riscv64 boots with clang (sort of)

15 files changed, 40 insertions, 26 deletions

diff --git a/.gitignore b/.gitignore
index faa4724..7c1c102 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,5 +4,6 @@
 *.elf
 *.ld
 include/apos/gen/*
+include/arch/*/gen/*
 deps.mk
 *.img
diff --git a/Makefile b/Makefile
index 45c8b40..2e46774 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,8 @@ CFLAGS		= -ffreestanding -nostdlib -std=c17 -Wall -Wextra -Wvla
 DEPFLAGS	= -MT $@ -MMD -MP -MF $@.d
 LINTFLAGS	= -fsyntax-only
 PREPROCESS	= -E
-LDFLAGS		= -static-libgcc -lgcc
+LDFLAGS		!= [ $(LLVM) ] \
+			|| echo -static-libgcc -lgcc
 
 BUILD		= build
 ARCH_BUILD	= $(BUILD)/arch/$(ARCH)
diff --git a/TODO.txt b/TODO.txt
index 695d48f..dcfe0dd 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -66,3 +66,6 @@ cpu starts its own process manager with a timer of some sort?
 + More const correctness, possibly better assembly but don't count on it.
 + Create some gdb scripts to ease debugging, sort of annoying to have to
 constantly switch between physical and virtual ram
++ Save floating point registers?
++ Come up with a list of requirements for arch to be supported, from what I can
+tell there has to be timers and at least two tiered memory paging.
diff --git a/arch/riscv64/gen/asm-offsets.c b/arch/riscv64/gen/asm-offsets.c
index d78e0ec..6920245 100644
--- a/arch/riscv64/gen/asm-offsets.c
+++ b/arch/riscv64/gen/asm-offsets.c
@@ -3,7 +3,7 @@
 
 /* largely based on linux */
 #define DEFINE(sym, val)                                                       \
-	__asm__ volatile("\n-> " #sym " %0 " #val "\n" ::"i"(val))
+	__asm__ volatile("\n#-> " #sym " %0 " #val "\n" ::"i"(val))
 #define OFFSETOF(m, s) DEFINE(offsetof_##m, offsetof(s, m))
 #define SIZEOF(n, s)   DEFINE(sizeof_##n, sizeof(s))
 
diff --git a/arch/riscv64/gen/source.mk b/arch/riscv64/gen/source.mk
index d291983..596255f 100644
--- a/arch/riscv64/gen/source.mk
+++ b/arch/riscv64/gen/source.mk
@@ -1,8 +1,8 @@
 $(ARCH_SOURCE)/include/gen/asm-offsets.h: $(ARCH_SOURCE)/gen/asm-offsets.c
 	echo "#ifndef APOS_ASM_OFFSETS_H" > $@
 	echo "#define APOS_ASM_OFFSETS_H" >> $@
-	$(COMPILER) $(INCLUDE_FLAGS) -S $< -o - |\
-		awk '($$1 == "->") { print "#define " $$2 " " $$3 }' >> $@
+	$(COMPILER) $(DEPFLAGS) $(INCLUDE_FLAGS) -S $< -o - |\
+		awk '($$1 == "#->") { print "#define " $$2 " " $$3 }' >> $@
 	echo "#endif /* APOS_ASM_OFFSETS_H */" >> $@
 
 CLEANUP	+= $(ARCH_SOURCE)/include/gen/*
diff --git a/arch/riscv64/source.mk b/arch/riscv64/source.mk
index 8c1dfcb..fcb7f69 100644
--- a/arch/riscv64/source.mk
+++ b/arch/riscv64/source.mk
@@ -3,17 +3,17 @@ KERNEL_SOURCES	+= $(KERNEL_LOCAL)
 INIT_SOURCES	+= $(ARCH_SOURCE)/init/*.[cS]
 
 # this doesn't work for rv32, but fine for now */
-CLEANUP_CMD	:= $(ARCH_SOURCE)/conf/rmimage.sh
-
 ARCH_CFLAGS	:= -mcmodel=medany
-ARCH_LDFLAGS	:=
+ARCH_LDFLAGS	:= -fuse-ld=bfd
+
+# slightly hacky but bfd is currently the only compiler that correctly handles
+# riscv relocations, but it doesn't recognise LLVM lto files, so if we're
+# doing an LLVM compilation, remove lto support
+DEBUGFLAGS	!= [ $(LLVM) ] && echo $(DEBUGFLAGS:-flto=) || echo $(DEBUGFLAGS)
 
-# llvm compilation doesn't seem to work, either bfd reads the object files wrong
-# and outputs incorrect symbols or lld handles relocations in a dumb way. Only
-# GCC compiles the kernel correctly at the moment (on RISCV, at least). I'll
-# look into this later, but for now I'll just use GCC. The code does _compile_
-# with clang, it just won't link.
-#LINKFLAGS	:= -fuse-ld=bfd
+# llvm-objcopy is buggy, use gnu tools instead
+# christ, not much LLVM tooling available for RISCV :D
+OBJCOPY		:= $(CROSS_COMPILE)-objcopy
 
 run:
 	$(ARCH_SOURCE)/conf/mkimage.sh
diff --git a/common/main.c b/common/main.c
index 0e33ecc..7168aeb 100644
--- a/common/main.c
+++ b/common/main.c
@@ -1,4 +1,5 @@
 #include <apos/mem_nodes.h>
+#include <apos/timer.h>
 #include <apos/attrs.h>
 #include <apos/proc.h>
 #include <apos/debug.h>
@@ -23,5 +24,6 @@ void __main main(void *fdt)
 	setup_io_dbg(b);
 
 	init_irq(fdt);
+	init_timer(fdt);
 	init_proc(fdt, b);
 }
diff --git a/common/tcb.c b/common/tcb.c
index 326d9ac..bb1bcec 100644
--- a/common/tcb.c
+++ b/common/tcb.c
@@ -57,7 +57,8 @@ struct tcb *new_thread()
 	/* move tcb to top of kernel stack, keeping alignment in check
 	 * (hopefully) */
 	/* TODO: check alignment */
-	struct tcb *t = (struct tcb *)align_down(bottom + __o_size(MM_O0) - sizeof(struct tcb), sizeof(long));
+	struct tcb *t = (struct tcb *)align_down(
+		bottom + __o_size(MM_O0) - sizeof(struct tcb), sizeof(long));
 	memset(t, 0, sizeof(struct tcb));
 
 	id_t tid = __alloc_tid(t);
diff --git a/common/timer.c b/common/timer.c
index 2006a6c..da4fd11 100644
--- a/common/timer.c
+++ b/common/timer.c
@@ -130,3 +130,12 @@ ticks_t nsecs_to_ticks(tunit_t nsecs)
 	ticks_t t = (nsecs * ticks_per_sec) / 1000000000;
 	return t == 0 ? 1 : t;
 }
+
+/* call to this function from exception handlers */
+void update_timers()
+{
+	struct timer *t = newest_timer();
+	remove_timer(t);
+
+	/* TODO: handle timer thread ID */
+}
diff --git a/common/uapi/dispatch.c b/common/uapi/dispatch.c
index 5522c9f..92fa954 100644
--- a/common/uapi/dispatch.c
+++ b/common/uapi/dispatch.c
@@ -10,6 +10,7 @@ static const sys_t syscall_table[] = {
 	[SYS_FREE_MEM] = sys_free_mem,
 
 	/* timers */
+	[SYS_TIMEBASE] = sys_timebase,
 	[SYS_REQ_REL_TIMER] = sys_req_rel_timer,
 	[SYS_REQ_ABS_TIMER] = sys_req_abs_timer,
 	[SYS_FREE_TIMER] = sys_free_timer,
@@ -24,7 +25,6 @@ static const sys_t syscall_table[] = {
 	[SYS_EXEC] = sys_exec,
 	[SYS_SIGNAL] = sys_signal,
 	[SYS_SWITCH] = sys_switch,
-	[SYS_SYNC] = sys_sync,
 
 	/* conf */
 	[SYS_CONF] = sys_conf,
diff --git a/common/uapi/proc.c b/common/uapi/proc.c
index 7c0a69d..a5ce839 100644
--- a/common/uapi/proc.c
+++ b/common/uapi/proc.c
@@ -34,11 +34,3 @@ SYSCALL_DEFINE1(switch)(vm_t pid)
 	/* TODO: switch to process */
 	return 0;
 }
-
-SYSCALL_DEFINE2(sync)(vm_t buf, vm_t size)
-{
-	/* check that only the process manager can use this syscall, otherwise
-	 * just dump process info into the buffer (I guess, not sure if this
-	 * will be quite required */
-	return 0;
-}
diff --git a/common/uapi/timers.c b/common/uapi/timers.c
index 66f6533..5ce596f 100644
--- a/common/uapi/timers.c
+++ b/common/uapi/timers.c
@@ -11,6 +11,11 @@ static ticks_t scaled_ticks(vm_t ticks, vm_t repeat)
 #endif
 }
 
+SYSCALL_DEFINE0(timebase)()
+{
+	return secs_to_ticks(1);
+}
+
 SYSCALL_DEFINE2(req_rel_timer)(vm_t ticks, vm_t repeat)
 {
 	return new_rel_timer(cur_tcb()->tid, scaled_ticks(ticks, repeat));
diff --git a/include/apos/syscalls.h b/include/apos/syscalls.h
index 6f9e312..b8553bc 100644
--- a/include/apos/syscalls.h
+++ b/include/apos/syscalls.h
@@ -15,6 +15,7 @@ enum {
 	SYS_FREE_MEM, /* free memory */
 
 	/* timers */
+	SYS_TIMEBASE,
 	SYS_REQ_REL_TIMER,
 	SYS_REQ_ABS_TIMER,
 	SYS_FREE_TIMER,
@@ -32,7 +33,6 @@ enum {
 	SYS_EXEC, /* execute new binary in process space */
 	SYS_SIGNAL, /* send signal to process (kill etc.) */
 	SYS_SWITCH, /* switch running process */
-	SYS_SYNC, /* used by init process to synchronize running processes, maybe not used */
 
 	/* kernel management */
 	SYS_CONF, /* config system parameters (stack size etc.) */
diff --git a/include/apos/timer.h b/include/apos/timer.h
index e68009a..b506c45 100644
--- a/include/apos/timer.h
+++ b/include/apos/timer.h
@@ -17,7 +17,7 @@ struct timer {
 	ticks_t ticks;
 };
 
-void init_timer();
+void init_timer(const void *fdt);
 
 /* set up timer interrupt ticks from now */
 id_t new_rel_timer(id_t tid, ticks_t ticks);
diff --git a/include/apos/uapi.h b/include/apos/uapi.h
index a6fc2b7..b4a3c6f 100644
--- a/include/apos/uapi.h
+++ b/include/apos/uapi.h
@@ -71,6 +71,7 @@ SYSCALL_DECLARE(req_sharedmem);
 SYSCALL_DECLARE(free_mem);
 
 /* timers */
+SYSCALL_DECLARE(timebase);
 SYSCALL_DECLARE(req_rel_timer);
 SYSCALL_DECLARE(req_abs_timer);
 SYSCALL_DECLARE(free_timer);
@@ -85,7 +86,6 @@ SYSCALL_DECLARE(fork);
 SYSCALL_DECLARE(exec);
 SYSCALL_DECLARE(signal);
 SYSCALL_DECLARE(switch);
-SYSCALL_DECLARE(sync);
 
 /* conf */
 SYSCALL_DECLARE(conf);