From 599138cf9e90876393b3609c144f85bf887b0e12 Mon Sep 17 00:00:00 2001
From: Jianyong Wu <jianyong.wu@arm.com>
Date: Wed, 5 Jul 2023 09:49:30 +0000
Subject: [PATCH] aarch64: Increase size of EFI payload

In order to support the requirements of a larger GRUB binary extend the
size of the memory used for loading the payload. Since the payload
address is hardcoded to a location in RAM below that of where the RHF
binary is loaded increase adjust the ram_min constant to handle that.
This does not require any VMM changes as the load address in the PE
binary will reflect this change.

Fixes: #261

Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
---
 aarch64-unknown-none.ld  | 17 ++++++++++++++---
 src/arch/aarch64/ram64.s | 24 +++++++++++++-----------
 src/main.rs              |  9 +++++++++
 3 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/aarch64-unknown-none.ld b/aarch64-unknown-none.ld
index 31d1b681..2cbab38c 100644
--- a/aarch64-unknown-none.ld
+++ b/aarch64-unknown-none.ld
@@ -4,9 +4,17 @@ ENTRY(ram64_start)
     DRAM:   [0x4000_0000-0xfc00_0000]
     FDT:    [0x4000_0000-0x401f_ffff)
     ACPI:   [0x4020_0000-0x403f_ffff)
-    kernel: [0x4048_0000-]
-   The stack start is at the end of the DRAM region. */
-ram_min = 0x40480000;
+    payload:[0x4040_0000-0x405f_ffff)
+    RHF:    [0x40600000-]
+   Assuming 2MB is enough to load payload.
+   The stack start is at the end of the RHF region. */
+ram_min = 0x40600000;
+
+/* This value must be identical with arch::aarch64::layout::map::dram::KERNEL_START. */
+PAYLOAD_START = 0x40400000;
+
+efi_image_size = rhf_end - ram_min;
+efi_image_offset = ram_min - PAYLOAD_START;
 
 SECTIONS
 {
@@ -41,4 +49,7 @@ SECTIONS
     *(.symtab)
     *(.strtab)
   }
+
+  . = ALIGN(4K);
+  rhf_end = .;
 }
diff --git a/src/arch/aarch64/ram64.s b/src/arch/aarch64/ram64.s
index 93e28e63..53bc055a 100644
--- a/src/arch/aarch64/ram64.s
+++ b/src/arch/aarch64/ram64.s
@@ -3,6 +3,8 @@
 
 .section .text.boot, "ax"
 .global ram64_start
+.global efi_image_size
+.global efi_image_offset
 
 ram64_start:
   /*
@@ -11,18 +13,18 @@ ram64_start:
    *
    * [1] https://docs.kernel.org/arm64/booting.html#call-the-kernel-image
    */
-  add x13, x18, #0x16   /* code0: UEFI "MZ" signature magic instruction */
-  b jump_to_rust        /* code1 */
+  add x13, x18, #0x16     /* code0: UEFI "MZ" signature magic instruction */
+  b jump_to_rust          /* code1 */
 
-  .quad 0               /* text_offset */
-  .quad 0               /* image_size */
-  .quad 0               /* flags */
-  .quad 0               /* res2 */
-  .quad 0               /* res3 */
-  .quad 0               /* res4 */
+  .quad efi_image_offset	/* text_offset */
+  .quad efi_image_size    /* image_size */
+  .quad 0                 /* flags */
+  .quad 0                 /* res2 */
+  .quad 0                 /* res3 */
+  .quad 0                 /* res4 */
 
-  .long 0x644d5241      /* "ARM\x64" magic number */
-  .long 0               /* res5 */
+  .long 0x644d5241        /* "ARM\x64" magic number */
+  .long 0                 /* res5 */
   .align 3
 
 jump_to_rust:
@@ -34,4 +36,4 @@ jump_to_rust:
   mov sp, x30
 
   /* x0: pointer to device tree */
-  b rust64_start
\ No newline at end of file
+  b rust64_start
diff --git a/src/main.rs b/src/main.rs
index ed37984f..4e0b2f05 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -16,6 +16,9 @@ use core::panic::PanicInfo;
 #[cfg(target_arch = "x86_64")]
 use x86_64::instructions::hlt;
 
+#[cfg(target_arch = "aarch64")]
+use crate::arch::aarch64::layout::code_range;
+
 #[macro_use]
 mod serial;
 
@@ -132,6 +135,12 @@ fn boot_from_device(device: &mut block::VirtioBlockDevice, info: &dyn bootinfo::
         }
     };
 
+    #[cfg(target_arch = "aarch64")]
+    if code_range().start < (info.kernel_load_addr() + size) as usize {
+        log!("Error Boot Image is too large");
+        return false;
+    }
+
     log!("Executable loaded");
     efi::efi_exec(entry_addr, load_addr, size, info, &f, device);
     true