[U-Boot] [PATCH 2/2] x86: Install a default e820 table in the __weak install_e820_map()

[Bin Meng]

Hi Simon,

On Tue, Apr 21, 2015 at 9:52 PM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 20 April 2015 at 22:21, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Create a default e820 table with 3 entries which is enough to boot
>> a Linux kernel.
>>
>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>> ---
>>
>>  arch/x86/lib/zimage.c | 29 ++++++++++++++++++++++-------
>>  1 file changed, 22 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/x86/lib/zimage.c b/arch/x86/lib/zimage.c
>> index 566b048..c3f8a73 100644
>> --- a/arch/x86/lib/zimage.c
>> +++ b/arch/x86/lib/zimage.c
>> @@ -25,6 +25,8 @@
>>  #endif
>>  #include <linux/compiler.h>
>>
>> +DECLARE_GLOBAL_DATA_PTR;
>> +
>>  /*
>>   * Memory lay-out:
>>   *
>> @@ -40,16 +42,29 @@
>>
>>  #define COMMAND_LINE_SIZE      2048
>>
>> -unsigned generic_install_e820_map(unsigned max_entries,
>> -                                 struct e820entry *entries)
>> +/*
>> + * Install a default e820 table with 3 entries as follows:
>> + *
>> + *     0x000000-0x0a0000       Useable RAM
>> + *     0x0a0000-0x100000       Reserved for ISA
>> + *     0x100000-gd->ram_size   Useable RAM
>> + */
>> +__weak unsigned install_e820_map(unsigned max_entries,
>> +                                struct e820entry *entries)
>>  {
>> -       return 0;
>> +       entries[0].addr = 0;
>> +       entries[0].size = ISA_START_ADDRESS;
>> +       entries[0].type = E820_RAM;
>> +       entries[1].addr = ISA_START_ADDRESS;
>> +       entries[1].size = ISA_END_ADDRESS - ISA_START_ADDRESS;
>> +       entries[1].type = E820_RESERVED;
>> +       entries[2].addr = ISA_END_ADDRESS;
>> +       entries[2].size = gd->ram_size - ISA_END_ADDRESS;
>> +       entries[2].type = E820_RAM;
>> +
>> +       return 3;
>>  }
>>
>> -unsigned install_e820_map(unsigned max_entries,
>> -                         struct e820entry *entries)
>> -       __attribute__((weak, alias("generic_install_e820_map")));
>> -
>>  static void build_command_line(char *command_line, int auto_boot)
>>  {
>>         char *env_command_line;
>> --
>> 1.8.2.1
>>
>
> Why is this code sitting in zimage.c? Should it be used with bootm also?

Sorry I am not sure I understand your point. setup_zimage() is called
by boot_prep_linux() in bootm.c.

Regards
Bin