From a9d9db7f4e4a75f6dbda5c31fbbf325eff9d63b4 Mon Sep 17 00:00:00 2001
From: andre4ik3 <andre4ik3@fastmail.com>
Date: Wed, 13 Nov 2024 18:53:25 +0400
Subject: [PATCH] boot: allocate cleanup pages below 4GiB only on x86

Outside of x86, some machines (e.g. Apple silicon, AMD Opteron A1100) have
physical memory mapped above 4GiB, meaning this allocation will fail, causing
the entire boot process to fail on these machines.

This commit makes it so that the below-4GB address space allocation requirement
is only set on x86 platforms, and not on other platforms (that don't have the
specific Linux x86 boot protocol), thereby fixing boot on those that have no
memory mapped below 4GiB in their address space.

Tested on an Apple silicon M1 laptop and an AMD x86_64 desktop tower.

Fixes: #35026

Manual backport of 6e207b370e91e681efb08c497a6c8ad78e3c8d83.
---
 src/boot/efi/boot.c | 9 +++++++++
 src/boot/efi/stub.c | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/boot/efi/boot.c b/src/boot/efi/boot.c
index ecbb4e0509e..8d08fe01f71 100644
--- a/src/boot/efi/boot.c
+++ b/src/boot/efi/boot.c
@@ -2296,11 +2296,20 @@ static EFI_STATUS initrd_prepare(
                         return EFI_OUT_OF_RESOURCES;
         }
 
+#if defined(__i386__) || defined(__x86_64__)
         _cleanup_pages_ Pages pages = xmalloc_pages(
                 AllocateMaxAddress,
                 EfiLoaderData,
                 EFI_SIZE_TO_PAGES(size),
                 UINT32_MAX /* Below 4G boundary. */);
+#else
+        _cleanup_pages_ Pages pages = xmalloc_pages(
+                AllocateAnyPages,
+                EfiLoaderData,
+                EFI_SIZE_TO_PAGES(size),
+                0 /* Ignored. */);
+#endif
+
         uint8_t *p = PHYSICAL_ADDRESS_TO_POINTER(pages.addr);
 
         STRV_FOREACH(i, entry->initrd) {
diff --git a/src/boot/efi/stub.c b/src/boot/efi/stub.c
index 9aa605b7563..0d3df16ef6b 100644
--- a/src/boot/efi/stub.c
+++ b/src/boot/efi/stub.c
@@ -49,11 +49,20 @@ static EFI_STATUS combine_initrds(
                 n += initrd_size;
         }
 
+#if defined(__i386__) || defined(__x86_64__)
         _cleanup_pages_ Pages pages = xmalloc_pages(
                         AllocateMaxAddress,
                         EfiLoaderData,
                         EFI_SIZE_TO_PAGES(n),
                         UINT32_MAX /* Below 4G boundary. */);
+#else
+        _cleanup_pages_ Pages pages = xmalloc_pages(
+                        AllocateAnyPages,
+                        EfiLoaderData,
+                        EFI_SIZE_TO_PAGES(n),
+                        0 /* Ignored. */);
+#endif
+
         uint8_t *p = PHYSICAL_ADDRESS_TO_POINTER(pages.addr);
         for (size_t i = 0; i < n_initrds; i++) {
                 if (!initrds[i])