grub2/0008-linuxefi-Use-common-grub_initrd_load.patch

From adf486860fe0d395579be8b01d4fda8b93377768 Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Wed, 8 Jun 2022 16:04:12 +0800
Subject: [PATCH 08/10] linuxefi: Use common grub_initrd_load

By using the common initrd loading routine factored out allows to share between
features like concatenating initramfs component.

For eg.

 initrdefi /initrd-5.16.15-1-default newc:grub.cfg:/grub2/grub.cfg

The file /grub2/grub.cfg read off from root disk will be available to use as
/grub.cfg in the target initramfs loaded by grub.

Signed-off-by: Michael Chang <mchang@suse.com>
---
 grub-core/loader/i386/efi/linux.c | 87 ++++---------------------------
 1 file changed, 10 insertions(+), 77 deletions(-)

--- a/grub-core/loader/i386/efi/linux.c
+++ b/grub-core/loader/i386/efi/linux.c
@@ -30,6 +30,7 @@
 #include <grub/cpu/efi/memory.h>
 #include <grub/tpm.h>
 #include <grub/safemath.h>
+#include <grub/linux.h>
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -146,44 +147,6 @@
   return GRUB_ERR_NONE;
 }
 
-#define BOUNCE_BUFFER_MAX 0x1000000ull
-
-static grub_ssize_t
-read(grub_file_t file, grub_uint8_t *bufp, grub_size_t len)
-{
-  grub_ssize_t bufpos = 0;
-  static grub_size_t bbufsz = 0;
-  static char *bbuf = NULL;
-
-  if (bbufsz == 0)
-    bbufsz = MIN(BOUNCE_BUFFER_MAX, len);
-
-  while (!bbuf && bbufsz)
-    {
-      bbuf = grub_malloc(bbufsz);
-      if (!bbuf)
-	bbufsz >>= 1;
-    }
-  if (!bbuf)
-    grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("cannot allocate bounce buffer"));
-
-  while (bufpos < (long long)len)
-    {
-      grub_ssize_t sz;
-
-      sz = grub_file_read (file, bbuf, MIN(bbufsz, len - bufpos));
-      if (sz < 0)
-	return sz;
-      if (sz == 0)
-	break;
-
-      grub_memcpy(bufp + bufpos, bbuf, sz);
-      bufpos += sz;
-    }
-
-  return bufpos;
-}
-
 #define LOW_U32(val) ((grub_uint32_t)(((grub_addr_t)(val)) & 0xffffffffull))
 #define HIGH_U32(val) ((grub_uint32_t)(((grub_addr_t)(val) >> 32) & 0xffffffffull))
 
@@ -191,10 +154,8 @@
 grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
                  int argc, char *argv[])
 {
-  grub_file_t *files = 0;
-  int i, nfiles = 0;
+  struct grub_linux_initrd_context initrd_ctx = { 0, 0, 0 };
   grub_size_t size = 0;
-  grub_uint8_t *ptr;
 
   if (argc == 0)
     {
@@ -208,24 +169,10 @@
       goto fail;
     }
 
-  files = grub_calloc (argc, sizeof (files[0]));
-  if (!files)
+  if (grub_initrd_init (argc, argv, &initrd_ctx))
     goto fail;
 
-  for (i = 0; i < argc; i++)
-    {
-      files[i] = grub_file_open (argv[i], GRUB_FILE_TYPE_LINUX_INITRD
-			 | GRUB_FILE_TYPE_NO_DECOMPRESS);
-      if (! files[i])
-        goto fail;
-      nfiles++;
-      if (grub_add (size, ALIGN_UP (grub_file_size (files[i]), 4), &size))
-	{
-	  grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected"));
-	  goto fail;
-	}
-    }
-
+  size = grub_get_initrd_size (&initrd_ctx);
   initrd_mem = kernel_alloc(size, N_("can't allocate initrd"));
   if (initrd_mem == NULL)
     goto fail;
@@ -238,30 +185,16 @@
   params->ext_ramdisk_image = HIGH_U32(initrd_mem);
 #endif
 
-  ptr = initrd_mem;
-
-  for (i = 0; i < nfiles; i++)
-    {
-      grub_ssize_t cursize = grub_file_size (files[i]);
-      if (read (files[i], ptr, cursize) != cursize)
-        {
-          if (!grub_errno)
-            grub_error (GRUB_ERR_FILE_READ_ERROR, N_("premature end of file %s"),
-                        argv[i]);
-          goto fail;
-        }
-      ptr += cursize;
-      grub_memset (ptr, 0, ALIGN_UP_OVERHEAD (cursize, 4));
-      ptr += ALIGN_UP_OVERHEAD (cursize, 4);
-    }
+  /* FIXME: Use bounce buffers as many UEFI machines apparently can't DMA
+   * correctly above 4GB
+   */
+  if (grub_initrd_load (&initrd_ctx, initrd_mem))
+    goto fail;
 
   params->ramdisk_size = size;
 
  fail:
-  for (i = 0; i < nfiles; i++)
-    grub_file_close (files[i]);
-  grub_free (files);
-
+  grub_initrd_close (&initrd_ctx);
   if (initrd_mem && grub_errno)
     grub_efi_free_pages((grub_efi_physical_address_t)(grub_addr_t)initrd_mem, BYTES_TO_PAGES(size));