From ec1233b4fcd61a8d1eccbf030cede36e9848e06c Mon Sep 17 00:00:00 2001
From: Ada Christine <adachristine18@gmail.com>
Date: Thu, 16 Dec 2021 12:06:04 +0000
Subject: reworking loader

---
 shim/Makefile | 36 ++++++++++++++++++++++++++
 shim/entry.c  | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 shim/shim.ld  | 49 +++++++++++++++++++++++++++++++++++
 3 files changed, 168 insertions(+)
 create mode 100644 shim/Makefile
 create mode 100644 shim/entry.c
 create mode 100644 shim/shim.ld

(limited to 'shim')

diff --git a/shim/Makefile b/shim/Makefile
new file mode 100644
index 0000000..51ec96c
--- /dev/null
+++ b/shim/Makefile
@@ -0,0 +1,36 @@
+include ../defaults.mk
+
+VPATH := ../lib
+
+TARGET := efi.os
+.DEFAULT: $(TARGET)
+
+# EFI API for temporary things
+
+EFIAPIDIR := /usr/local/include/efi
+
+CPPFLAGS += -I../api -I$(EFIAPIDIR) -I$(EFIAPIDIR)/$(ARCH) -I$(EFIAPIDIR)/protocol
+CFLAGS += -Wno-unused-const-variable -Wno-unused-function -fvisibility=hidden \
+	  -g -fshort-wchar -mgeneral-regs-only
+
+LIBDIRS += -L$(dir $(shell $(CC) -print-libgcc-file-name))
+LDSCRIPT := shim.ld
+LDFLAGS += -z max-page-size=4096 --export-dynamic
+LOADLIBES := -lgcc
+
+OBJS := entry.o memcmp.o memcpy.o memmove.o memset.o
+$(OBJS): CFLAGS += -fPIC -fPIE
+
+DEPS := $(patsubst %.o,%.d,$(OBJS))
+
+$(TARGET): $(LDSCRIPT) $(MAKEFILE_LIST)
+$(TARGET): $(OBJS)
+
+CLEANLIST := $(wildcard $(OBJS) $(TARGET)) 
+DCLEANLIST := $(wildcard $(DEPS))
+
+include ../rules.mk
+-include $(DEPS)
+
+.DEFAULT: $(TARGET)
+
diff --git a/shim/entry.c b/shim/entry.c
new file mode 100644
index 0000000..303f582
--- /dev/null
+++ b/shim/entry.c
@@ -0,0 +1,83 @@
+#include <loader/efi/shim.h>
+#include <kernel/memory/range.h>
+
+#include <stdbool.h>
+
+#include "../lib/elf.h"
+
+struct efi_memory_map
+{
+    struct memory_range buffer;
+    UINTN size;
+    UINTN key;
+    UINTN descsize;
+    UINT32 descver;
+};
+
+struct efi_video_data
+{
+    struct memory_range buffer;
+    UINT32 width;
+    UINT32 height;
+    UINT32 pitch;
+    EFI_GRAPHICS_PIXEL_FORMAT format;
+    EFI_PIXEL_BITMASK mask;
+};
+
+struct efi_boot_data
+{
+    struct efi_memory_map memory_map;
+    struct efi_video_data video_data;
+    void *acpi_rsdp;
+    unsigned long acpi_version;
+};
+
+struct efi_loader_image kernel_image =
+{
+    .path = L"\\adasoft\\sophia\\kernel.os"
+};
+
+static struct efi_loader_image *shim_image;
+static struct efi_boot_data boot_data;
+
+EFI_STATUS efi_shim_entry(struct efi_loader_image *image,
+        struct efi_loader_interface *interface)
+{
+    /* 1. load kernel and boot modules into memory
+     * 2. generate page tables for kernel and boot modules
+     * 2. gather boot data, store as type SystemMemoryType
+     * 3. exit boot services
+     * 5. ???????????
+     */
+    
+    EFI_STATUS status;
+
+    if (!image)
+    {
+        return EFI_INVALID_PARAMETER;
+    }
+    else if (!shim_image)
+    {
+        shim_image = image;
+        kernel_image.image_handle = shim_image->image_handle;
+    }
+    else
+    {
+        return EFI_ALREADY_STARTED;
+    }
+
+    if (!EFI_ERROR((status = interface->image_open(&kernel_image))) &&
+            !EFI_ERROR((status = interface->image_alloc(&kernel_image))) &&
+            !EFI_ERROR((status = interface->image_load(&kernel_image))))
+    {
+        (void)boot_data;
+    }
+
+    __asm__ volatile (
+            "cli\n\t"
+            "hlt\n\t"
+            );
+
+    return status;
+}
+
diff --git a/shim/shim.ld b/shim/shim.ld
new file mode 100644
index 0000000..f0643ca
--- /dev/null
+++ b/shim/shim.ld
@@ -0,0 +1,49 @@
+ENTRY(efi_shim_entry)
+
+SECTIONS
+{
+    . = sizeof_headers;
+
+    .rel :
+    {
+        *(.rel.*)
+    }
+
+    .rela :
+    {
+        *(.rela.*)
+    }
+
+    .text : ALIGN(4K)
+    {
+        PROVIDE(_text_begin = .);
+        *(.text)
+        . = ALIGN(4K);
+        PROVIDE(_text_end = .);
+    } =0xcc
+
+    .data :
+    {
+        PROVIDE(_data_begin = .);
+        *(.rodata)
+        *(.data)
+    }
+
+    .data.rel :
+    {
+        *(.data.rel)
+        *(.data.rel.*)
+    }
+
+    .bss :
+    {
+        *(.bss)
+        PROVIDE(_data_end = .);
+    }
+
+    /DISCARD/ :
+    {
+        *(.eh_frame)
+    }
+}
+
-- 
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