From 51cfcb98bde7e78b4817a9060885b25b6c3d354c Mon Sep 17 00:00:00 2001
From: Ada Christine <adachristine18@gmail.com>
Date: Fri, 18 Mar 2022 12:24:48 +0000
Subject: now using clang, native PE UEFI loader image. made an ugly hack to
 get into the shim. it's probably ok.

---
 kc/boot/Makefile    |  3 +++
 kc/core/Makefile    |  2 +-
 kc/defaults.mk      |  8 +++++---
 kc/dynamic_x86_64.c | 13 ++++++++-----
 kc/entry_x86_64.S   |  8 ++++++++
 kc/kc.ld            |  2 +-
 6 files changed, 26 insertions(+), 10 deletions(-)

(limited to 'kc')

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 :
     {
-- 
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