From: Bibo Mao <maob...@loongson.cn>
Serial port console redirection table can be used for default serial
port selection, like chosen stdout-path selection with FDT method.
With acpi SPCR table added, early debug console can be parsed from
SPCR table with simple kernel parameter earlycon rather than
earlycon=uart,mmio,0x1fe001e0
Signed-off-by: Bibo Mao <maob...@loongson.cn>
Reviewed-by: Song Gao <gaos...@loongson.cn>
Message-Id: <20240907073037.243353-1-maob...@loongson.cn>
Signed-off-by: Song Gao <gaos...@loongson.cn>
---
hw/loongarch/acpi-build.c | 40 +++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/hw/loongarch/acpi-build.c b/hw/loongarch/acpi-build.c
index 04107c84ba..50709bda0f 100644
--- a/hw/loongarch/acpi-build.c
+++ b/hw/loongarch/acpi-build.c
@@ -242,6 +242,44 @@ build_srat(GArray *table_data, BIOSLinker *linker,
MachineState *machine)
acpi_table_end(linker, &table);
}
+/*
+ * Serial Port Console Redirection Table (SPCR)
+ *
https://learn.microsoft.com/en-us/windows-hardware/drivers/serports/serial-port-console-redirection-table
+ */
+static void
+spcr_setup(GArray *table_data, BIOSLinker *linker, MachineState *machine)
+{
+ LoongArchVirtMachineState *lvms;
+ AcpiSpcrData serial = {
+ .interface_type = 0, /* 16550 compatible */
+ .base_addr.id = AML_AS_SYSTEM_MEMORY,
+ .base_addr.width = 32,
+ .base_addr.offset = 0,
+ .base_addr.size = 1,
+ .base_addr.addr = VIRT_UART_BASE,
+ .interrupt_type = 0, /* Interrupt not supported */
+ .pc_interrupt = 0,
+ .interrupt = VIRT_UART_IRQ,
+ .baud_rate = 7, /* 115200 */
+ .parity = 0,
+ .stop_bits = 1,
+ .flow_control = 0,
+ .terminal_type = 3, /* ANSI */
+ .language = 0, /* Language */
+ .pci_device_id = 0xffff, /* not a PCI device*/
+ .pci_vendor_id = 0xffff, /* not a PCI device*/
+ .pci_bus = 0,
+ .pci_device = 0,
+ .pci_function = 0,
+ .pci_flags = 0,
+ .pci_segment = 0,
+ };
+
+ lvms = LOONGARCH_VIRT_MACHINE(machine);
+ build_spcr(table_data, linker, &serial, 2, lvms->oem_id,
+ lvms->oem_table_id);
+}
+
typedef
struct AcpiBuildState {
/* Copy of table in RAM (for patching). */
@@ -484,6 +522,8 @@ static void acpi_build(AcpiBuildTables *tables,
MachineState *machine)
acpi_add_table(table_offsets, tables_blob);
build_srat(tables_blob, tables->linker, machine);
+ acpi_add_table(table_offsets, tables_blob);
+ spcr_setup(tables_blob, tables->linker, machine);
if (machine->numa_state->num_nodes) {
if (machine->numa_state->have_numa_distance) {
--
2.34.1
