Re: [edk2-devel] [PATCH v1 6/6] UefiPayloadPkg: LinuxBoot: use a text format for the configuration block.

["Marvin Häuser" <mhaeuser@posteo.de>]

On 21.07.21 15:23, Cheng-Chieh Huang via groups.io wrote:
> From: Trammell Hudson <hudson@trmm.net>
>
> This adds a text command line for the UefiPayloadPkg that uses
> a textual magic number 'LnxBoot1' and a series of white-space
> separated key=value[,value...] pairs for the parameters.
>
> The v1 binary configuration structure is used if it is present instead
> for backwards compatability.
>
> Currently supported text command line arguments are are:
>
> * `serial=baud,base,width,type,hz,pci`
> (only `baud` needs to be specified, the rest have reasonable
> defaults)
>
> * `mem=start,end,type`
> Types are based on `/sys/firmware/memmaps/*/types`:
>      1 == "System RAM"
>      3 == "ACPI Tables"
>      4 == "ACPI Non-volatile Storage"
>      5 == "Reserved"
>
> * `ACPI20=base` pointer to RDSP (from `/sys/firmware/efi/systab`)
>
> * `SMBIOS=base` pointer to the SMBIOS table (also from the EFI table)
>
> Signed-off-by: Cheng-Chieh Huang <chengchieh@google.com>
> ---
>   UefiPayloadPkg/Include/Linuxboot.h             |  17 +-
>   UefiPayloadPkg/Library/LbParseLib/LbParseLib.c | 252 +++++++++++++++++---
>   2 files changed, 230 insertions(+), 39 deletions(-)
>
> diff --git a/UefiPayloadPkg/Include/Linuxboot.h b/UefiPayloadPkg/Include/Linuxboot.h
> index 34ca18069983..56b39b5a09ff 100644
> --- a/UefiPayloadPkg/Include/Linuxboot.h
> +++ b/UefiPayloadPkg/Include/Linuxboot.h
> @@ -24,8 +24,7 @@ typedef struct MemoryMapEntryStruct {
>     UINT32 Type;
>   } MemoryMapEntry;
>   
> -typedef struct UefiPayloadConfigStruct {
> -  UINT64 Version;
> +typedef struct {
>     UINT64 AcpiBase;
>     UINT64 AcpiSize;
>     UINT64 SmbiosBase;
> @@ -33,10 +32,22 @@ typedef struct UefiPayloadConfigStruct {
>     SerialPortConfig SerialConfig;
>     UINT32 NumMemoryMapEntries;
>     MemoryMapEntry MemoryMapEntries[0];
> +} UefiPayloadConfigV1;
> +
> +typedef struct UefiPayloadConfigStruct {
> +  UINT64 Version;
> +  union {
> +    UefiPayloadConfigV1 v1;
> +    struct {
> +      char cmdline[0]; // up to 64 KB
> +    } v2;
> +  } config;
>   } UefiPayloadConfig;
>   #pragma pack()
>   
> -#define UEFI_PAYLOAD_CONFIG_VERSION 1
> +// magic version config is "LnxBoot1"
> +#define UEFI_PAYLOAD_CONFIG_VERSION1 1
> +#define UEFI_PAYLOAD_CONFIG_VERSION2 0x31746f6f42786e4cULL
>   
>   #define LINUXBOOT_MEM_RAM 1
>   #define LINUXBOOT_MEM_DEFAULT 2
> diff --git a/UefiPayloadPkg/Library/LbParseLib/LbParseLib.c b/UefiPayloadPkg/Library/LbParseLib/LbParseLib.c
> index 34bfb6a1073f..5e68091cac91 100644
> --- a/UefiPayloadPkg/Library/LbParseLib/LbParseLib.c
> +++ b/UefiPayloadPkg/Library/LbParseLib/LbParseLib.c
> @@ -1,13 +1,12 @@
>   /** @file
> -  This library will parse the linuxboot table in memory and extract those required
> -  information.
> +  This library will parse the linuxboot table in memory and extract those
> +required information.
>   
>     Copyright (c) 2021, the u-root Authors. All rights reserved.<BR>
>     SPDX-License-Identifier: BSD-2-Clause-Patent
>   
>   **/
>   
> -
>   #include <IndustryStandard/Acpi.h>
>   #include <IndustryStandard/SmBios.h>
>   #include <Library/BaseLib.h>
> @@ -18,17 +17,42 @@
>   #include <Library/PcdLib.h>
>   #include <Linuxboot.h>
>   #include <Uefi/UefiBaseType.h>
> +#include <stdint.h>
> +#include <stdlib.h>
> +//#include <string.h>
> +//#include <ctype.h>
> +
> +#define strncmp(a, b, n) AsciiStrnCmp((a), (b), (n))
> +
> +static uint64_t parse_int(const char* s, char** end) {
> +  UINT64 x;
> +
> +  if (s[0] == '0' && s[1] == 'x')
> +    AsciiStrHexToUint64S(s, end, &x);
> +  else
> +    AsciiStrDecimalToUint64S(s, end, &x);
> +
> +  return x;
> +}
> +
> +static int isspace(const char c) { return c == ' ' || c == '\t' || c == '\n'; }
>   
>   // Retrieve UefiPayloadConfig from Linuxboot's uefiboot
> -UefiPayloadConfig* GetUefiPayLoadConfig() {
> -  UefiPayloadConfig* config =
> +const UefiPayloadConfig* GetUefiPayLoadConfig() {
> +  const UefiPayloadConfig* config =
>         (UefiPayloadConfig*)(UINTN)(PcdGet32(PcdPayloadFdMemBase) - SIZE_64KB);
> -  if (config->Version != UEFI_PAYLOAD_CONFIG_VERSION) {
> -    DEBUG((DEBUG_ERROR, "Expect payload config version: %d, but get %d\n",
> -           UEFI_PAYLOAD_CONFIG_VERSION, config->Version));
> -    CpuDeadLoop ();
> -  }
> -  return config;
> +
> +  if (config->Version == UEFI_PAYLOAD_CONFIG_VERSION1 ||
> +      config->Version == UEFI_PAYLOAD_CONFIG_VERSION2)
> +    return config;
> +
> +  DEBUG((DEBUG_ERROR,
> +         "Expect payload config version %016lx or %016lx, but get %016lx\n",
> +         UEFI_PAYLOAD_CONFIG_VERSION1, UEFI_PAYLOAD_CONFIG_VERSION2,
> +         config->Version));
> +  CpuDeadLoop();
> +  while (1)
> +    ;
>   }
>   
>   // Align the address and add memory rang to MemInfoCallback
> @@ -54,6 +78,57 @@ void AddMemoryRange(IN BL_MEM_INFO_CALLBACK MemInfoCallback, IN UINTN start,
>     MemInfoCallback(&MemoryMap, NULL);
>   }
>   
> +const char* cmdline_next(const char* cmdline, const char** option) {
> +  // at the end of the string, we're done
> +  if (!cmdline || *cmdline == '\0') return NULL;
> +
> +  // skip any leading whitespace
> +  while (isspace(*cmdline)) cmdline++;
> +
> +  // if we've hit the end of the string, we're done
> +  if (*cmdline == '\0') return NULL;
> +
> +  *option = cmdline;
> +
> +  // find the end of this option or the string
> +  while (!isspace(*cmdline) && *cmdline != '\0') cmdline++;
> +
> +  // cmdline points to the whitespace or end of string
> +  return cmdline;
> +}
> +
> +int cmdline_ints(const char* option, uint64_t args[], int max) {
> +  // skip any leading text up to an '='
> +  const char* s = option;
> +  while (1) {
> +    const char c = *s++;
> +    if (c == '=') break;
> +
> +    if (c == '\0' || isspace(c)) {
> +      s = option;
> +      break;
> +    }
> +  }
> +
> +  for (int i = 0; i < max; i++) {
> +    char* end;
> +    args[i] = parse_int(s, &end);
> +
> +    // end of string or end of the option?
> +    if (*end == '\0' || isspace(*end)) return i + 1;
> +
> +    // not separator? signal an error if we have consumed any ints,
> +    // otherwise return 0 saying that none were found
> +    if (*end != ',') return i == 0 ? 0 : -1;
> +
> +    // skip the , and get the next value
> +    s = end + 1;
> +  }
> +
> +  // too many values!
> +  return -1;
> +}
> +
>   /**
>     Acquire the memory information from the linuxboot table in memory.
>   
> @@ -67,20 +142,50 @@ void AddMemoryRange(IN BL_MEM_INFO_CALLBACK MemInfoCallback, IN UINTN start,
>   RETURN_STATUS
>   EFIAPI
>   ParseMemoryInfo(IN BL_MEM_INFO_CALLBACK MemInfoCallback, IN VOID* Params) {
> -  UefiPayloadConfig* config;
> -  int i;
> +  const UefiPayloadConfig* config = GetUefiPayLoadConfig();
> +  if (!config) {
> +    DEBUG(
> +        (DEBUG_ERROR, "ParseMemoryInfo: Could not find UEFI Payload config\n"));
> +    return RETURN_SUCCESS;
> +  }
> +
> +  if (config->Version == UEFI_PAYLOAD_CONFIG_VERSION1) {
> +    const UefiPayloadConfigV1* config1 = &config->config.v1;
> +    DEBUG(
> +        (DEBUG_INFO, "MemoryMap #entries: %d\n", config1->NumMemoryMapEntries));
> +
> +    for (int i = 0; i < config1->NumMemoryMapEntries; i++) {
> +      const MemoryMapEntry* entry = &config1->MemoryMapEntries[i];
> +      DEBUG((DEBUG_INFO, "Start: 0x%lx End: 0x%lx Type:%d\n", entry->Start,
> +             entry->End, entry->Type));
> +      AddMemoryRange(MemInfoCallback, entry->Start, entry->End, entry->Type);
> +    }
> +  } else
>   
> -  config = GetUefiPayLoadConfig();
> +      if (config->Version == UEFI_PAYLOAD_CONFIG_VERSION2) {
> +    const char* cmdline = config->config.v2.cmdline;
> +    const char* option;
> +    uint64_t args[3];
>   
> -  DEBUG((DEBUG_INFO, "MemoryMap #entries: %d\n", config->NumMemoryMapEntries));
> +    // look for the mem=start,end,type
> +    while ((cmdline = cmdline_next(cmdline, &option))) {
> +      if (strncmp(option, "mem=", 4) != 0) continue;
>   
> -  MemoryMapEntry* entry = &config->MemoryMapEntries[0];
> -  for (i = 0; i < config->NumMemoryMapEntries; i++) {
> -    DEBUG((DEBUG_INFO, "Start: 0x%lx End: 0x%lx Type:%d\n", entry->Start,
> -           entry->End, entry->Type));
> -    AddMemoryRange(MemInfoCallback, entry->Start, entry->End, entry->Type);
> -    entry++;
> +      if (cmdline_ints(option, args, 3) != 3) {
> +        DEBUG((DEBUG_ERROR, "Parse error: '%a'\n", option));
> +        continue;
> +      }
> +
> +      const uint64_t start = args[0];
> +      const uint64_t end = args[1];
> +      const uint64_t type = args[2];
> +
> +      DEBUG(
> +          (DEBUG_INFO, "Start: 0x%lx End: 0x%lx Type:%d\n", start, end, type));
> +      AddMemoryRange(MemInfoCallback, start, end, type);
> +    }
>     }
> +
>     return RETURN_SUCCESS;
>   }
>   
> @@ -96,14 +201,52 @@ ParseMemoryInfo(IN BL_MEM_INFO_CALLBACK MemInfoCallback, IN VOID* Params) {
>   RETURN_STATUS
>   EFIAPI
>   ParseSystemTable(OUT SYSTEM_TABLE_INFO* SystemTableInfo) {
> -  UefiPayloadConfig* config;
> +  const UefiPayloadConfig* config = GetUefiPayLoadConfig();
> +  if (!config) {
> +    DEBUG((DEBUG_ERROR,
> +           "ParseSystemTable: Could not find UEFI Payload config\n"));
> +    return RETURN_SUCCESS;
> +  }
>   
> -  config = GetUefiPayLoadConfig();
> -  SystemTableInfo->AcpiTableBase = config->AcpiBase;
> -  SystemTableInfo->AcpiTableSize = config->AcpiSize;
> +  if (config->Version == UEFI_PAYLOAD_CONFIG_VERSION1) {
> +    const UefiPayloadConfigV1* config1 = &config->config.v1;
> +    SystemTableInfo->AcpiTableBase = config1->AcpiBase;
> +    SystemTableInfo->AcpiTableSize = config1->AcpiSize;
>   
> -  SystemTableInfo->SmbiosTableBase = config->SmbiosBase;
> -  SystemTableInfo->SmbiosTableSize = config->SmbiosSize;
> +    SystemTableInfo->SmbiosTableBase = config1->SmbiosBase;
> +    SystemTableInfo->SmbiosTableSize = config1->SmbiosSize;
> +  } else
> +
> +      if (config->Version == UEFI_PAYLOAD_CONFIG_VERSION2) {
> +    const char* cmdline = config->config.v2.cmdline;
> +    const char* option;
> +    uint64_t args[2];
> +
> +    // look for the acpi config
> +    while ((cmdline = cmdline_next(cmdline, &option))) {
> +      if (strncmp(option, "ACPI20=", 7) == 0) {
> +        const int count = cmdline_ints(option, args, 2);
> +        if (count < 0) {
> +          DEBUG((DEBUG_ERROR, "Parse error: '%a'\n", option));
> +          continue;
> +        }
> +
> +        if (count > 0) SystemTableInfo->AcpiTableBase = args[0];
> +        if (count > 1) SystemTableInfo->AcpiTableSize = args[1];
> +      }
> +
> +      if (strncmp(option, "SMBIOS=", 7) == 0) {
> +        const int count = cmdline_ints(option, args, 2);
> +        if (count < 0) {
> +          DEBUG((DEBUG_ERROR, "Parse error: '%a'\n", option));
> +          continue;
> +        }
> +
> +        if (count > 0) SystemTableInfo->SmbiosTableBase = args[0];
> +        if (count > 1) SystemTableInfo->SmbiosTableSize = args[1];
> +      }

Sorry, from only a quick peak, can this not leave {Acpi,Smbios}TableBase 
and {Acpi,Smbios}TableSize undefined entirely, while returning 
RETURN_SUCCESS?
Even if not, it looks kind of odd a command-line argument can change the 
base address without changing the size, is there a documentation of this 
behaviour?
What is the structure supposed to carry if no such arguments are given 
at all?

Thanks for your time!

Best regards,
Marvin

> +    }
> +  }
>   
>     return RETURN_SUCCESS;
>   }
> @@ -120,15 +263,52 @@ ParseSystemTable(OUT SYSTEM_TABLE_INFO* SystemTableInfo) {
>   RETURN_STATUS
>   EFIAPI
>   ParseSerialInfo(OUT SERIAL_PORT_INFO* SerialPortInfo) {
> -  UefiPayloadConfig* config;
> -  config = GetUefiPayLoadConfig();
> -
> -  SerialPortInfo->BaseAddr = config->SerialConfig.BaseAddr;
> -  SerialPortInfo->RegWidth = config->SerialConfig.RegWidth;
> -  SerialPortInfo->Type = config->SerialConfig.Type;
> -  SerialPortInfo->Baud = config->SerialConfig.Baud;
> -  SerialPortInfo->InputHertz = config->SerialConfig.InputHertz;
> -  SerialPortInfo->UartPciAddr = config->SerialConfig.UartPciAddr;
> +  // fill in some reasonable defaults
> +  SerialPortInfo->BaseAddr = 0x3f8;
> +  SerialPortInfo->RegWidth = 1;
> +  SerialPortInfo->Type = 1;  // uefi.SerialPortTypeIO
> +  SerialPortInfo->Baud = 115200;
> +  SerialPortInfo->InputHertz = 1843200;
> +  SerialPortInfo->UartPciAddr = 0;
> +
> +  const UefiPayloadConfig* config = GetUefiPayLoadConfig();
> +  if (!config) {
> +    DEBUG((DEBUG_ERROR, "ParseSerialInfo: using default config\n"));
> +    return RETURN_SUCCESS;
> +  }
> +
> +  if (config->Version == UEFI_PAYLOAD_CONFIG_VERSION1) {
> +    const UefiPayloadConfigV1* config1 = &config->config.v1;
> +    SerialPortInfo->BaseAddr = config1->SerialConfig.BaseAddr;
> +    SerialPortInfo->RegWidth = config1->SerialConfig.RegWidth;
> +    SerialPortInfo->Type = config1->SerialConfig.Type;
> +    SerialPortInfo->Baud = config1->SerialConfig.Baud;
> +    SerialPortInfo->InputHertz = config1->SerialConfig.InputHertz;
> +    SerialPortInfo->UartPciAddr = config1->SerialConfig.UartPciAddr;
> +  } else
> +
> +      if (config->Version == UEFI_PAYLOAD_CONFIG_VERSION2) {
> +    const char* cmdline = config->config.v2.cmdline;
> +    const char* option;
> +    uint64_t args[6] = {};
> +
> +    while ((cmdline = cmdline_next(cmdline, &option))) {
> +      if (strncmp(option, "serial=", 7) != 0) continue;
> +
> +      const int count = cmdline_ints(option, args, 6);
> +      if (count < 0) {
> +        DEBUG((DEBUG_ERROR, "Parse error: %a\n", option));
> +        continue;
> +      }
> +
> +      if (count > 0) SerialPortInfo->Baud = args[0];
> +      if (count > 1) SerialPortInfo->BaseAddr = args[1];
> +      if (count > 2) SerialPortInfo->RegWidth = args[2];
> +      if (count > 3) SerialPortInfo->Type = args[3];
> +      if (count > 4) SerialPortInfo->InputHertz = args[4];
> +      if (count > 5) SerialPortInfo->UartPciAddr = args[5];
> +    }
> +  }
>   
>     return RETURN_SUCCESS;
>   }