now using clang, native PE UEFI loader image. made an ugly hack to get

into the shim. it's probably ok.

14 files changed, 127 insertions, 83 deletions

diff --git a/.gitignore b/.gitignore
index 62b87a1..a2bec76 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,4 +6,5 @@
 *.efi
 *.log
 *.kate-swp
+*.pdb
 
diff --git a/README.md b/README.md
index e68d251..203a4aa 100644
--- a/README.md
+++ b/README.md
@@ -9,10 +9,10 @@ whoever is outside my house yelling "comment your code!" i will never comment my
 
 in order to use this you will require the following:
 
-- a gcc cross-compiler targeting x86\_64-elf. instructions [here](https://wiki.osdev.org/GCC_Cross-Compiler)
+- clang 9.0+
 - qemu supporting x86\_64
 - an OVMF installation usable as a firmware for qemu
-- gnu-efi
+- gnu-efi for EFI headers
 
 generally it is only currently possible to build from a POSIX-like system.
 this is not a rule, but i do not currently support any other means
diff --git a/api/loader/efi/shim.h b/api/loader/efi/shim.h
index 0255361..dcdf077 100644
--- a/api/loader/efi/shim.h
+++ b/api/loader/efi/shim.h
@@ -23,11 +23,14 @@ struct efi_loader_image
     UINTN buffer_size;
 };
 
-typedef EFI_STATUS (*efi_image_func)(struct efi_loader_image *image);
-typedef EFI_STATUS (*efi_page_alloc_func)(EFI_MEMORY_TYPE type,
+typedef EFI_STATUS (EFIAPI *efi_image_func)(struct efi_loader_image *image);
+typedef EFI_STATUS (EFIAPI *efi_page_alloc_func)(
+        EFI_MEMORY_TYPE type,
         UINTN size,
         EFI_PHYSICAL_ADDRESS *base);
-typedef EFI_STATUS (*efi_page_free_func)(EFI_PHYSICAL_ADDRESS base, UINTN size);
+typedef EFI_STATUS (EFIAPI *efi_page_free_func)(
+        EFI_PHYSICAL_ADDRESS base, 
+        UINTN size);
 
 struct efi_loader_interface
 {
@@ -42,6 +45,6 @@ struct efi_loader_interface
     efi_image_func image_load;
 };
 
-typedef EFI_STATUS (*efi_shim_entry_func)(struct efi_loader_image *image,
-    struct efi_loader_interface *interface);
+typedef EFI_STATUS
+(__attribute__((sysv_abi)) *efi_shim_entry_func)(struct efi_loader_interface *interface);
 
diff --git a/defaults.mk b/defaults.mk
index 16193f2..2cc7ac1 100644
--- a/defaults.mk
+++ b/defaults.mk
@@ -3,10 +3,10 @@
 ARCH := x86_64
 ABI := elf
 TARGET := $(ARCH)-$(ABI)
-CC := $(TARGET)-gcc
-CXX := $(TARGET)-g++
-AS := $(TARGET)-as
-LD := $(TARGET)-ld
+CC := clang
+CXX := clang++
+AS := clang
+LD := ld.bfd
 OBJCOPY := objcopy
 
 CFLAGS += -ffreestanding -mno-red-zone -ggdb -std=c2x \
@@ -17,6 +17,4 @@ CXXFLAGS += -ffreestanding -mno-red-zone -ggdb \
 	    -Wall -Wextra -Werror -fno-stack-protector
 
 LDFLAGS += -nostdlib
-LIBDIRS += -L$(dir $(shell $(CC) -print-libgcc-file-name))
-LOADLIBES += -lgcc
 
diff --git a/efi.mk b/efi.mk
index 4067e44..60cf1d6 100644
--- a/efi.mk
+++ b/efi.mk
@@ -21,32 +21,7 @@ EFILDSCRIPT := $(EFILIBDIR)/elf_$(GNUEFIARCH)_efi.lds
 CPPFLAGS += -I$(EFIAPIDIR) -I$(EFIAPIDIR)/protocol -I$(EFIAPIDIR)/$(GNUEFIARCH) \
             -DGNU_EFI_USE_MS_ABI -DEFI_CALL_WRAPPER -DEFI_DEBUG
 
-CFLAGS += -fPIC -fshort-wchar -maccumulate-outgoing-args -mno-avx -mno-sse \
-          -mno-mmx -funsigned-char -Wno-pointer-sign
-
-OBJCOPY.efi = $(OBJCOPY) -j .text -j .sdata -j .data -j .dynamic \
-			-j .dynsm -j .rel -j .rela -j .reloc \
-			--target=efi-app-$(GNUEFIARCH) $< $@
-
-OBJCOPY.debug.efi = $(OBJCOPY) -j .text -j .sdata -j .data -j .dynamic \
-				  -j .dynsym -j .rel -j .rela -j .reloc -j .debug_info \
-				  -j .debug_abbrev -j .debug_loc -j .debug_aranges \
-				  -j .debug_line -j .debug_macinfo -j .debug_str \
-				  --target=efi-app-$(GNUEFIARCH) $< $@
-
-LINK._efi.so = $(LD) $(LDFLAGS) -znocombreloc -Bsymbolic -shared --no-undefined \
-               $(LIBDIRS) -L$(EFILIBDIR) -T $(EFILDSCRIPT) \
-               $(filter %.o, $^) -lgnuefi -lefi $(LOADLIBES) -o $@
-
-%.efi: %_efi.so
-	$(OBJCOPY.info)
-	@$(OBJCOPY.efi)
-
-%.debug.efi: %_efi.so
-	$(OBJCOPY.info)
-	@$(OBJCOPY.debug.efi)
-
-%_efi.so: $(EFILDSCRIPT) $(EFICRT)
-	$(LINK.info)
-	@$(LINK._efi.so)
+%.efi: 
+	$(CC.info)
+	@$(CC) $(LDFLAGS) -o $@ $^
 
diff --git a/kc/boot/Makefile b/kc/boot/Makefile
index 297b6df..b90f183 100644
--- a/kc/boot/Makefile
+++ b/kc/boot/Makefile
@@ -8,6 +8,9 @@ TARGET := efi.os
 .DEFAULT: $(TARGET)
 
 CPPFLAGS += -I../../api -I ../api -I../../lib
+
+CFLAGS += -fshort-wchar
+
 OBJS := entry_x86_64.o reloc_x86_64.o dynamic_x86_64.o \
 	kc_main.o elf64.o memcmp.o memcpy.o \
 	memmove.o memset.o loader_paging.o
diff --git a/kc/core/Makefile b/kc/core/Makefile
index 4d373cd..394b2dc 100644
--- a/kc/core/Makefile
+++ b/kc/core/Makefile
@@ -19,7 +19,7 @@ IOBJS :=
 
 # __attribute__((interrupt)) requires -mgeneral-regs-only
 $(GOBJS): CFLAGS += -mgeneral-regs-only
-$(GOBJS): CFLAGS += -mcmodel=small -fPIC
+$(GOBJS): CFLAGS += -mcmodel=small
 
 OBJS := $(SOBJS) $(GOBJS) $(IOBJS)
 DEPS := $(patsubst %.o,%.d,$(OBJS))
diff --git a/kc/defaults.mk b/kc/defaults.mk
index 0b6c4ba..ec6dfd3 100644
--- a/kc/defaults.mk
+++ b/kc/defaults.mk
@@ -1,7 +1,9 @@
 
-LIBDIRS += -L$(dir $(shell $(CC) -print-libgcc-file-name))
 LDSCRIPT := ../kc.ld
+
+CFLAGS += -fPIC -fvisibility=hidden -mgeneral-regs-only
+
 LDFLAGS += -z max-page-size=4096 --export-dynamic -pic \
-	   -z separate-code -pie -Bsymbolic -shared
-LOADLIBES := -lgcc
+	   -z separate-code -pie -Bsymbolic -shared \
+	   -z execstack -g
 
diff --git a/kc/dynamic_x86_64.c b/kc/dynamic_x86_64.c
index 6b7abd7..a573283 100644
--- a/kc/dynamic_x86_64.c
+++ b/kc/dynamic_x86_64.c
@@ -9,10 +9,10 @@ void kc_dynamic_init(void *base, Elf64_Dyn *dyn)
         size_t entsize;
     };
 
-    struct rela reladyn = {NULL,};
-    struct rela relaplt = {NULL,};
+    struct rela reladyn = {NULL, 0, 0};
+    struct rela relaplt = {NULL, 0, 0};
 
-    Elf64_Addr *gotplt;
+    Elf64_Addr *gotplt = NULL;
 
     while (dyn && dyn->d_tag != DT_NULL)
     {
@@ -46,8 +46,11 @@ void kc_dynamic_init(void *base, Elf64_Dyn *dyn)
 
     // peform relocations
     //
-    gotplt[1] = (uintptr_t)NULL;
-    gotplt[2] = (uintptr_t)kc_resolve_symbol;
+    if (gotplt)
+    {
+        gotplt[1] = (uintptr_t)NULL;
+        gotplt[2] = (uintptr_t)kc_resolve_symbol;
+    }
     kc_reloc(base, relaplt.entries, relaplt.size, relaplt.entsize);
     kc_reloc(base, reladyn.entries, reladyn.size, reladyn.entsize);
 }
diff --git a/kc/entry_x86_64.S b/kc/entry_x86_64.S
index 8431044..c426335 100644
--- a/kc/entry_x86_64.S
+++ b/kc/entry_x86_64.S
@@ -6,14 +6,22 @@
 .global kc_entry
 .type kc_entry, @function
 kc_entry:
+    push %rbp
     push %rdi
     push %rsi
+    mov %rsp, %rbp
+    and $-0x10, %rsp
     lea kc_image_base(%rip), %rdi
     lea _DYNAMIC(%rip), %rsi
     call kc_dynamic_init
+    mov %rbp, %rsp
     pop %rsi
     pop %rdi
+    mov %rsp, %rbp
+    and $-0x10, %rsp
     call kc_main
+    mov %rbp, %rsp
+    pop %rbp
     ret
 .size kc_entry, . - kc_entry
 
diff --git a/kc/kc.ld b/kc/kc.ld
index dbce342..97d6a2a 100644
--- a/kc/kc.ld
+++ b/kc/kc.ld
@@ -4,7 +4,7 @@ SECTIONS
 {
     PROVIDE_HIDDEN(kc_image_base = .);
 
-    . = sizeof_headers;
+    . = SIZEOF_HEADERS;
 
     .rela.plt :
     {
diff --git a/loader/Makefile b/loader/Makefile
index 5e1c8ac..d273258 100644
--- a/loader/Makefile
+++ b/loader/Makefile
@@ -4,18 +4,22 @@ include ../efi.mk
 VPATH := ../lib
 
 IMAGE := loader.efi
-BUILD := $(IMAGE) $(IMAGE:.efi=.debug.efi)
 
 CPPFLAGS += -I../api -I../lib
 
-all: $(BUILD)
+CFLAGS += --target=$(GNUEFIARCH)-unknown-windows -fshort-wchar -mno-avx \
+	  -mno-sse -mno-mmx -funsigned-char -Wno-pointer-sign -ggdb
 
-OBJS := main_efi.o elf64.o memcmp.o memmove.o kprintf.o strtoull.o
+LDFLAGS := --target=$(GNUEFIARCH)-unknown-windows -nostdlib -ggdb \
+	   -Wl,-entry:efi_main,-subsystem:efi_application -fuse-ld=lld-link
+
+all: $(IMAGE)
+
+OBJS := main_efi.o elf64.o memcmp.o memmove.o kprintf.o strtoull.o memset.o \
+	memcpy.o
 DEPS := $(OBJS:.o=.d)
 
-IMAGE_SO := $(IMAGE:.efi=_efi.so)
-$(IMAGE_SO): $(OBJS)
-.INTERMEDIATE: $(IMAGE_SO)
+$(IMAGE): $(OBJS)
 
 CLEANLIST := $(wildcard $(BUILD) $(OBJS))
 DCLEANLIST := $(CLEANLIST) $(wildcard $(DEPS))
diff --git a/loader/main_efi.c b/loader/main_efi.c
index 0b7dc3b..3b50c36 100644
--- a/loader/main_efi.c
+++ b/loader/main_efi.c
@@ -32,6 +32,9 @@ static struct efi_loader_image shim_image =
     .path = L"\\adasoft\\sophia\\efi.os"
 };
 
+static CHAR16 *linebuf;
+static CHAR16 *linebuf_ptr;
+
 static VOID *AllocatePool(UINTN size)
 {
     EFI_STATUS status;
@@ -65,16 +68,7 @@ static VOID FreePool(void *block)
     }
 }
 
-static struct efi_loader_interface loader_interface =
-{
-    NULL,
-    NULL,
-    &alloc_page,
-    &free_page,
-    &open_image,
-    &allocate_image,
-    &load_image
-};
+static struct efi_loader_interface loader_interface;
 
 static const CHAR16 *efi_status_strings[] =
 {
@@ -129,14 +123,18 @@ static const CHAR16 *efi_warning_strings[] =
 int kfputc(int c, FILE *f)
 {
     (void)f;
-    CHAR16 s[2] = {0,};
-    EFI_STATUS status;
+    EFI_STATUS status = EFI_SUCCESS;
 
     if (loader_interface.system_table)
     {
         EFI_SIMPLE_TEXT_OUT_PROTOCOL *out = gST->ConOut;
-        s[0] = c;
-        status = out->OutputString(out, s);
+        *linebuf_ptr++ = c;
+        if (((linebuf_ptr - linebuf) == EFI_PAGE_SIZE - 2) || (c == L'\n'))
+        {
+            *linebuf_ptr++ = 0;
+            status = out->OutputString(out, linebuf);
+            linebuf_ptr = linebuf;
+        }
     }
     else
     {
@@ -153,13 +151,54 @@ int kfputc(int c, FILE *f)
 
 EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *system_table)
 {
+    loader_interface = (struct efi_loader_interface){
+        image_handle,
+        system_table,
+        alloc_page,
+        free_page,
+        open_image,
+        allocate_image,
+        load_image
+    };
+
     gST = system_table;
     gBS = system_table->BootServices;
-    loader_interface.image_handle = image_handle;
-    loader_interface.system_table = system_table;
 
     EFI_STATUS status;
 
+    if EFI_ERROR((status = alloc_page(
+                    EfiLoaderData, 
+                    EFI_PAGE_SIZE, 
+                    (EFI_PHYSICAL_ADDRESS *)&linebuf)))
+    {
+        gST->ConOut->OutputString(
+                gST->ConOut,
+                L"error allocating for line buffer");
+        return status;
+    }
+    else
+    {
+        gBS->SetMem(linebuf, EFI_PAGE_SIZE, 0);
+        linebuf_ptr = linebuf;
+    }
+
+    kprintf("loader interface %p\r\n"
+            "image_handle %p\r\n"
+            "system_table %p\r\n"
+            "page_alloc %p\r\n"
+            "page_free %p\r\n"
+            "image_open %p\r\n"
+            "image_alloc %p\r\n"
+            "image_load %p\r\n",
+            &loader_interface,
+            loader_interface.image_handle,
+            loader_interface.system_table,
+            loader_interface.page_alloc,
+            loader_interface.page_free,
+            loader_interface.image_open,
+            loader_interface.image_alloc,
+            loader_interface.image_load);
+
     if (EFI_ERROR((status = open_image(&shim_image))))
     {
         kprintf("error opening shim image: %ls\r\n", 
@@ -214,7 +253,7 @@ EFI_STATUS alloc_page(EFI_MEMORY_TYPE type,
 
 EFI_STATUS free_page(EFI_PHYSICAL_ADDRESS base, UINTN size)
 {
-    return gBS->FreePages(base, size);
+    return gBS->FreePages(base, EFI_SIZE_TO_PAGES(size));
 }
 
 
@@ -304,7 +343,6 @@ EFI_STATUS open_image(struct efi_loader_image *image)
         {
             phdrs_size = ehdr.e_phentsize * ehdr.e_phnum;
             phdrs = AllocatePool(phdrs_size);
-            ASSERT(phdrs);
          }
          else
          {
@@ -366,8 +404,6 @@ static EFI_STATUS read_image(struct efi_loader_image *image,
 
     EFI_STATUS status;
 
-    ASSERT(buffer);
-
     if (!EFI_ERROR((status = image->file->SetPosition(image->file, offset))))
     {
         *buffer = (void *)(image->buffer_base + offset);
@@ -425,12 +461,23 @@ EFI_STATUS load_image(struct efi_loader_image *image)
 
 static EFI_STATUS enter_shim(void)
 {
-    EFI_STATUS status;
+    EFI_STATUS status = EFI_ABORTED;
     Elf64_Ehdr *ehdr = (Elf64_Ehdr *)shim_image.buffer_base;
     kc_entry_func entry;
 
     entry = (kc_entry_func)(shim_image.buffer_base + ehdr->e_entry);
-    status = entry(&loader_interface);
+    kprintf("entering shim @%p\r\n", entry);
+
+    __asm__ volatile
+        (
+         "mov %0, %%rax\n\t"
+         "lea %1, %%rdi\n\t"
+         "call *%%rax\n\t"
+         :
+         : "m"(entry), "m"(loader_interface)
+         : "%rax", "%rdi"
+        );
+
     return status;
 }
 
diff --git a/rules.mk b/rules.mk
index 2115028..756184e 100644
--- a/rules.mk
+++ b/rules.mk
@@ -15,7 +15,7 @@ COMPILE.info = $(info $$(CC) $@)
 
 %.os:
 	$(LINK.info)
-	@$(LINK.os)
+	$(LINK.os)
 
 %.debug.os: %.os
 	$(OBJCOPY) --only-keep-debug $< $@
@@ -23,15 +23,15 @@ COMPILE.info = $(info $$(CC) $@)
 
 %.o: %.c
 	$(COMPILE.info)
-	@$(COMPILE.c) -MMD -MP
+	$(COMPILE.c) -MMD -MP
 
 %.o: %.cpp
 	$(COMPILE.info)
-	@$(COMPILE.cpp) -MMD -MP
+	$(COMPILE.cpp) -MMD -MP
 
 %.o: %.S
 	$(COMPILE.info)
-	@$(COMPILE.S) -MMD -MP
+	$(COMPILE.S) -MMD -MP
 
 clean:
 	$(info $$(RM) $(CLEANLIST))