Added init back

19 files changed, 111 insertions, 24 deletions

diff --git a/Makefile b/Makefile
index e0a2ec6..80fe0e5 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ DEBUGFLAGS	!= [ $(RELEASE) ] && echo "-flto -O2" || echo "-O0 -ggdb3 -DDEBUG"
 CFLAGS		= -fno-pie -ffreestanding -nostdlib -std=c17 -Wall -Wextra
 DEPFLAGS	= -MT $@ -MMD -MP -MF $@.d
 
-all: kernel.bin
+all: apos.bin
 
 # default values, overwrite if/when needed
 ARCH		?= riscv
@@ -21,8 +21,9 @@ OBJCOPY		?= objcopy
 OBJCOPY_FLAGS	?= -Obinary --set-section-flags .bss=alloc,load,contents
 
 KERNEL_SOURCES	!= echo common/*.c lib/*.c
-CLEANUP		:= build deps.mk kernel.* apos.bin
+CLEANUP		:= build deps.mk kernel.* init.* apos.bin
 CLEANUP_CMD	:=
+INIT_SOURCES	:=
 
 include arch/$(ARCH)/source.mk
 
@@ -41,20 +42,30 @@ KERN_SIZE	= wc -c kernel.bin | cut -d ' ' -f 1
 KERN_INFO	= sed "s/<KERNEL_SIZE>/$$($(KERN_SIZE))/"
 
 KERNEL_LINK	:= arch/$(ARCH)/conf/kernel-link
+INIT_LINK	:= arch/$(ARCH)/conf/init-link
 
 KERNEL_OBJECTS	!= ./scripts/gen-deps --compile "$(KERNEL_SOURCES)"
+INIT_OBJECTS	!= ./scripts/gen-deps --compile "$(INIT_SOURCES)"
 KERNEL_LD	!= ./scripts/gen-deps --link "$(KERNEL_LINK).S"
+INIT_LD		!= ./scripts/gen-deps --link "$(INIT_LINK).S"
 
 include deps.mk
 
+init.elf: $(INIT_OBJECTS) $(INIT_LD)
+	$(GENELF) -T $(INIT_LD) $(INIT_OBJECTS) -o $@
+
 kernel.elf: $(KERNEL_OBJECTS) $(KERNEL_LD)
 	$(GENELF) -T $(KERNEL_LD) $(KERNEL_OBJECTS) -o $@
 
-$(INIT_LD): kernel.bin
+init.bin: init.elf
+	$(CROSS_COMPILE)$(OBJCOPY) $(OBJCOPY_FLAGS) $< $@
 
 kernel.bin: kernel.elf
 	$(CROSS_COMPILE)$(OBJCOPY) $(OBJCOPY_FLAGS) $< $@
 
+apos.bin: init.bin kernel.bin
+	cat init.bin kernel.bin > apos.bin
+
 clean:
 	$(RM) -r $(CLEANUP)
 
diff --git a/TODO.txt b/TODO.txt
index bbe214d..77cdf70 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -6,3 +6,5 @@
 + Make sure vmap is in 4K increments or whatever
 + Remove/converge convnum and debugging __atoi
 + Create actual init program
+	+ That will need some kind of linking info, say, `place .text etc above
+	0xffffffadsadsad` or whatever. Should be doable, let's see.
diff --git a/arch/riscv/conf/apos.its b/arch/riscv/conf/apos.its
index 1581025..15db4a4 100644
--- a/arch/riscv/conf/apos.its
+++ b/arch/riscv/conf/apos.its
@@ -7,7 +7,7 @@
 	images {
 		kernel {
 			description = "Garbaggio";
-			data = /incbin/("../../../kernel.bin");
+			data = /incbin/("../../../apos.bin");
 			type = "kernel";
 			arch = "riscv";
 			os = "apos";
@@ -21,7 +21,7 @@
 
 		initrd {
 			description = "Gargabbio initrd";
-			data = /incbin/("initrd.txt");
+			data = /incbin/("initrd");
 			type = "ramdisk";
 			arch = "riscv";
 			os = "apos";
diff --git a/arch/riscv/conf/init b/arch/riscv/conf/init
new file mode 100755
index 0000000..06e61e0
--- /dev/null
+++ b/arch/riscv/conf/init
diff --git a/arch/riscv/conf/init-link.S b/arch/riscv/conf/init-link.S
new file mode 100644
index 0000000..642e831
--- /dev/null
+++ b/arch/riscv/conf/init-link.S
@@ -0,0 +1,30 @@
+OUTPUT_ARCH(riscv)
+ENTRY(main)
+
+SECTIONS {
+	. = ABSOLUTE(PM_KERN);
+	__init_start = .;
+
+	/* objcopy only copies these three sections (as far as I'm aware) into the
+	   produces binary, so __init_end should point to the correct location in the
+	   final binary
+	 */
+	.text ALIGN(4K) : AT(0) {
+		*(.init.start)
+		*(.text*);
+	}
+
+	.rodata : {
+		*(.rodata*)
+	}
+
+	.data : {
+		*(.data*)
+	}
+
+	.bss : {
+		*(.bss*) *(COMMON)
+	}
+
+	__init_end = . ;
+}
diff --git a/arch/riscv/conf/initrd b/arch/riscv/conf/initrd
new file mode 100644
index 0000000..8dc931b
--- /dev/null
+++ b/arch/riscv/conf/initrd
diff --git a/arch/riscv/conf/initrd.txt b/arch/riscv/conf/initrd.txt
deleted file mode 100644
index e965047..0000000
--- a/arch/riscv/conf/initrd.txt
+++ /dev/null
@@ -1 +0,0 @@
-Hello
diff --git a/arch/riscv/conf/kernel-link.S b/arch/riscv/conf/kernel-link.S
index bf0ad28..d3b1223 100644
--- a/arch/riscv/conf/kernel-link.S
+++ b/arch/riscv/conf/kernel-link.S
@@ -2,10 +2,10 @@ OUTPUT_ARCH(riscv)
 ENTRY(main)
 
 SECTIONS {
-	. = ABSOLUTE(PM_KERN);
+	. = ABSOLUTE(VM_KERN);
 	__kernel_start = .;
 
-	.text : AT(0) {
+	.text ALIGN(4K) : AT(0) {
 		*(.kernel.start);
 		*(.text*);
 	}
diff --git a/arch/riscv/conf/s.S b/arch/riscv/conf/s.S
new file mode 100644
index 0000000..7b796ce
--- /dev/null
+++ b/arch/riscv/conf/s.S
@@ -0,0 +1,4 @@
+.text
+.global _start
+_start:
+loop: j loop
diff --git a/arch/riscv/include/csr.h b/arch/riscv/include/csr.h
index 70e60bb..bd02b04 100644
--- a/arch/riscv/include/csr.h
+++ b/arch/riscv/include/csr.h
@@ -37,6 +37,9 @@
 #define EXC_LOAD_PAGE_FAULT	13
 #define EXC_STORE_PAGE_FAULT	15
 
+/* status CSR bits */
+#define SSTATUS_SUM		(1 << 18)
+
 /* directly lifted from Linux:/arch/riscv/include/asm/asm.h:9-13 */
 #ifdef __ASSEMBLY__
 #define __ASM_STR(x) x
@@ -50,4 +53,10 @@
 #define csr_write(csr, val)\
 	__asm__ ("csrw " __ASM_STR(csr) ", %0" : : "rK" (val) : "memory")
 
+#define csr_set(csr, val)\
+	__asm__ ("csrs " __ASM_STR(csr) ", %0" : : "rK" (val) : "memory")
+
+#define csr_clear(csr, val)\
+	__asm__ ("csrc " __ASM_STR(csr) ", %0" : : "rK" (val) : "memory")
+
 #endif /* APOS_CSR_H */
diff --git a/arch/riscv/include/vmem.h b/arch/riscv/include/vmem.h
index 2cd3ac7..d17aaf1 100644
--- a/arch/riscv/include/vmem.h
+++ b/arch/riscv/include/vmem.h
@@ -3,7 +3,6 @@
 
 #include <apos/types.h>
 #include <apos/attrs.h>
-#include <apos/pmem.h>
 
 #define VM_V (1 << 0)
 #define VM_R (1 << 1)
@@ -25,11 +24,4 @@ struct __packed vm_branch_t {
 	struct vm_branch_t *leaf[512];
 };
 
-
-void map_vmem(struct vm_branch_t *b,
-		pm_t paddr, vm_t vaddr, uint8_t flags, enum mm_order_t order);
-
-void unmap_vmem(struct vm_branch_t *b,
-		vm_t vaddr, enum mm_order_t order);
-
 #endif /* APOS_RISCV_VMAP_H */
diff --git a/arch/riscv/init/init.c b/arch/riscv/init/init.c
new file mode 100644
index 0000000..d9b32a0
--- /dev/null
+++ b/arch/riscv/init/init.c
@@ -0,0 +1,29 @@
+#include <apos/types.h>
+#include <apos/attrs.h>
+#include <vmem.h>
+#include <csr.h>
+
+/* assume 64 bit for now */
+struct __packed init_vmem {
+	int *leaf[512];
+};
+
+struct init_vmem root_branch;
+
+/* assume Sv48 for now */
+void init_lowmem()
+{
+	size_t flags = VM_V | VM_X | VM_R | VM_W;
+	for(size_t i = 0; i < 512; ++i)
+		root_branch.leaf[i] = (int *)((1UL << 37) * i | flags);
+
+	 csr_write(CSR_SATP, SATP_MODE_Sv48 | ((size_t)&root_branch >> 12));
+}
+
+void __section(".init.start") main(void *fdt)
+{
+	extern char *__init_end;
+	void (*kernel_main)(void *fdt) = (void (*)(void *))(VM_KERN + (size_t)&__init_end);
+	init_lowmem();
+	kernel_main(fdt);
+}
diff --git a/arch/riscv/kernel/main.c b/arch/riscv/kernel/main.c
index 40f0eb6..6c504f8 100644
--- a/arch/riscv/kernel/main.c
+++ b/arch/riscv/kernel/main.c
@@ -259,15 +259,17 @@ static void init_proc(void *fdt, struct vm_branch_t *b)
 	t->pid = 0;
 	t->tid = 0;
 	threads_insert(t);
-	sp_mem_init(&t->sp_r, uvmem_size());
+	sp_mem_init(&t->sp_r, -uvmem_size(), uvmem_size() - 1);
 
 	/* binary itself */
 	size_t sz = align_up(get_init_size(fdt), BASE_PAGE_SIZE);
-	t->bin = alloc_uvmem(t, sz, VM_V | VM_X);
+	t->bin = alloc_uvmem(t, sz, VM_V | VM_X | VM_R | VM_W | VM_U);
 	/* stack */
-	t->stack = alloc_uvmem(t, SZ_2M, VM_V | VM_R | VM_W);
+	t->stack = alloc_uvmem(t, SZ_2M, VM_V | VM_R | VM_W | VM_U);
 	/* if it needs heap, it'll ask for it */
 
+	__asm__ ("sfence.vma" : : : "memory");
+
 	move_init(fdt, (void *)t->bin);
 	jump_to_userspace(t, 0, 0);
 }
@@ -277,6 +279,8 @@ void __main main(void *fdt)
 	init_dbg(fdt);
 	dbg_fdt(fdt);
 
+	/* allow supervisor code to touch user data */
+	csr_set(CSR_SSTATUS, SSTATUS_SUM);
 	struct vm_branch_t *b = init_vmem(fdt);
 	init_mem_blocks();
 	init_irq(fdt);
diff --git a/arch/riscv/kernel/vmem.c b/arch/riscv/kernel/vmem.c
index ffe8731..4cb84a6 100644
--- a/arch/riscv/kernel/vmem.c
+++ b/arch/riscv/kernel/vmem.c
@@ -11,6 +11,11 @@
 #define pte_addr(pte) (pnum_to_paddr(pte_ppn(pte)))
 #define vm_to_index(a, o) (pm_to_index(a, o))
 
+void mod_vmem(struct vm_branch_t *branch, vm_t vaddr, uint8_t flags, enum mm_order_t order)
+{
+	/* todo */
+}
+
 void map_vmem(struct vm_branch_t *branch,
 		pm_t paddr, vm_t vaddr, uint8_t flags, enum mm_order_t order)
 {
diff --git a/arch/riscv/source.mk b/arch/riscv/source.mk
index ecc22bd..0e9a5c3 100644
--- a/arch/riscv/source.mk
+++ b/arch/riscv/source.mk
@@ -1,5 +1,6 @@
 KERNEL_LOCAL	!= echo arch/riscv/kernel/*.[cS]
 KERNEL_SOURCES	+= $(KERNEL_LOCAL)
+INIT_SOURCES	+= arch/riscv/init/init.c
 
 CLEANUP_CMD	:= ./arch/riscv/conf/rmimage.sh
 
diff --git a/common/elf.c b/common/elf.c
index 7531bd1..83411e9 100644
--- a/common/elf.c
+++ b/common/elf.c
@@ -5,5 +5,5 @@ vm_t bin_entry(vm_t bin)
 {
 	struct elf_header *e = (struct elf_header *)bin;
 	/* TODO: check that address points to a valid ELF executable */
-	return (vm_t)e->e_entry;
+	return ((vm_t)e->e_entry) + bin;
 }
diff --git a/common/initrd.c b/common/initrd.c
index f625209..6dd698d 100644
--- a/common/initrd.c
+++ b/common/initrd.c
@@ -75,7 +75,7 @@ pm_t get_initrdbase(void *fdt)
 }
 
 static char init_n[] = "init";
-static size_t init_nlen = ARRAY_SIZE(init_n);
+static size_t init_nlen = ARRAY_SIZE(init_n) - 1; /* ignore trailing NULL */
 
 size_t get_init_size(void *fdt)
 {
diff --git a/common/vmem.c b/common/vmem.c
index 25a8617..6d2b7dc 100644
--- a/common/vmem.c
+++ b/common/vmem.c
@@ -101,10 +101,11 @@ static struct sp_mem *sp_used_insert_region(struct sp_reg_root *r, struct sp_mem
 	return m;
 }
 
-int sp_mem_init(struct sp_reg_root *r, size_t arena_size)
+int sp_mem_init(struct sp_reg_root *r, vm_t start, size_t arena_size)
 {
 	struct sp_mem *m = get_mem_node();
-	m->end = arena_size;
+	m->start = start;
+	m->end = start + arena_size;
 	sp_free_insert_region(r, m);
 
 	return 0;
diff --git a/include/apos/vmem.h b/include/apos/vmem.h
index fe2a76f..daa9d10 100644
--- a/include/apos/vmem.h
+++ b/include/apos/vmem.h
@@ -39,7 +39,7 @@ struct sp_mem {
  */
 
 /* defined by arch */
-int sp_mem_init(struct sp_reg_root *r, size_t nums);
+int sp_mem_init(struct sp_reg_root *r, vm_t start, size_t nums);
 
 vm_t alloc_uvmem(struct tcb *r, size_t s, uint8_t flags);
 void free_uvmem(struct tcb *r, vm_t a);