Introduce support for passing the command line to the efi_multiboot2()
helper, and parse the vga= option if present.
Add support for the 'gfx' and 'current' vga options, ignore the 'keep'
option, and print a warning message about other options not being
currently implemented.
Note that the multboot2 command line string must always be
zero-terminated according to the multiboot2 specification, and hence
there's no need to pass the string size to efi_multiboot2().
Signed-off-by: Roger Pau Monné <roger....@citrix.com>
---
Changes since v3:
- s/last/cur/
- asm style fixes.
- Add note about cmdline always being 0 terminated.
- Also allow \t as valid option separator (as space).
- Expand comment about expected get_option() behavior.
- Always check for valid option terminator.
Changes since v2:
- Do not parse console=.
- Allow width or height to be 0 as long as the gfx- option is well
formed.
Changes since v1:
- Do not return the last occurrence of a command line.
- Rearrange the code for assembly processing of the cmdline and use
lea.
- Merge patches handling console= and vga= together.
---
xen/arch/x86/boot/head.S | 13 +++++-
xen/arch/x86/efi/efi-boot.h | 74 ++++++++++++++++++++++++++++++-
xen/arch/x86/x86_64/asm-offsets.c | 1 +
3 files changed, 84 insertions(+), 4 deletions(-)
diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
index e03f52c75535..1eb829ab419f 100644
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -237,9 +237,10 @@ __efi64_mb2_start:
jmp x86_32_switch
.Lefi_multiboot2_proto:
- /* Zero EFI SystemTable and EFI ImageHandle addresses. */
+ /* Zero EFI SystemTable, EFI ImageHandle addresses and cmdline. */
xor %esi,%esi
xor %edi,%edi
+ xor %edx,%edx
/* Skip Multiboot2 information fixed part. */
lea (MB2_fixed_sizeof+MULTIBOOT2_TAG_ALIGN-1)(%rbx),%ecx
@@ -277,6 +278,13 @@ __efi64_mb2_start:
cmove MB2_efi64_ih(%rcx),%rdi
je .Lefi_mb2_next_tag
+ /* Get command line from Multiboot2 information. */
+ cmpl $MULTIBOOT2_TAG_TYPE_CMDLINE, MB2_tag_type(%rcx)
+ jne .Lno_cmdline
+ lea MB2_tag_string(%rcx), %rdx
+ jmp .Lefi_mb2_next_tag
+.Lno_cmdline:
+
/* Is it the end of Multiboot2 information? */
cmpl $MULTIBOOT2_TAG_TYPE_END,MB2_tag_type(%rcx)
je .Lrun_bs
@@ -340,7 +348,8 @@ __efi64_mb2_start:
/*
* efi_multiboot2() is called according to System V AMD64 ABI:
- * - IN: %rdi - EFI ImageHandle, %rsi - EFI SystemTable.
+ * - IN: %rdi - EFI ImageHandle, %rsi - EFI SystemTable,
+ * %rdx - MB2 cmdline
*/
call efi_multiboot2
diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
index 64c1a02cf10a..4394c7276aa3 100644
--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -795,7 +795,30 @@ static bool __init
efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable)
static void __init efi_arch_flush_dcache_area(const void *vaddr, UINTN size) {
}
-void __init efi_multiboot2(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE
*SystemTable)
+/* Return a pointer to the character after the first occurrence of opt in cmd
*/
+static const char __init *get_option(const char *cmd, const char *opt)
+{
+ const char *s = cmd, *o = NULL;
+
+ if ( !cmd || !opt )
+ return NULL;
+
+ while ( (s = strstr(s, opt)) != NULL )
+ {
+ if ( s == cmd || *(s - 1) == ' ' || *(s - 1) == '\t' )
+ {
+ o = s + strlen(opt);
+ break;
+ }
+
+ s += strlen(opt);
+ }
+
+ return o;
+}
+
+void __init efi_multiboot2(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE
*SystemTable,
+ const char *cmdline)
{
EFI_GRAPHICS_OUTPUT_PROTOCOL *gop;
EFI_HANDLE gop_handle;
@@ -816,7 +839,54 @@ void __init efi_multiboot2(EFI_HANDLE ImageHandle,
EFI_SYSTEM_TABLE *SystemTable
if ( gop )
{
- gop_mode = efi_find_gop_mode(gop, 0, 0, 0);
+ const char *cur = cmdline;
+ unsigned int width = 0, height = 0, depth = 0;
+ bool keep_current = false;
+
+ while ( (cur = get_option(cur, "vga=")) != NULL )
+ {
+#define VALID_TERMINATOR(c) \
+ (*(c) == ' ' || *(c) == '\t' || *(c) == '\0' || *(c) == ',')
+ if ( !strncmp(cur, "gfx-", 4) )
+ {
+ width = simple_strtoul(cur + 4, &cur, 10);
+
+ if ( *cur == 'x' )
+ height = simple_strtoul(cur + 1, &cur, 10);
+ else
+ goto error;
+
+ if ( *cur == 'x' )
+ depth = simple_strtoul(cur + 1, &cur, 10);
+ else
+ goto error;
+
+ if ( !VALID_TERMINATOR(cur) )
+ {
+error:
+ PrintStr(L"Warning: Invalid gfx- option detected.\r\n");
+ width = height = depth = 0;
+ }
+ keep_current = false;
+ }
+ else if ( !strncmp(cur, "current", 7) && VALID_TERMINATOR(cur + 7)
)
+ keep_current = true;
+ else if ( !strncmp(cur, "keep", 4) && VALID_TERMINATOR(cur + 4) )
+ {
+ /* Ignore, handled in later vga= parsing. */
+ }
+ else
+ {
+ /* Fallback to defaults if unimplemented. */
+ width = height = depth = 0;
+ keep_current = false;
+ PrintStr(L"Warning: Cannot use selected vga option.\r\n");
+ }
+#undef VALID_TERMINATOR
+ }
+
+ if ( !keep_current )
+ gop_mode = efi_find_gop_mode(gop, width, height, depth);
efi_arch_edid(gop_handle);
}
diff --git a/xen/arch/x86/x86_64/asm-offsets.c
b/xen/arch/x86/x86_64/asm-offsets.c
index 287dac101ad4..fbd6c54188db 100644
--- a/xen/arch/x86/x86_64/asm-offsets.c
+++ b/xen/arch/x86/x86_64/asm-offsets.c
@@ -175,6 +175,7 @@ void __dummy__(void)
OFFSET(MB2_mem_lower, multiboot2_tag_basic_meminfo_t, mem_lower);
OFFSET(MB2_efi64_st, multiboot2_tag_efi64_t, pointer);
OFFSET(MB2_efi64_ih, multiboot2_tag_efi64_ih_t, pointer);
+ OFFSET(MB2_tag_string, multiboot2_tag_string_t, string);
BLANK();
OFFSET(DOMAIN_vm_assist, struct domain, vm_assist);
--
2.41.0
