSTATUS_SPIE | SSTATUS_SPP_S);
+    w_sie(SIE_SEIE);
+    w_sepc(&kstart);
+    w_stvec(&kstrap);
+
+    w_pmpcfg0(PMPCFG_RW | PMPCFG_X | PMPCFG_TOR);
+    w_pmpaddr0(((uint32_t)&_ram_end) >> PMPADDR_SHIFT);
+
+    __asm__ volatile("sret");
+}
+