First jump to virtual memory!

+ Lots of bughunting to do, probably lots of off-by-one and so on
errors, and I make a lot of naive and possibly dangerous assumptions.
But cool start nonetheless. Should also come up with some method of
exchanging data between the init and actual kernel, probably some struct
of some sort. TODO

4 files changed, 47 insertions, 21 deletions

diff --git a/arch/riscv/include/csr.h b/arch/riscv/include/csr.h
index 694000b..5da0882 100644
--- a/arch/riscv/include/csr.h
+++ b/arch/riscv/include/csr.h
@@ -1,8 +1,22 @@
 #ifndef APOS_CSR_H
 #define APOS_CSR_H
 
-#define csr_write(csr, val)
-
 #define SATP_MODE_39 0x8000000000000000
+#define SATP_MODE_48 0x9000000000000000
+
+#define CSR_SATP 0x180
+
+/* directly lifted from Linux:/arch/riscv/include/asm/asm.h:9-13 */
+#ifdef __ASSEMBLY__
+#define __ASM_STR(x) x
+#else
+#define __ASM_STR(x) #x
+#endif
+
+#define csr_read(csr, res)\
+	__asm__ ("csrr %0, " __ASM_STR(csr) : "=r" (res) : : "memory")
+
+#define csr_write(csr, val)\
+	__asm__ ("csrw " __ASM_STR(csr) ", %0" : : "rK" (val) : "memory")
 
 #endif /* APOS_CSR_H */
diff --git a/arch/riscv/include/pages.h b/arch/riscv/include/pages.h
index 82ce6c7..8ca396a 100644
--- a/arch/riscv/include/pages.h
+++ b/arch/riscv/include/pages.h
@@ -2,10 +2,6 @@
 #define APOS_RISCV_PAGES_H
 
 #include <apos/types.h>
-#include <apos/pmem.h>
-
-/* assume riscv64 for now */
-typedef uint64_t pm_t;
 
 #define MM_KPAGE MM_O0
 #define MM_MPAGE MM_O1
@@ -17,4 +13,6 @@ typedef uint64_t pm_t;
 #define MM_GPAGE_SIZE SZ_1G
 #define MM_TPAGE_SIZE SZ_512G
 
+typedef uint64_t paddr_t;
+
 #endif /* APOS_RISCV_PAGES_H */
diff --git a/arch/riscv/include/vmap.h b/arch/riscv/include/vmap.h
deleted file mode 100644
index aee3725..0000000
--- a/arch/riscv/include/vmap.h
+++ /dev/null
@@ -1,15 +0,0 @@
-#ifndef APOS_RISCV_VMAP_H
-#define APOS_RISCV_VMAP_H
-
-#include <apos/sizes.h>
-
-#define VM_V (1 << 0)
-#define VM_R (1 << 1)
-#define VM_W (1 << 2)
-#define VM_X (1 << 3)
-#define VM_U (1 << 4)
-#define VM_G (1 << 5)
-#define VM_A (1 << 6)
-#define VM_D (1 << 7)
-
-#endif /* APOS_RISCV_VMAP_H */
diff --git a/arch/riscv/include/vmem.h b/arch/riscv/include/vmem.h
new file mode 100644
index 0000000..3c27c7b
--- /dev/null
+++ b/arch/riscv/include/vmem.h
@@ -0,0 +1,29 @@
+#ifndef APOS_RISCV_VMAP_H
+#define APOS_RISCV_VMAP_H
+
+#include <apos/sizes.h>
+#include <apos/types.h>
+#include <apos/attrs.h>
+
+#define VM_V (1 << 0)
+#define VM_R (1 << 1)
+#define VM_W (1 << 2)
+#define VM_X (1 << 3)
+#define VM_U (1 << 4)
+#define VM_G (1 << 5)
+#define VM_A (1 << 6)
+#define VM_D (1 << 7)
+
+typedef size_t vaddr_t;
+struct __packed vm_branch_t {
+	struct vm_branch_t *leaf[512];
+};
+
+void map_vmem(struct vm_branch_t *branch,
+		paddr_t paddr, vaddr_t vaddr,
+		uint8_t flags, enum mm_order_t order);
+
+void unmap_vmem(struct vm_branch_t *branch, vaddr_t vaddr, enum mm_order_t order);
+
+
+#endif /* APOS_RISCV_VMAP_H */