740cf98f0f
linux_trampoline.c generation is broken with latest crossgcc-i386 toolchain. Fix the issue to enable the building. ../cbfstool/linux_trampoline.S: Assembler messages: ../cbfstool/linux_trampoline.S💯 Error: no instruction mnemonic suffix given and no register operands; can't size instruction <builtin>: recipe for target '../cbfstool/linux_trampoline.o' failed TEST=Build and boot on intel/archercity CRB cd util/cbfstool/ rm linux_trampoline.c make linux_trampoline.c Change-Id: I7faca296f946bb4e9fd510661357925e5dcf9a6b Signed-off-by: Shuo Liu <shuo.liu@intel.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/82704 Reviewed-by: Nico Huber <nico.h@gmx.de> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com>
197 lines
5.1 KiB
ArmAsm
197 lines
5.1 KiB
ArmAsm
/* linux_trampoline */
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/* SPDX-License-Identifier: GPL-2.0-only */
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/* NOTE: THIS CODE MUST REMAIN POSITION INDEPENDENT
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* IT SHOULDN'T USE THE STACK
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* AND IN GENERAL EXPECT NOTHING BUT RAM TO WORK
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*/
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.code32
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.data
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#include "linux_trampoline.h"
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#define HEADER_SIG 0x4f49424c // LBIO little endian
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#define CB_TAG_FORWARD 0x11
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#define CB_TAG_MEMORY 0x1
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#define CB_TAG_FRAMEBUFFER 0x12
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#define CB_TAG_ACPI_RSDP 0x43
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#define ACPI_RSDP_ADDR 0x70
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#define E820_NR_OFFSET 0x1e8
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#define PROTOCOL_VERSION 0x206
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#define LINUX_ENTRY_OFFSET 0x214
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#define E820_OFFSET 0x2d0
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.trampoline_start:
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cld
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xor %edx, %edx
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mov $0, %ecx
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.headerSearch:
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mov $0x10000, %ebx
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add %ecx, %ebx
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mov (%ecx), %eax
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cmp $HEADER_SIG, %eax
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je .headerSearchDone // found the header
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add $16, %ecx
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cmp %ecx, %ebx
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jne .headerSearch
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.headerSearchDone:
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cmp %ecx, %ebx // reached the end == not found anything?
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je 2f // give up
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// we assume the checksum is okay, no test
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mov 4(%ecx), %ebx
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add %ecx, %ebx // ebx = cb_header + header_bytes
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mov 20(%ecx), %ecx // ecx = table_entries
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.tableScan:
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cmp $CB_TAG_FORWARD, (%ebx)
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jne .testMemory
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/* forward tag: assume 32bit pointer */
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mov 8(%ebx), %ecx
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jmp .headerSearch
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.testMemory:
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cmp $CB_TAG_MEMORY, (%ebx)
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jne .testAcpiRsdp
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/* memory tag: copy e820 map and entry count. also determine alt_mem_k */
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mov 4(%ebx), %eax
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sub $8, %eax
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shr $2, %eax /* eax = number of dwords of e820 data */
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/*
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* Historically linux had space for 32 entries. This limit was increased in
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* the year 2005 (Linux 2.6.11) to hold up to 128 entries.
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* Assume 128 entries when the boot protocol version is 2.04+.
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*/
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cmpw $0x0204, (LINUX_PARAM_LOC + PROTOCOL_VERSION)
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jge .e820big /* protocol version >= 2.04 can handle 128 entries of 5 dwords */
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cmp $(32 * 5), %eax /* linux wants at most 32 entries of 5 dwords */
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jng 1f
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mov $(32 * 5), %eax /* only copy 32 entries */
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jmp 1f
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.e820big:
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cmp $(128 * 5), %eax /* linux wants at most 128 entries of 5 dwords */
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jng 1f
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mov $(128 * 5), %eax /* only copy 128 entries */
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1:
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mov %eax, %esi
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mov $5, %edi
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div %edi
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mov %eax, (LINUX_PARAM_LOC + E820_NR_OFFSET)
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mov %esi, %eax
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xchg %eax, %ecx
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lea 8(%ebx), %esi /* e820 data source */
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mov $(LINUX_PARAM_LOC + E820_OFFSET), %edi
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rep movsl
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xchg %eax, %ecx
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/* e820 and LB_TAG_MEMORY type don't fully match: remap unknown type to 2, reserved memory */
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mov (LINUX_PARAM_LOC + E820_NR_OFFSET), %eax
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mov $(LINUX_PARAM_LOC + E820_OFFSET), %edi
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.test_e820_entry:
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cmp $0, %eax
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je .endScan
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cmp $12, 16(%edi) /* type */
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jng .next_e820_entry
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/* Fixup the type to 2, reserved memory */
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movl $2, 16(%edi)
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.next_e820_entry:
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dec %eax
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add $20, %edi
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jmp .test_e820_entry
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.testAcpiRsdp:
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cmp $CB_TAG_ACPI_RSDP, (%ebx)
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jne .testFramebuffer
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mov 8(%ebx), %eax
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mov %eax, (LINUX_PARAM_LOC + ACPI_RSDP_ADDR)
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mov 12(%ebx), %eax
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mov %eax, (LINUX_PARAM_LOC + ACPI_RSDP_ADDR + 4)
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jmp .endScan
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.testFramebuffer:
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cmp $CB_TAG_FRAMEBUFFER, (%ebx)
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jne .endScan
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cmpw $0x020f, (LINUX_PARAM_LOC + PROTOCOL_VERSION)
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jge .framebufferSetup /* protocol version >= 2.15 can handle 64-bit address */
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cmpl $0, 0x0c(%ebx) /* check if upper 32-bit of framebuffer address are 0 */
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jne .endScan
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.framebufferSetup:
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mov $LINUX_PARAM_LOC, %edi /* translate the framebuffer entry into Linux' struct screen_info */
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mov 0x08(%ebx), %eax /* physical_address */
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mov %eax, 0x18(%edi) /* -> lfb_base */
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mov 0x0c(%ebx), %eax /* physical_address */
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mov %eax, 0x3a(%edi) /* -> ext_lfb_base */
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mov 0x10(%ebx), %eax /* x_resolution */
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mov %ax, 0x12(%edi) /* -> lfb_width */
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mov 0x14(%ebx), %eax /* y_resolution */
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mov %ax, 0x14(%edi) /* -> lfb_height */
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mov 0x18(%ebx), %edx /* bytes_per_line */
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mov %dx, 0x24(%edi) /* -> lfb_linelength */
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mul %edx /* bytes_per_line * y_resolution */
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mov %eax, 0x1c(%edi) /* -> lfb_size */
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movzbw 0x1c(%ebx), %ax /* bits_per_pixel */
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mov %ax, 0x16(%edi) /* -> lfb_depth */
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mov $4, %esi /* Copy 4 color components' pos and size, each 1 byte. */
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1:
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mov 0x1b(%ebx, %esi, 2), %ax
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rol %ax /* Order is reversed for Linux, hence swap. */
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mov %ax, 0x24(%edi, %esi, 2)
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dec %esi
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jnz 1b
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#define VIDEO_CAPABILITY_64BIT_BASE (1 << 1)
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movl $VIDEO_CAPABILITY_64BIT_BASE, 0x36(%edi)
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#define LFB_EFI_SIMPLE 0x70 /* VIDEO_TYPE_EFI in Linux */
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movb $LFB_EFI_SIMPLE, 0x0f(%edi) /* -> orig_video_isVGA */
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.endScan:
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add 4(%ebx), %ebx
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dec %ecx
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jnz .tableScan
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/* Setup basic code and data segment selectors for Linux
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**
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** Flat code segment descriptor:
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** selector: 0x10
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** base : 0x00000000
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** limit : 0xFFFFFFFF
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** type : code, execute, read
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**
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** Flat data segment descriptor:
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** selector: 0x18
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** base : 0x00000000
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** limit : 0xFFFFFFFF
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** type : data, read/write
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**
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** Use TRAMPOLINE_ENTRY_LOC as a scratchpad.
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*/
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mov $TRAMPOLINE_ENTRY_LOC, %eax
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movl $0x0000ffff, 16(%eax) // Set up the 2 new descriptors
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movl $0x00cf9b00, 20(%eax)
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movl $0x0000ffff, 24(%eax)
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movl $0x00cf9300, 28(%eax)
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movb $0x2b, 0(%eax) // Set the size
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movl %eax, 2(%eax) // Set pointer to new GDT
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lgdt (%eax) // Load it
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/* finally: jump to kernel */
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mov $LINUX_PARAM_LOC, %esi
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jmp *(LINUX_PARAM_LOC + LINUX_ENTRY_OFFSET)
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2:
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hlt
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jmp 2b
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.trampoline_end:
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