[RFC] arm: Defer lookup of machine_type and vet of atags to setup.c

Uncompressing Linux... done, booting the kernel.

Error: unrecognized/unsupported machine ID (r1 = 0x00123456).

Available machine support:

ID (hex) ? ? ? ?NAME
00000183 ? ? ? ?ARM-Versatile PB
0000025e ? ? ? ?ARM-Versatile AB

Please check your kernel config and/or bootloader.

diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index bbecaac..c84b57d 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S

@@ -25,81 +25,6 @@

?* machine ID for example).
?*/
? ? ? ?__HEAD
-__error_a:
-#ifdef CONFIG_DEBUG_LL
- ? ? ? mov ? ? r4, r1 ? ? ? ? ? ? ? ? ? ? ? ? ?@ preserve machine ID
- ? ? ? adr ? ? r0, str_a1
- ? ? ? bl ? ? ?printascii
- ? ? ? mov ? ? r0, r4
- ? ? ? bl ? ? ?printhex8
- ? ? ? adr ? ? r0, str_a2
- ? ? ? bl ? ? ?printascii
- ? ? ? adr ? ? r3, __lookup_machine_type_data
- ? ? ? ldmia ? r3, {r4, r5, r6} ? ? ? ? ? ? ? ?@ get machine desc list
- ? ? ? sub ? ? r4, r3, r4 ? ? ? ? ? ? ? ? ? ? ?@ get offset between virt&phys
- ? ? ? add ? ? r5, r5, r4 ? ? ? ? ? ? ? ? ? ? ?@ convert virt addresses to
- ? ? ? add ? ? r6, r6, r4 ? ? ? ? ? ? ? ? ? ? ?@ physical address space
-1: ? ? ldr ? ? r0, [r5, #MACHINFO_TYPE] ? ? ? ?@ get machine type
- ? ? ? bl ? ? ?printhex8
- ? ? ? mov ? ? r0, #'\t'
- ? ? ? bl ? ? ?printch
- ? ? ? ldr ? ? r0, [r5, #MACHINFO_NAME] ? ? ? ?@ get machine name
- ? ? ? add ? ? r0, r0, r4
- ? ? ? bl ? ? ?printascii
- ? ? ? mov ? ? r0, #'\n'
- ? ? ? bl ? ? ?printch
- ? ? ? add ? ? r5, r5, #SIZEOF_MACHINE_DESC ? ?@ next machine_desc
- ? ? ? cmp ? ? r5, r6
- ? ? ? blo ? ? 1b
- ? ? ? adr ? ? r0, str_a3
- ? ? ? bl ? ? ?printascii
- ? ? ? b ? ? ? __error
-ENDPROC(__error_a)
-
-str_a1: ? ? ? ?.asciz ?"\nError: unrecognized/unsupported machine ID (r1 = 0x"
-str_a2: ? ? ? ?.asciz ?").\n\nAvailable machine support:\n\nID (hex)\tNAME\n"
-str_a3: ? ? ? ?.asciz ?"\nPlease check your kernel config and/or bootloader.\n"
- ? ? ? .align
-#endif
-
-/*
- * Lookup machine architecture in the linker-build list of architectures.
- * Note that we can't use the absolute addresses for the __arch_info
- * lists since we aren't running with the MMU on (and therefore, we are
- * not in the correct address space). ?We have to calculate the offset.
- *
- * ?r1 = machine architecture number
- * Returns:
- * ?r3, r4, r6 corrupted
- * ?r5 = mach_info pointer in physical address space
- */
-__lookup_machine_type:
- ? ? ? adr ? ? r3, __lookup_machine_type_data
- ? ? ? ldmia ? r3, {r4, r5, r6}
- ? ? ? sub ? ? r3, r3, r4 ? ? ? ? ? ? ? ? ? ? ?@ get offset between virt&phys
- ? ? ? add ? ? r5, r5, r3 ? ? ? ? ? ? ? ? ? ? ?@ convert virt addresses to
- ? ? ? add ? ? r6, r6, r3 ? ? ? ? ? ? ? ? ? ? ?@ physical address space
-1: ? ? ldr ? ? r3, [r5, #MACHINFO_TYPE] ? ? ? ?@ get machine type
- ? ? ? teq ? ? r3, r1 ? ? ? ? ? ? ? ? ? ? ? ? ?@ matches loader number?
- ? ? ? beq ? ? 2f ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?@ found
- ? ? ? add ? ? r5, r5, #SIZEOF_MACHINE_DESC ? ?@ next machine_desc
- ? ? ? cmp ? ? r5, r6
- ? ? ? blo ? ? 1b
- ? ? ? mov ? ? r5, #0 ? ? ? ? ? ? ? ? ? ? ? ? ?@ unknown machine
-2: ? ? mov ? ? pc, lr
-ENDPROC(__lookup_machine_type)
-
-/*
- * Look in arch/arm/kernel/arch.[ch] for information about the
- * __arch_info structures.
- */
- ? ? ? .align ?2
- ? ? ? .type ? __lookup_machine_type_data, %object
-__lookup_machine_type_data:
- ? ? ? .long ? .
- ? ? ? .long ? __arch_info_begin
- ? ? ? .long ? __arch_info_end
- ? ? ? .size ? __lookup_machine_type_data, . - __lookup_machine_type_data

?/* Determine validity of the r2 atags pointer. ?The heuristic requires
?* that the pointer be aligned, in the first 16k of physical RAM and

@@ -107,8 +32,6 @@ __lookup_machine_type_data:

?* of this function may be more lenient with the physical address and
?* may also be able to move the ATAGS block if necessary.
?*
- * r8 ?= machinfo
- *
?* Returns:
?* ?r2 either valid atags pointer, or zero
?* ?r5, r6 corrupted

@@ -183,17 +106,6 @@ __mmap_switched_data:

? ? ? ?.size ? __mmap_switched_data, . - __mmap_switched_data

?/*
- * This provides a C-API version of __lookup_machine_type
- */
-ENTRY(lookup_machine_type)
- ? ? ? stmfd ? sp!, {r4 - r6, lr}
- ? ? ? mov ? ? r1, r0
- ? ? ? bl ? ? ?__lookup_machine_type
- ? ? ? mov ? ? r0, r5
- ? ? ? ldmfd ? sp!, {r4 - r6, pc}
-ENDPROC(lookup_machine_type)
-
-/*
?* This provides a C-API version of __lookup_processor_type
?*/
?ENTRY(lookup_processor_type)

diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index 814ce1a..6b1e0ad 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S

@@ -44,9 +44,6 @@ ENTRY(stext)

? ? ? ?bl ? ? ?__lookup_processor_type ? ? ? ? @ r5=procinfo r9=cpuid
? ? ? ?movs ? ?r10, r5 ? ? ? ? ? ? ? ? ? ? ? ? @ invalid processor (r5=0)?
? ? ? ?beq ? ? __error_p ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? @ yes, error 'p'
- ? ? ? bl ? ? ?__lookup_machine_type ? ? ? ? ? @ r5=machinfo
- ? ? ? movs ? ?r8, r5 ? ? ? ? ? ? ? ? ? ? ? ? ?@ invalid machine (r5=0)?
- ? ? ? beq ? ? __error_a ? ? ? ? ? ? ? ? ? ? ? @ yes, error 'a'

? ? ? ?adr ? ? lr, BSYM(__after_proc_init) ? ? @ return (PIC) address
?ARM( ?add ? ? pc, r10, #PROCINFO_INITFUNC ? ? )

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 06aed19..084db6c 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S

@@ -87,14 +87,10 @@ ENTRY(stext)

? ? ? ?movs ? ?r10, r5 ? ? ? ? ? ? ? ? ? ? ? ? @ invalid processor (r5=0)?
?THUMB( it ? ? eq ) ? ? ? ? ? ?@ force fixup-able long branch encoding
? ? ? ?beq ? ? __error_p ? ? ? ? ? ? ? ? ? ? ? @ yes, error 'p'
- ? ? ? bl ? ? ?__lookup_machine_type ? ? ? ? ? @ r5=machinfo
- ? ? ? movs ? ?r8, r5 ? ? ? ? ? ? ? ? ? ? ? ? ?@ invalid machine (r5=0)?
- THUMB( it ? ? eq ) ? ? ? ? ? ?@ force fixup-able long branch encoding
- ? ? ? beq ? ? __error_a ? ? ? ? ? ? ? ? ? ? ? @ yes, error 'a'

? ? ? ?/*
? ? ? ? * r1 = machine no, r2 = atags,
- ? ? ? ?* r8 = machinfo, r9 = cpuid, r10 = procinfo
+ ? ? ? ?* r9 = cpuid, r10 = procinfo
? ? ? ? */
? ? ? ?bl ? ? ?__vet_atags
?#ifdef CONFIG_SMP_ON_UP

@@ -108,7 +104,7 @@ ENTRY(stext)

? ? ? ?/*
? ? ? ? * The following calls CPU specific code in a position independent
? ? ? ? * manner. ?See arch/arm/mm/proc-*.S for details. ?r10 = base of
- ? ? ? ?* xxx_proc_info structure selected by __lookup_machine_type
+ ? ? ? ?* xxx_proc_info structure selected by __lookup_processor_type
? ? ? ? * above. ?On return, the CPU will be ready for the MMU to be
? ? ? ? * turned on, and r0 will hold the CPU control register value.
? ? ? ? */

@@ -127,7 +123,6 @@ ENDPROC(stext)

?* amount which are required to get the kernel running, which
?* generally means mapping in the kernel code.
?*
- * r8 ?= machinfo
?* r9 ?= cpuid
?* r10 = procinfo
?*

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 7c5499d..eb952a7 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c

@@ -308,7 +308,44 @@ static void __init cacheid_init(void)

?* already provide the required functionality.
?*/
?extern struct proc_info_list *lookup_processor_type(unsigned int);
-extern struct machine_desc *lookup_machine_type(unsigned int);
+
+static void __init early_print(const char *str, ...)
+{
+ ? ? ? extern void printascii(const char *);
+ ? ? ? char buf[256];
+ ? ? ? va_list ap;
+
+ ? ? ? va_start(ap, str);
+ ? ? ? vsnprintf(buf, sizeof(buf), str, ap);
+ ? ? ? va_end(ap);
+
+#ifdef CONFIG_DEBUG_LL
+ ? ? ? printascii(buf);
+#endif
+ ? ? ? printk("%s", buf);
+}
+
+static struct machine_desc * __init lookup_machine_type(unsigned int type)
+{
+ ? ? ? extern struct machine_desc __arch_info_begin[], __arch_info_end[];
+ ? ? ? struct machine_desc *p;
+
+ ? ? ? for (p = __arch_info_begin; p < __arch_info_end; p++)
+ ? ? ? ? ? ? ? if (type == p->nr)
+ ? ? ? ? ? ? ? ? ? ? ? return p;
+
+ ? ? ? early_print("\n"
+ ? ? ? ? ? ? ? "Error: unrecognized/unsupported machine ID (r1 = 0x%08x).\n\n"
+ ? ? ? ? ? ? ? "Available machine support:\n\nID (hex)\tNAME\n", type);
+
+ ? ? ? for (p = __arch_info_begin; p < __arch_info_end; p++)
+ ? ? ? ? ? ? ? early_print("%08x\t%s\n", p->nr, p->name);
+
+ ? ? ? early_print("\nPlease check your kernel config and/or bootloader.\n");
+
+ ? ? ? while (true)
+ ? ? ? ? ? ? ? /* can't use cpu_relax() here as it may require MMU setup */;
+}

?static void __init feat_v6_fixup(void)
?{