Add section loading and entry point execution to UEFI loader

This loads all sections specified by PE header at the correct memory
location, and executes the entry point function. Only the
OutputString function of text output protocol is implemented,
so the only application we can run is hello world.

Test: th
Bug: 294283461
Change-Id: I786bc8b7db9e1c0a6019b8fe4ba5a8c8ab4f2936

lib/uefi/README.md

@@ -0,0 +1,29 @@
+## Build
+
+```
+make qemu-virt-arm64-test
+```
+
+## Run
+
+```
+qemu-system-aarch64 -cpu max -m 512 -smp 1 -machine virt,highmem=off \
+	-kernel qemu-virt-arm64-test/lk.elf \
+	-net none -nographic \
+	-drive if=none,file=lib/uefi/helloworld_aa64.efi,id=blk,format=raw \
+	-device virtio-blk-device,drive=blk
+```
+
+
+Once you see the main console prompt, enter `uefi_load virtio0` to load the hello world UEFI application.
+
+```
+starting app shell
+entering main console loop
+] uefi_load virtio0
+bio_read returns 4096, took 1 msecs (4096000 bytes/sec)
+PE header machine type: aa64
+Valid UEFI application found.
+Entry function located at 0xffff000780067380
+Hello World!
+```

lib/uefi/rules.mk

@@ -2,6 +2,8 @@ LOCAL_DIR := $(GET_LOCAL_DIR)
 
 MODULE := $(LOCAL_DIR)
 
+MODULE_INCLUDES += $(LOCAL_DIR)/include
+
 MODULE_SRCS += \
 	$(LOCAL_DIR)/uefi.cpp \
 

lib/uefi/uefi.cpp

@@ -1,4 +1,5 @@
 #include "defer.h"
+#include "kernel/vm.h"
 #include "pe.h"
 
 #include <lib/bio.h>
@@ -8,10 +9,79 @@
 #include <lk/err.h>
 #include <lk/trace.h>
 #include <platform.h>
+#include <stdio.h>
 #include <string.h>
+#include <sys/types.h>
+
+#include "efi.h"
 
 // ASCII "PE\x0\x0"
-static constexpr uint32_t kPEHeader = 0x4550;
+
+EfiStatus output_string(struct EfiSimpleTextOutputProtocol *self,
+                        char16_t *string) {
+  char buffer[512];
+  size_t i = 0;
+  while (string[i]) {
+    size_t j = 0;
+    for (j = 0; j < sizeof(buffer) - 1 && string[i + j]; j++) {
+      buffer[j] = string[i + j];
+    }
+    i += j;
+    buffer[j] = 0;
+
+    printf("%s", reinterpret_cast<const char *>(buffer));
+  }
+  return SUCCESS;
+}
+
+typedef int (*EfiEntry)(void *handle, struct EfiSystemTable *system);
+
+void *alloc_page(size_t size) {
+  void *vptr{};
+  status_t err = vmm_alloc_contiguous(vmm_get_kernel_aspace(), "uefi_program",
+                                      size, &vptr, 0, 0, 0);
+  if (err) {
+    printf("Failed to allocate memory for uefi program %d\n", err);
+    return nullptr;
+  }
+  return vptr;
+}
+
+int load_sections_and_execute(bdev_t *dev,
+                              const IMAGE_NT_HEADERS64 *pe_header) {
+  const auto file_header = &pe_header->FileHeader;
+  const auto optional_header = &pe_header->OptionalHeader;
+  const auto sections = file_header->NumberOfSections;
+  const auto section_header = reinterpret_cast<const IMAGE_SECTION_HEADER *>(
+      reinterpret_cast<const char *>(pe_header) + sizeof(*pe_header));
+  for (size_t i = 0; i < sections; i++) {
+    if (section_header[i].NumberOfRelocations != 0) {
+      printf("Section %s requires relocation, which is not supported.\n",
+             section_header[i].Name);
+      return -6;
+    }
+  }
+  const auto &last_section = section_header[sections - 1];
+  const auto virtual_size =
+      last_section.VirtualAddress + last_section.Misc.VirtualSize;
+  const auto image_base = reinterpret_cast<char *>(alloc_page(virtual_size));
+  memset(image_base, 0, virtual_size);
+
+  for (size_t i = 0; i < sections; i++) {
+    const auto &section = section_header[i];
+    bio_read(dev, image_base + section.VirtualAddress, section.PointerToRawData,
+             section.SizeOfRawData);
+  }
+  auto entry = reinterpret_cast<EfiEntry>(image_base +
+                                          optional_header->AddressOfEntryPoint);
+  printf("Entry function located at %p\n", entry);
+
+  EfiSystemTable table;
+  EfiSimpleTextOutputProtocol console_out;
+  console_out.output_string = output_string;
+  table.con_out = &console_out;
+  return entry(nullptr, &table);
+}
 
 int load_pe_file(const char *blkdev) {
   bdev_t *dev = bio_open(blkdev);
@@ -58,8 +128,7 @@ int load_pe_file(const char *blkdev) {
            ToString(optional_header->Subsystem));
   }
   printf("Valid UEFI application found.\n");
-
-  return 0;
+  return load_sections_and_execute(dev, pe_header);
 }
 
 int cmd_uefi_load(int argc, const console_cmd_args *argv) {